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This PDQ cancer information summary provides comprehensive, peer-reviewed information for health professionals about nutrition before, during, and after cancer treatment. This summary is reviewed regularly and updated as necessary by the PDQ Supportive and Palliative Care Editorial Board.
Information about the following is included in this summary:
This summary is intended as a resource to inform and assist clinicians and other health professionals who care for cancer patients during and after cancer treatment. It does not provide formal guidelines or recommendations for making health care decisions. Information in this summary should not be used as a basis for reimbursement determinations.
This summary is also available in a patient version, which is written in less technical language, and in Spanish.
Nutrition plays major (but not always fully understood) roles in many aspects of cancer development and treatment. [1] Malnutrition is a common problem in cancer patients that has been recognized as an important component of adverse outcomes, including increased morbidity and mortality and decreased quality of life. Weight loss has been identified as an indicator of poor prognosis in cancer patients. [2] It has been shown that at the time of diagnosis, 80% of patients with upper gastrointestinal cancer and 60% of patients with lung cancer have already experienced a significant weight loss, [3] generally defined as at least a 10% loss of body weight in 6 months' time. [4] Good nutrition practices can help cancer patients maintain weight and the body's nutrition stores, offering relief from nutrition impact symptoms and improving quality of life. [5] Poor nutrition practices, which can lead to undernutrition, can contribute to the incidence and severity of treatment side effects and increase the risk of infection, thereby reducing chances for survival. [6] Nutrition impact symptoms are those symptoms that impede oral intake. They include, but are not limited to, anorexia, nausea, vomiting, diarrhea, constipation, stomatitis, mucositis, dysphagia, alterations in taste and smell, pain, depression, and anxiety. [7] Early recognition and detection of risk for malnutrition through nutrition screening followed by comprehensive assessments is increasingly recognized as imperative in the development of standards of quality of care in oncology practices. [2] Undesirable weight gain may be an effect of chemotherapy treatment for early-stage cancers, possibly resulting from decreases in resting metabolism. [8] Consequently, the eating practices of individuals diagnosed with cancer should be assessed throughout the continuum of care to reflect the changing goals of nutritional therapy.
Nutritional status is often jeopardized by the natural progression of neoplastic disease. (Refer to the Tumor-Induced Effects on Nutritional Status section.) Alterations in nutritional status begin at diagnosis, when psychosocial issues may also adversely affect dietary intake, and proceed through treatment and recovery. Protein-calorie malnutrition (PCM) is the most common secondary diagnosis in individuals diagnosed with cancer, stemming from the inadequate intake of carbohydrate, protein, and fat to meet metabolic requirements and/or the reduced absorption of macronutrients. PCM in cancer results from multiple factors most often associated with anorexia, cachexia, and the early satiety sensation frequently experienced by individuals with cancer. These factors range from altered tastes to a physical inability to ingest or digest food, leading to reduced nutrient intake. Cancer-induced abnormalities in the metabolism of the major nutrients also increase the incidence of PCM. Such abnormalities may include glucose intolerance and insulin resistance, increased lipolysis, and increased whole-body protein turnover. If left untreated, PCM can lead to progressive wasting, weakness, and debilitation as protein synthesis is reduced and lean body mass is lost, possibly leading to death. [9]
Anorexia, the loss of appetite or desire to eat, is typically present in 15% to 25% of all cancer patients at diagnosis and may also occur as a side effect of treatments. Anorexia is an almost universal side effect in individuals with widely metastatic disease [10] [11] because of physiologic alterations in metabolism during carcinogenesis. (Refer to the Tumor-induced Effects on Nutritional Status section.) Anorexia can be exacerbated by chemotherapy and radiation therapy side effects such as taste and smell changes, nausea, and vomiting. Surgical procedures, including esophagectomy and gastrectomy, may produce early satiety, a premature feeling of fullness. [4] Depression, loss of personal interests or hope, and anxious thoughts may be enough to bring about anorexia and result in PCM. [3] Evidence-based recommendations have been published describing various approaches to the problems of cancer-related fatigue, anorexia, depression, and dyspnea. [12] Other systemic or local effects of cancer or its treatment that may affect nutritional status include hypermetabolism, sepsis, malabsorption, and obstructions. [9]
Anorexia can hasten the course of cachexia, [3] a progressive wasting syndrome evidenced by weakness and a marked and progressive loss of body weight, fat, and muscle. Cachexia is estimated to be the immediate cause of death in 20% to 40% of cancer patients; it can develop in individuals who appear to be eating adequate calories and protein but have primary cachexia whereby tumor-related factors prevent maintenance of fat and muscle. Particularly at risk are patients with diseases of the gastrointestinal tract.
The etiology of cancer cachexia is not entirely understood. Cachexia can manifest in individuals with metastatic cancer as well as in individuals with localized disease. Several theories suggest that cachexia is caused by a complex mix of variables, including tumor-produced factors and metabolic abnormalities. [11] The basal metabolic rate in cachectic individuals is not adaptive, that is, it may be increased, decreased, or normal. [13] Some individuals do respond to nutrition therapy, but most will not see a complete reversal of the syndrome, even with aggressive therapy. [6] Thus, the most prudent and advantageous approach to cachexia is the prevention of its initiation through nutrition monitoring and nutrition intervention. [14]
Reference citations in some PDQ Supportive and Palliative Care information summaries may include links to external Web sites that are operated by individuals or organizations for the purpose of marketing or advocating the use of specific treatments or products. These reference citations are included for informational purposes only. Their inclusion should not be viewed as an endorsement of the content of the Web sites or of any treatment or product by the PDQ Supportive and Palliative Care Editorial Board or the National Cancer Institute (NCI).
Nutritional status can be compromised in direct response to tumor-induced alterations in metabolism. Also known as cachexia, this condition is one of advanced protein-calorie malnutrition and is characterized by involuntary weight loss, muscle wasting, and decreased quality of life. [1] [2] Tumor-induced weight loss occurs frequently in patients with solid tumors of the lung, pancreas, and upper gastrointestinal tract and less often in patients with breast cancer or lower gastrointestinal cancer. Although anorexia may also be present, the energy deficit alone does not explain the pathogenesis of cachexia. Several factors have been proposed. [3] Mediators including cytokines, neuropeptides, neurotransmitters, and tumor-derived factors are postulated to contribute to this syndrome. [4] Products of host tissues, such as tumor necrosis factor-α, interleukin-1, interleukin-6, interferon-γ, and leukemia inhibitor factor, as well as tumor products that have a direct catabolic effect on host tissues, such as lipid-mobilizing factor and proteolysis-inducing factor (not established as definite in humans), have all been identified as mediators of this complex syndrome. [3] Altered metabolism of fats, proteins, and carbohydrates is evident in cancer patients with cachexia. Tumors may induce impaired glucose uptake and glucose oxidation, leading to an increased glycolysis. [5] Weight loss can occur from a decrease in energy intake, an increase in energy expenditure, or a combination of the two. Although anorexia is a common symptom of cancer patients, studies have shown that increased caloric intake either by the oral route or by supplementation with total parenteral nutrition has failed to counteract the wasting process. This supports the theory that the aberrant metabolic rate is the direct response by the tumor and the immune system to disrupt the pathways that regulate the homeostatic loop of body-weight regulation. [4]
Current studies suggest that the basal metabolic rate serves as a possible prognostic indicator of survival. As cancer progresses, the basal metabolic rate declines and cachexia occurs, reducing long-term survival. [6] Although alterations in overall basal metabolic rates have not been observed by some, [7] increased basal metabolic rates have been reported in pediatric, [8] breast, [9] lung, [8] malnourished, [10] and other [11] cancer patient populations; however, the discrepancy may be related to the stage of cancer progression. [12] Nutritional support therapies aimed at preserving lean muscle mass and subcutaneous adipose stores despite this altered metabolic rate may ultimately improve patients' quality of life and impact overall survival.
Although an individual’s nutritional status may be compromised initially by the diagnosis of cancer, thorough nutritional screening procedures and the timely implementation of nutritional therapies may markedly improve the patient’s outcome. Symptoms and side effects may sometimes be managed by a combination of dietary and pharmacologic interventions.
Several approaches to the treatment of cancer cachexia have been reported, and a variety of agents have been studied for their effects on appetite and weight. The decision to use pharmacological treatment to improve a patient’s appetite should be based on the patient’s desires, current medical condition, and life expectancy. Table 1 lists several medications that have been proposed to treat the symptoms of cancer cachexia. [13] However, the management of cachexia remains a complex challenge, and integrated multimodal treatment targeting the different factors involved has been proposed. In a phase III study, patients were randomly assigned to receive megestrol acetate, eicosapentaenoic acid, L-carnitine, thalidomide, or megestrol acetate plus L-carnitine and thalidomide. Interim analysis of 125 patients suggested the most effective treatment would be a combination regimen. The optimal combination is the goal of ongoing research. [14]
| Drug Category | Common Drugs Used | Comments |
|---|---|---|
| Progestational agents | megestrol acetate | Multiple investigations report appetite stimulant activity and weight gain with use. Body composition of weight gain indicates increased body fat stores instead of lean body tissue. Increased risk of thromboembolism with doses >800 mg/day is an apparent trend. Studies suggest improved effectiveness in patients with better digestive function; therefore, targeted nutritional strategies such as digestive enzymes or elemental diets may be useful. [13] [15] |
| medroxyprogesterone | ||
| Glucocorticoids | dexamethasone | Mechanism of appetite stimulation is unknown but likely related to anti-inflammatory and euphoric actions. Studies report positive but short-lived effects on clinical outcomes such as appetite and quality of life, with minimal or no effect on weight gain. Risk of adverse effects such as muscle wasting and immunosuppression limit use for long-term use for appetite stimulation. [13] [16] |
| methylprednisolone | ||
| prednisolone | ||
| Cannabinoids | dronabinol | Inconsistent evidence of clinical effectiveness in cancer patients. Studies of dronabinol alone or with megestrol acetate have not shown superior benefit in promoting weight gain and appetite. [13] [17] [18] [19] [20] |
| Antihistamines | cyproheptadine | Not studied well in cancer patients. A randomized placebo-controlled trial in patients with advanced cancer reported no difference in weight changes and progressive weight loss in both groups. Sedation is a frequent adverse effect that may limit usefulness in cancer patients. [13] [21] |
| Antidepressants/ antipsychotics | mirtazapine | Clinical data supporting routine use in cancer patients are lacking. Further studies are needed. [16] |
| olanzapine | ||
| Anti-inflammatory agents | thalidomide | All have been shown to decrease TNF-alpha. Mixed results in clinical trials regarding weight gain and appetite stimulation. One published randomized placebo-controlled trial evaluated the safety and efficacy of thalidomide, 200 mg daily, in patients with advanced pancreatic cancer and weight loss of at least 10% of premorbid weight. Thalidomide group showed a significant difference in weight loss compared with the placebo group, indicating the drug's ability to safely decrease weight loss and loss of lean body mass in the patients studied. [22] Preliminary clinical studies and laboratory studies of the polyunsaturated fatty acid EPA have suggested a benefit to cancer patients; however, subsequent large comparative studies failed to reproduce this benefit. [23] [24] |
| pentoxifylline | ||
| melatonin | ||
| omega 3 fatty acids (EPA) | ||
| Metabolic inhibitors | hydrazine sulfate | Not approved by the U.S. FDA for marketing in the United States. [16] |
| Anabolic agents | oxandrolone | Used in an attempt to stimulate muscle anabolism. Limited published reports of successful appetite stimulation in cancer patients. [16] |
| nandrolone decanoate | ||
| fluoxymesterone | ||
| EPA = eicosapentaenoic acid; TNF-alpha = tumor necrosis factor-alpha; U.S. FDA = United States Food and Drug Administration. | ||
Weight loss associated with cancer and its treatment may be secondary to a host of symptoms and side effects. Early intervention using appropriate nutrition and pharmacologic symptom-management strategies can keep weight loss at bay. The drug categories typically used to manage these symptoms and side effects include the following: [25]
(Refer to the Nutrition Screening and Assessment section and the Nutritional Suggestions for Symptom Management section.)
The nutritional status of patients diagnosed with cancer entering the treatment process varies. Not everyone begins therapy with anorexia, weight loss, and other symptoms of nutritional problems. For patients who have such symptoms, however, anticancer therapies can complicate the treatment and expected recovery. Many individuals also present with preexisting comorbid diseases and illnesses that further complicate their treatment. Surgery, chemotherapy, and radiation can have a direct (or mechanical) and/or an indirect (or metabolic) negative effect on nutritional status. The success of the anticancer therapy will be influenced by a patient’s ability to tolerate therapy, which will, in turn, be affected by nutritional status preceding treatment. The treating clinician should assess baseline nutritional status (see the Nutrition Screening and Assessment section) and be aware of the possible implications of the various therapies. Patients receiving aggressive cancer therapies typically need aggressive nutrition management.
Surgery is often the primary treatment modality for cancer. Approximately 60% of individuals diagnosed with cancer will have some type of cancer-related surgery. [1] Malnourished surgical patients are at increased risk for postoperative morbidity and mortality. Steps should be taken to attempt to correct nutritional macronutrient and micronutrient deficiencies before surgery if time permits. [2] This involves identification and assessment of the problem, with the possible use of oral liquid nutritional supplements, enteral or parenteral nutritional support, and/or use of pharmacologic therapies to stimulate the appetite (see the Tumor-Induced Effects on Nutritional Status section). [2]
Depending on the procedure, surgery can cause mechanical or physiologic barriers to adequate nutrition, such as a short gut that results in malabsorption after bowel resection. [2] In addition to these mechanical barriers, surgery frequently imposes an immediate metabolic response that increases the energy needs and changes the nutrient requirements necessary for wound healing and recovery at a time when baseline needs and requirements are often not being met.
The following sections highlight various surgical issues for specific cancers. Nutritional complications are usually most notable and severe with cancerous growths and anticancer therapy involving the alimentary canal.
Alcohol abuse is a major risk factor for cancer in the head and neck region and can itself lead to malnutrition. [3] Cancer occurring in this region coupled with curative or palliative surgery can alter a patient’s ability to speak, chew, salivate, swallow, smell, taste, and/or see. [2] Treatment for head and neck cancer can have a profound negative effect on nutritional status.
Nutrition assessment is advised at the initial visit. Clinicians should anticipate additional complicating factors such as the side effects of combined modality therapy (chemotherapy and radiation therapy), [4] as well as the increased nutritional requirements for withstanding these therapies. Because head and neck cancer patients are often malnourished at diagnosis and will undergo therapies that may directly affect their ability to eat, many of these individuals have enteral feeding tubes placed prophylactically before undergoing surgery. [2]
Surgery may take a tremendous toll on the body, but it has reduced mortality and morbidity from gastrointestinal cancers. [2] Anticancer therapy for aerodigestive cancers (e.g., esophageal, gastric, pancreatic, liver, gallbladder, bile duct, and small and large intestine) can result in gastric paresis, alterations in digestion, malabsorption of nutrients, hyperglycemia, elevated lipid levels, hepatic encephalopathy, fluid and electrolyte imbalance, anastomotic and chyle leaks, dumping syndrome, and vitamin and mineral deficiencies. [2] The use of enteral nutritional support is common in the treatment of gastrointestinal cancers. The feeding tube may be placed in the stomach (gastrostomy) or down into the jejunum (jejunostomy). [2] [5]
Many individuals experience fatigue, pain, and loss of appetite and are unable to consume their regular diet as the result of surgery. [2] Prompt nutritional therapy can help relieve or reduce these problems. Avoiding carbonated or known gas-producing foods will help, as will altering the fiber content in the diet to encourage bowel regularity. A well-balanced diet that contains the recommended amounts of essential nutrients and calories will help promote good wound healing. Finally, proper nutrition and adequate rest may help prevent or treat fatigue.
In 2000, more than 90 different chemotherapy agents were approved for use. These agents are divided into several functional categories. Chemotherapy agents can be used in combination or as single agents, depending on the disease type and health condition of the individual. [6]
Unlike surgery and radiation therapy, cancer chemotherapy is a systemic treatment (not a localized treatment) that affects the whole body (not just a specific part). [7] Consequently, there are potentially more side effects with chemotherapy than with surgery and radiation therapy. The most commonly experienced nutrition-related side effects are anorexia, taste changes, early satiety, nausea, vomiting, mucositis/esophagitis, diarrhea, and constipation (see the Nutritional Suggestions for Symptom Management section). Because side effects of chemotherapy, as well as the cancer itself, can greatly affect nutritional status, healthcare providers need to anticipate possible problems and educate the patient about them [7] in an effort to prevent malnutrition and weight loss (see the Nutrition Screening and Assessment section). Malnutrition and weight loss can affect a patient’s ability to regain health and acceptable blood counts between chemotherapy cycles; this can directly affect the patient's ability to stay on treatment schedules, which is important in achieving a successful outcome.
Nutritional support or high-calorie/high-protein liquid supplements may be used in an effort to maintain adequate calorie and nutrient intake. Special formulas are available for people with secondary medical conditions such as hyperglycemia or compromised renal function.
Nutritional support during radiation therapy is vital. The effect of radiation therapy on healthy tissue in the treatment field can produce changes in normal physiologic function that may ultimately diminish a patient’s nutritional status by interfering with ingestion, digestion, or absorption of nutrients. Medications such as pilocarpine (Salagen) may be useful in treating the xerostomia (dry mouth) that accompanies radiation therapy. This medicine may reduce the need for artificial saliva agents or other oral comfort agents such as hard candy or sugarless gum.
The side effects of radiation therapy depend on the area irradiated, total dose, fractionation, duration, and volume irradiated. Most side effects are acute, begin around the second or third week of treatment, and diminish 2 or 3 weeks after radiation therapy is completed. Some side effects can be chronic and continue or occur after treatment has been completed. [8]
Individuals receiving radiation therapy to any part of the gastrointestinal tract are more susceptible to nutrition-related side effects. [9] Patients most at risk for developing nutrition-related side effects are those whose cancers involve the aerodigestive tract, including the head and neck, lungs, esophagus, cervix, uterus, colon, rectum, and pancreas. Patients who are receiving radiation therapy to the head and neck region may present to radiation therapy with preexisting malnutrition secondary to an inability to ingest foods because of the disease itself or because of surgery to treat the disease. Many of these patients have a history of high alcohol intake, which also places them at a higher nutritional risk. These individuals are generally at the greatest risk for developing significant nutrition problems and severe weight loss. [10] In a placebo-controlled, double-blind randomized study of 57 patients receiving radiation therapy for head/neck and lung cancer, megestrol acetate (MA) was administered at a dose of 800 mg per day. Patients who received MA demonstrated significant advantages in weight maintenance and some aspects of quality of life. [11]
Nutrition intervention is based on symptom management. Patients who maintain good nutrition are more likely to tolerate the side effects of treatment. Adequate calories and protein can help maintain patient strength and prevent body tissues from further catabolism. Individuals who do not consume adequate calories and protein use stored nutrients as an energy source, which leads to protein wasting and further weight loss.
Some of the more common nutrition-related side effects caused by irradiation to the head and neck include taste alterations or aversions, odynophagia (pain produced by swallowing), xerostomia, thick saliva, mucositis, dysphagia, and stricture of the upper esophagus. [4] Thoracic irradiation may be associated with esophagitis, dysphagia, or esophageal reflux. Diarrhea, nausea, vomiting, enteritis, and malabsorption of nutrients are possible side effects of pelvic or abdominal radiation. [12] (See the Nutritional Suggestions for Symptom Management section.) A prospective, randomized study of patients with colorectal cancer receiving radiation therapy demonstrated that concurrent individualized dietary counseling can improve patients' nutritional intake, status, and quality of life. These improvements, in turn, may reduce radiation-induced morbidity. [13] Patients receiving high-dose radiation or bone marrow transplant should consult with a dietician.
Suggestions for appropriate dietary modifications based on nutrition-related symptoms are widely available for patient and healthcare professional use. For a full listing of dietary suggestions see the Tumor-Induced Effects on Nutritional Status section. A list of appropriate references is also included below.
Many patients who are undergoing radiation therapy will benefit from nutritional supplements between meals. [14] Aggressive nutritional support is indicated when oral intake alone fails to maintain an individual’s weight. Tube feedings are used more frequently than parenteral nutrition, primarily to preserve gastrointestinal function. Tube feedings are usually well tolerated, pose less risk to the patient than parenteral feedings, and are more cost effective. Numerous studies demonstrate the benefit of enteral feedings initiated at the onset of treatment, specifically treatment to head and neck regions, before significant weight loss has occurred. [15] [16] [17]
Many nutrition-related side effects result from radiation therapy. Quality of life and nutritional intake can be improved by managing these side effects through appropriate medical nutritional therapy and dietary modifications.
Monoclonal antibodies, which are used to block cancer-cell receptors for growth-stimulating factors, may cause a cascade of symptoms; however, the symptoms most likely to impact nutritional status are fever, nausea, vomiting, and diarrhea. [1] Interferon (a nonspecific immunotherapy) has had the noted nutrition-related side effects of anorexia, nausea, vomiting, and fatigue. [1] Interleukin-2, approved by the U.S. Food and Drug Administration for the single-agent treatment of metastatic renal cell cancer, can also cause symptoms such as fatigue, nausea, vomiting, and diarrhea. [1] [18] Response to interleukin-2 treatment varies; some patients gain weight, and some require nutritional support. [18] However, most patients taking interleukin gain weight. Finally, granulocyte-macrophage colony-stimulating factor, a very common therapy used to increase the production of white blood cells, may also cause fever, nausea, vomiting, and diarrhea. [1]
If ignored, these symptoms can cause gradual or drastic weight loss (depending on the severity of the symptoms), which may lead to malnutrition. Malnutrition can complicate the expected healing and recovery process (see the Nutritional Suggestions for Symptom Management section).
Hemopoietic and stem cell transplant patients have special nutritional requirements. [19] Before their transplant, patients receive high-dose chemotherapy and may also be treated with total-body irradiation (TBI). [20] These treatments, in addition to medications used during transplantation, frequently result in nutritional side effects, which may affect patients' ability to consume an adequate diet. The goal of nutritional support should be the maintenance of nutritional status and protein stores. In addition, transplant patients are at very high risk for neutropenia, an abnormally small number of neutrophils in the blood, that makes them susceptible to multiple infections. [21] [22]
To reduce the risk of infections related to stem cell transplantation, most healthcare setting guidelines recommend only cooked and processed foods and restrict raw vegetables and fresh fruits that could cause a food-related infection. Specific dietary restrictions and their duration depend on the type of transplant and the cancer site. In addition to specific dietary restrictions, food safety guidelines should be reviewed and stressed with all transplant patients.
The chemotherapy regimen and complications associated with the transplant may result in numerous problems that adversely affect nutritional intake and status. [23] During the transplant process, patients may experience nutrition-related side effects such as taste changes, oral dryness, thick saliva, mouth and throat sores, nausea and vomiting, diarrhea, constipation, lack of appetite/weight loss, and weight gain. Often during the first few weeks posttransplant, patients are fed intravenously to ensure that they receive sufficient calories, protein, vitamins, minerals, and fluids. [24]
Many patients experience mouth and throat sores 2 to 4 weeks after transplantation. Mucositis is the general term that refers to the erythema, swelling, and ulceration of the intraoral soft-tissue structures and the oral and esophageal mucosa in response to the cytotoxic effect of radiation therapy and high-dose chemotherapy. Mouth and throat sores can make eating and swallowing difficult. TBI may also cause dryness of the mouth, temporarily alter the taste of food, and/or cause thick saliva to form in the mouth and throat. Nausea and vomiting are common problems experienced by transplant patients. Nausea and vomiting may be caused by TBI, chemotherapy, and some medications. TBI, chemotherapy, infection, depression, and fatigue can cause a decrease in appetite and weight loss. Lack of appetite may continue to be a problem long after discharge from the hospital. Patients may also experience gastrointestinal problems such as diarrhea and constipation that could be caused by TBI, chemotherapy, gastrointestinal graft-versus-host disease, infection, and some medications. [25] [26]
Nutrition in cancer care embodies prevention of disease, treatment, cure, or supportive palliation. Caution should be exercised when considering alternative or unproven nutritional therapies during all phases of cancer treatment and supportive palliation, as these diets may prove harmful. Patient nutritional status plays an integral role in determining not only risk of developing cancer but also risk of therapy-related toxicity and medical outcomes. Whether the goal of cancer treatment is cure or palliation, early detection of nutritional problems and prompt intervention are essential.
The original principles of nutrition care for people diagnosed with cancer were developed in 1979 [1] and are still very relevant today. Proactive nutritional care can prevent or reduce the complications typically associated with the treatment of cancer. [1]
Many nutritional problems stem from local effects of the tumor. Tumors in the gastrointestinal tract, for example, can cause obstruction, nausea, vomiting, impaired digestion, and/or malabsorption. In addition to the effects of the tumor, marked alterations in normal metabolism of carbohydrates, protein, and/or fats can occur. [2]
The nutritional prognostic indicators most recognized as being predictive of poor outcome include weight loss, wasting, and malnutrition. In addition, significant weight loss at the time of diagnosis has been associated with decreased survival and reduced response to surgery, radiation therapy, and/or chemotherapy. [3]
Malnutrition and accompanying weight loss can be part of an individual’s presentation or can be caused or aggravated by treatments for the disease. Identification of nutrition problems and treatment of nutrition-related symptoms have been shown to stabilize or reverse weight loss in 50% to 88% of oncology patients. [4]
Screening and nutrition assessment should be interdisciplinary; the healthcare team (e.g., physicians, nurses, registered dietitians, social workers, psychologists) should all be involved in nutritional management throughout the continuum of cancer care. [5]
A number of screening and assessment tools are currently available for use in nutritional assessment. Examples of these tools include the Prognostic Nutrition Index, [6] [7] delayed hypersensitivity skin testing, institution-specific guidelines, and anthropometrics. Each of these tools can help identify persons at nutritional risk; unfortunately, the values obtained using such tools can be altered by the hydration status and the immune compromise frequently found in individuals diagnosed with cancer. In addition, each of these objective measures can carry a cost in terms of laboratory or practitioner time. One author has provided a useful overview of assessment procedures for advanced cancer patients. [8]
Another example of a screening and assessment procedure is the Patient-Generated Subjective Global Assessment (PG-SGA). Based on earlier work on a protocol called Subjective Global Assessment (SGA), [9] the PG-SGA is an easy-to-use and inexpensive approach in identifying individuals at nutritional risk and in triaging for subsequent medical nutritional therapy in a variety of clinical settings. [10] [11] The individual and/or caretaker complete sections on weight history, food intake, symptoms, and function. A member of the healthcare team evaluates weight loss, disease, and metabolic stress and performs a nutrition-related physical examination. A score is generated from the information collected. The need for nutrition intervention is determined according to the score.
Bioelectrical impedance analysis (BIA) is also used to assess nutritional status, as determined by body composition. [12] The BIA measures electrical resistance on the basis of lean body mass and body fat composition. Single BIA measures show body cell mass, extracellular tissue, and fat as a percent of ideal, whereas sequential measurements can be used to show body composition changes over time. Because of cost and accessibility, BIA is currently in limited use and often unavailable in most ambulatory settings.
Taste and smell defects are common in cancer patients and may affect nutritional status. The relative importance of chemosensory changes to the etiology of malnutrition was assessed in 66 patients with advanced cancer. Some degree of chemosensory abnormality was reported by 86% of patients; approximately one-half of patients reported interference with enjoying favorite foods. Poor appetite, nausea, early satiety, and chemosensory abnormalities presented concurrently. These findings were significantly related to decreased energy intake. Further research is required to design nutritional interventions for these chemosensory problems. [13]
Because nutritional status can quickly become compromised from illness and decreased dietary intake, and because nutritional well-being plays an important role in treatment and recovery from cancer, early screening and intervention as well as close monitoring and evaluation throughout all phases of cancer treatment and recovery are imperative in the pursuit of health for the individual with cancer.
Optimal nutritional status is an important goal in the management of individuals diagnosed with cancer. Although nutrition therapy recommendations may vary throughout the continuum of care, maintenance of adequate intake is important. Therefore, a waiver from most dietary restrictions observed during religious holidays is granted for those undergoing active treatment. Individuals with cancer are encouraged to speak to their religious leaders regarding this matter before a holiday.
Whether patients are undergoing active therapy, recovering from cancer therapy, or in remission and striving to avoid cancer recurrence, the benefit of optimal caloric and nutrient intake is well documented. [14] [15] [16]
The goals of nutrition therapy are to accomplish the following:
Patients with advanced cancer can receive nutritional support even when nutrition therapy can do little for weight gain. [17] [18] Such support may help accomplish the following:
In individuals with advanced cancer, the goal of nutrition therapy should not be weight gain or reversal of malnutrition, but rather comfort and symptom relief. [19]
Nutrition continues to play an integral role for individuals whose cancer has been cured or who are in remission. [20] A healthy diet helps prevent or control comorbidities such as heart disease, diabetes, and hypertension. Following a healthful nutrition program might help prevent another malignancy from developing.
As outlined above, individuals diagnosed with cancer are at risk for malnutrition resulting from the disease itself; from anticancer therapy such as surgery, radiation, or pharmacologic therapy; and/or from anorexia due to emotional turmoil. The following sections highlight the benefits, contraindications, methods of administration, and home care issues for all forms of nutrition support—oral, enteral, and parenteral.
The preferred method of nutrition support is via the oral route, with the use of dietary modifications to reduce the symptoms associated with cancer treatments. Enteral nutrition is indicated when the gastrointestinal (GI) tract is functional but oral intake is insufficient to meet nutritional requirements. Common situations in which enteral nutrition may be needed include malignancies of the head and neck regions, esophagus, and stomach. When the GI tract is dysfunctional, total parenteral nutrition (TPN) or enteral nutrition may be indicated; however, the widespread use of TPN is controversial because little evidence of improved survival has been demonstrated in patients with advanced cancer. [21] Parenteral nutrition has been shown to be beneficial in only a small group of patients—specifically, postoperative patients who are being aggressively treated and who have demonstrated a positive response rate. One study [22] reported that patients with GI cancer benefited from perioperative support with TPN, with one-third fewer complications and decreased mortality.
Optimal nutrition can improve the clinical course, outcome, and quality of life of patients undergoing treatment for cancer. [23] Virtually every cancer patient could benefit from consultation with a registered dietitian or physician to formulate a plan for nutrition and to begin meal planning. Oral nutrition, or eating by mouth, is the preferred method of feeding and should be used whenever possible. Appetite stimulants may be used to enhance the enjoyment of foods and to facilitate weight gain in the presence of significant anorexia. [24]
Recommendations during treatment may focus on eating foods that are high in energy, protein, and micronutrients to help maintain nutritional status. This may be especially true for individuals with early satiety, anorexia, and alteration in taste, xerostomia, mucositis, nausea, or diarrhea. Under most of these circumstances, eating frequently and including high-energy and high-protein snacks may help overall intake. [25]
At-risk individuals who may benefit from nutritional support might have one or more of the following characteristics: [26]
Although the many benefits of achieving good nutritional status via nutritional support can clearly be detailed, the disadvantages or questionable benefits of nutritional support must also be considered. The debate regarding the effect of nutritional support on tumor growth has not been settled; [27] though quality of life is usually improved with better nutritional status, the actual impact of nutritional support on longevity has yet to be definitively determined. [27]
Once the degree of malnutrition has been assessed, the decision to offer nutritional support and which form of support to utilize must be determined by the healthcare professional and other parties involved. Enteral and parenteral nutritional support offers viable options to reduce the risk of debilitating malnutrition and interruptions in anticancer therapy that may influence outcome. Each form of nutritional support has advantages and disadvantages. It is critical to thoroughly evaluate the diagnosis, prognosis, degree of malnutrition, function of the gut, and ease of delivery before embarking on the plan of nutritional support. Caution must also be exercised to avoid refeeding syndrome, the metabolic complication that is caused by rapid repletion of potassium, phosphorous, and magnesium in a severely malnourished or cachectic patient. [26]
The following sections highlight the benefits, contraindications, methods of administration, formulas, and home care issues for both enteral and parenteral nutrition.
The benefits of enteral nutrition, or tube feeding, are that it continues to use the gut, has fewer complications such as infection and organ malfunction, is often easier to administer, and is cheaper than parenteral nutrition. [26] [27] [28] [29] In addition, nutrients are metabolized and utilized more efficiently by the body.
Specific disease and condition-related indications for use consist of a diagnosis of a cancer of the alimentary canal (in particular, head and neck, esophageal, gastric, or pancreatic cancers) and severe complications/side effects from chemotherapy and/or radiation that are seriously jeopardizing the treatment plan of an individual already suffering from malnutrition. [26]
Contraindications for enteral nutritional support include a malfunctioning gastrointestinal tract, malabsorptive conditions, mechanical obstructions, severe bleeding, severe diarrhea, intractable vomiting, gastrointestinal fistulas in locations difficult to bypass with an enteral tube, inflammatory bowel processes such as prolonged ileus and severe enterocolitis, and/or an overall health prognosis not consistent with aggressive nutrition therapy. [26] Thrombocytopenia and general pancytopenic conditions following anticancer treatments may also prevent placement of an enteral tube.
Prospective Assessment
Several effective methods for the delivery of enteral nutritional support or tube feedings exist. An approximation of how long nutritional support will be needed is critical, however, to determine the most appropriate delivery route. Nasogastric, nasoduodenal, or nasojejunal methods are best for short-term support (<2 weeks). [29] The endpoint of delivery—the stomach, the duodenum, or jejunum—is determined by the risk of aspiration, with nasojejunal feeds recommended for individuals with aspiration risk. If the person with cancer is at very high risk for aspiration, enteral nutritional support may be contraindicated and parenteral nutrition should be considered. Also, immune-compromised individuals with mucositis, esophagitis, and/or herpetic, fungal, or candidiasis lesions in the mouth or throat may not be able to tolerate the presence of a nasogastrointestinal tube.
Tubes are constructed from silicone or polyurethane and can vary in length from 30 to 43 inches, with the shorter tubes used for nasogastric feedings. The diameters range from 5F to 16F catheters. Tubes may have weighted tips to help passage through the gut.
Percutaneous endoscopic gastrostomy tubes (PEGs) and percutaneous endoscopic jejunostomy tubes (PEJs) are generally used for long-term enteral feedings (>2 weeks). [29] The placement further down in the gastrointestinal tract has a number of advantages: the diameter of the tube is larger (15F-24F catheters), which allows easier and faster passage of formulas and medications; the risk for aspiration is lower because of the decreased chance of migration of the tube up into the esophagus; the risk for sinusitis or nasoesophageal erosion is lower; and this route is more convenient and aesthetically pleasing to the individual because of the ability to conceal the tube. [29] People anticipating long-term support may also consider a skin-level button gastrostomy or jejunostomy.
Assessment of need and ease of delivery are best done early. If the malnourished individual requires surgery for an unrelated event, a PEG or PEJ may be placed at that time to avoid an additional procedure.
Infusion Methods and Formulas
Enteral nutrition or tube feedings can be delivered at various rates. When possible, the bolus method is preferable because it mimics normal feeding, requires less time and equipment, and offers greater flexibility to the patient. [29] The following is a summary of infusion possibilities: [29]
After the infusion method has been determined, a formula needs to be selected. There are many formulas on the market, ranging from elemental preparations of predigested nutrients to more complete and complex formulas that mimic oral nutrition intake. Specialized formulas are available for specific health conditions such as diabetes mellitus and compromised renal function. Modular formulas that are not nutritionally complete but add specific nutrients such as protein, fat, and carbohydrate are also available. These preparations can be added to an existing formula to provide additional benefit.
Glutamine, an amino acid, is a key energy source for the gut and has been shown to help maintain gut health and integrity and to protect the gut from damage from radiation and chemotherapy. [29] [30] The use of supplemental glutamine in tube feedings in addition to L-arginine and omega-3 fatty acids is gaining popularity. These potentially beneficial nutrients are now available in formulas and as oral supplements. More research needs to be done, however, to thoroughly evaluate the benefits and possible disadvantages.
When a formula is being chosen, the institution nutrition formulary for available preparations, modular formulas, and additions such as glutamine or fiber should be considered. Consideration should also be given to the patient’s medical condition, gastrointestinal function, and financial resources.
Transition to Home
A significant number of patients using enteral nutritional support in the hospital are discharged to home while still on therapy. This can be done successfully and requires that the following conditions are met: [29]
Parenteral nutrition may be indicated in select individuals who are unable to use the oral or enteral route (i.e., those who have a nonfunctioning gut), such as those with obstruction, intractable nausea and/or vomiting, short-bowel syndrome, or ileus. Additional inclusive conditions common in the cancer population are severe diarrhea/malabsorption, severe mucositis or esophagitis, high-output gastrointestinal fistulas that cannot be bypassed by enteral intubation, and/or severe preoperative malnutrition. [27] [29]
Contraindications for use of parenteral nutrition are a functioning gut, a need for nutritional support for a duration less than 5 days, an inability to obtain intravenous (IV) access, and poor prognosis not warranting aggressive nutritional support. [27] [29] Additional conditions that should cause hesitation are the following: patient or caregiver does not want parenteral nutrition, patient is hemodynamically unstable or has profound metabolic and/or electrolyte disturbances, and/or patient is anuric without dialysis. [27] [29]
Prospective Assessment
If parenteral nutrition is determined to be beneficial, the two venous access sites are central and peripheral. Cancer patients usually have central IV catheters to accommodate multiple IV therapies. If this is not the case, a peripheral catheter can be placed, although care must be taken to avoid overuse of the peripheral accesses with nutritional support and anticancer therapies. Numerous peripheral infusions and venesections can result in vessel sclerosis. The following discussion highlights both types of access: [27] [29]
Solutions
Parenteral nutrition formulas are tailored to individual clinical status and nutritional needs. The formulas contain a combination of amino acids, dextrose, lipids, vitamins, minerals and trace elements, fluids, electrolytes, and, possibly, additives such as insulin, heparin, and antacids.
Solutions running through peripherally placed lines must be altered by reducing the percentage of calories from carbohydrates (hypertonic) and increasing the percentage from lipids (isotonic). Peripheral solutions with a final dextrose concentration lower than 10% and an osmolarity lower than 900 mOsm/kg are generally well tolerated. [27] The mandatory alteration in macronutrients can present problems with delivery of recommended calories/nutrients.
Central infusions are not limited by osmolarity because they use a large vein; this feature makes central venous access a good choice for severely stressed, hypermetabolic individuals and/or individuals requiring a fluids restriction. [27]
Many drugs and compounds are not compatible with parenteral solutions and should not be added to the solutions or even run through parenteral solution-designated lines to avoid the chance of interaction or precipitation. Pharmacists should be consulted in the preparation of parenteral nutrition solutions and before any additional medications or compounds are added.
Complications
Incompatibility with drugs is just one of a number of possible complications associated with parenteral nutrition administration. Complications can be categorized as mechanical (vein thrombosis, pneumothorax, and catheter tip misplacement) or metabolic (hyperglycemia/hypoglycemia, hypokalemia, and elevated liver function tests). [27] Because of the precision that is required to order, administer, and maintain this type of support, trained and experienced medical personnel should be involved. Many facilities have dedicated nutritional support multidisciplinary teams.
Transition to Home
Cancer is one of the most common diagnoses among home parenteral nutrition recipients. The following criteria should be used when assessing the appropriateness of discharge to home on parenteral feeds. The individual must meet the following conditions: [27]
Tapering off parenteral nutritional support requires coordination between the medical staff and the patient. Because parenteral support is given continuously, the taper involves a gradual reduction in rate and time. Parenteral nutritional support cannot be abruptly discontinued.
When transitioning to enteral feeds, parenteral support can be decreased to 50% when enteral feeds reach 33% to 50% of the goal rate; it can be discontinued when enteral feeds reach 75% of goal and are tolerated. [27]
When transitioning to oral nutrition, parenteral solutions can be decreased to 50% when the patient is tolerating a full liquid diet or beyond and can be discontinued once solid foods are tolerated in addition to the consumption of adequate fluids. [27]
Both enteral and parenteral nutritional support can be safe and effectively used to help reverse the effects of malnutrition in individuals with cancer. However, nutritional support, particularly parenteral support, is still controversial when used as routine adjuvant therapy to anticancer therapies or when there is an absence of efficacious cancer treatment. [31] Every measure should be employed to sustain an individual and improve his or her condition through oral intake before consideration is given to nutritional support.
Side effects of cancer treatments vary from patient to patient, depending on the type, length, and dose of treatments as well as the type of cancer being treated. This section offers practical suggestions for managing the common symptoms affecting nutrition intake.
Recommendations during treatment may focus on eating foods that are high in energy, protein, and micronutrients to help maintain nutritional status. This may be especially true for individuals with early satiety, anorexia, and alteration in taste, xerostomia, mucositis, nausea, or diarrhea. Under most of these circumstances, eating frequently and including high-energy and high-protein snacks may help overall intake. [25]
Loss of appetite or poor appetite is one of the most common problems that occurs with cancer and its treatment. [32] The cause of anorexia may be multifactorial. Treatment modality, the cancer itself, and psychosocial factors may all play a role in appetite. [32] Eating frequent meals and snacks that are easy to prepare may be helpful. Liquid supplements may improve total energy intake and body function [33] and may work well when eating solids is difficult. Other liquids that contain energy may also help, such as juices, soups, milk, shakes, and fruit smoothies. Eating in a calm, comfortable environment and exercising regularly may also improve appetite. [32]
Suggestions for appetite improvement include the following: [34] [35] [36]
What types of foods are usually recommended?
See the NCI Web site Eating Hints for Cancer Patients: Before, During, and After Treatment for recipes such as Lactose-Free Double Chocolate Pudding, Banana Milkshake, and Fruit and Cream. For a free copy of this booklet, call the Cancer Information Service at 1-800-4-CANCER (1-800-422-6237).
Alterations in taste can be related to unknown effects of cancer, radiation treatment, dental problems, mucositis and infection (thrush), or medications. Cancer patients undergoing chemotherapy frequently report changes in their sense of taste, specifically a bitter taste sensation during administration of the cytotoxic drugs. [37] One study measured the taste thresholds among cancer patients under chemotherapy compared with controls. [38] In this study, 62% of patients complained of taste disorders associated with the chemotherapy medications. Taste dysfunction can result in food avoidance, inducing weight loss and anorexia, all of which can have significant consequences on patients' quality of life. Simply changing the types of foods eaten as well as adding additional spices or flavorings to foods may help. Citrus may be tolerated well if no mouth sores or mucositis is present. Rinsing the mouth before eating may help improve the taste of food. [32]
While undergoing cancer therapy, patients may experience taste changes or develop sudden dislikes for certain foods. Their sense of taste may return partially or completely, but it may be a year after therapy ends before their sense of taste is normal again. A randomized clinical trial found that zinc sulfate during treatment may be helpful in expediting the return of taste after head and neck irradiation. [39]
Suggestions for helping cancer patients manage taste changes include the following:
Xerostomia (dry mouth) is most commonly caused by radiation therapy that is directed at the head and neck. [35] A number of medications may also induce xerostomia. Dry mouth may affect speech, taste sensation, ability to swallow, and use of oral prostheses. There is also an increased risk of cavities and periodontal disease because less saliva is produced to cleanse the teeth and gums.
A primary method of coping with xerostomia is to drink plenty of liquids (25–30 mL/kg per day) and eat moist foods with extra sauces, gravies, butter, or margarine. [25] [36] [40] In addition, hard candy, frozen desserts such as frozen grapes, chewing gum, flavored ice pops, and ice chips may be helpful. [32] Oral care is very important to help prevent infections. Irradiation to the head and neck of a patient who has permanent dry mouth symptoms may result in reduced intake of energy, iron, zinc, selenium, and other key nutrients. [41] Special efforts should be made to help tailor meals and snacks for individuals with xerostomia.
Suggestions for lessening or alleviating dry mouth include the following: [36]
(Refer to the PDQ summary on Oral Complications of Chemotherapy and Head/Neck Radiation for more information on xerostomia.)
Stomatitis, or a sore mouth, can occur when cells inside the mouth, which grow and divide rapidly, are damaged by treatment such as bone marrow transplantation, chemotherapy, and radiation therapy. These treatments may also affect rapidly dividing cells in the bone marrow, which may make patients more susceptible to infection and bleeding in their mouth. By carefully choosing foods and by taking good care of their mouths, patients can usually make eating easier. [42] [43] [44] Individuals who have mucositis, mouth sores, or tender gums should eat foods that are soft, easy to chew and swallow, and nonirritating. [32] Some conditions may require processing foods in a blender. Irritants may include acidic, spicy, salty, and coarse-textured foods. A pilot study found that oral glutamine swishes might be helpful in reducing the duration and severity of mucositis. [45] Glutamine may also reduce the duration and severity of stomatitis during cytotoxic chemotherapy. [45] [46]
Suggestions for people with cancer who are experiencing stomatitis include the following:
(Refer to the PDQ summary on Oral Complications of Chemotherapy and Head/Neck Radiation for more information on mucositis.)
Nausea can affect the amount and types of food eaten during treatment. Eating before treatment is important, as well as finding foods that do not trigger nausea. Frequent triggers for nausea include spicy foods, greasy foods, or foods that have strong odors. [32] Once again, frequent eating, and slowly sipping on fluids throughout the day may help.
Additional eating suggestions include the following: [19]
(Refer to the PDQ summary on Nausea and Vomiting for further information.)
Radiation, chemotherapy, gastrointestinal surgery, or emotional distress can result in diarrhea. Avoiding hyponatremia, hypokalemia, and dehydration during episodes of diarrhea requires the intake of additional oral fluids and electrolytes. Broth, soups, sports drinks, bananas, and canned fruits may be helpful for the replenishment of electrolytes. Diarrhea may worsen with greasy foods, hot or cold liquids, or caffeine. [32] In the presence of radiation enteritis, fibrous foods—especially dried beans and cruciferous vegetables—may contribute to frequent stools. [47] Meal planning should be individualized to meet nutritional needs and tolerances. Oral glutamine may also help prevent intestinal toxicity from fluorouracil. [48]
Additional suggestions include the following: [19]
(Refer to the PDQ summary on Gastrointestinal Complications for more information on diarrhea.)
People with cancer may have a low white blood cell count for a variety of reasons, some of which include radiation therapy, chemotherapy, or the cancer itself. Patients who have a low white blood cell count are at an increased risk for developing an infection. [49] Suggestions for helping people prevent infections related to neutropenia include the following:
This list may be modified after chemotherapy or when blood count returns to normal.
Hot flashes, typically associated with postmenopausal states in women without cancer, occur in two thirds of women with a history of breast cancer and three quarters of men with locally advanced or metastatic prostate cancer. Estrogen replacement controls hot flashes in postmenopausal women but may be contraindicated in patients with hormone-responsive tumors or other medical conditions. In May 2002, the Women's Health Initiative, a large randomized placebo-controlled trial of the risks and benefits of estrogen plus progestin in healthy postmenopausal women, was stopped prematurely at a mean follow-up of 5.2 years (± 1.3) because of the detection of a 1.26-fold increased breast cancer risk (95% confidence interval, 1.00–1.59) in women receiving hormone replacement therapy. Tumors among women in the hormone replacement therapy group were slightly larger and more advanced than those in the placebo group, with a substantial and statistically significant rise in the percentage of abnormal mammograms at first annual screening; such a rise might hinder breast cancer diagnosis and account for the later stage at diagnosis. [50] [51] Dietary soy phytoestrogens have been proposed for hot flash control in individuals for whom estrogen is contraindicated; however, the risk of soy phytoestrogen use on breast cancer recurrence and/or progression has not yet been clarified. Soy phytoestrogens are weak estrogens found in plant foods. In vitro models suggest that these compounds have a biphasic effect on mammary cell proliferation that is dependent on intracellular concentrations of phytoestrogens and estradiol. [52] Risk in vivo has not been clarified; however, two randomized placebo-controlled trials in breast cancer survivors show no benefit of soy over placebo in alleviating hot flashes. [53] [54] (Refer to the PDQ summary on Fever, Sweats, and Hot Flashes for more information.)
Adequate hydration is critically important for health maintenance. There are several common scenarios found in cancer treatment that may lead to altered hydration status and electrolyte imbalance. Hydration status can become compromised with prolonged disease or treatment-related diarrhea and/or episodes of nausea and vomiting. [55] Acute and chronic pain can also adversely affect the appetite and hence the desire to eat and drink. Fatigue, an all-too-common complaint of people with cancer, can be one of the first signs of dehydration. [56] Once the underlying cause for altered hydration is appropriately managed, some suggestions to promote adequate hydration include the following: [32] [57] [58]
Constipation is defined as fewer than three bowel movements per week. [59] It is a very common problem among individuals with cancer and may result from lack of adequate fluids or dehydration, lack of fiber in the diet, physical inactivity or immobility, anticancer therapies such as chemotherapy, and medications used in the treatment of side effects of anticancer therapy such as antiemetics and opioids. [59] [60] In addition, commonly used pharmacologic agents such as minerals (calcium, iron), nonsteroidal anti-inflammatory drugs, and antihypertensives can cause constipation. [59]
An effective bowel regimen should be in place before the problem of constipation occurs. Preventive measures should be common practice, and special attention should be paid to the possibility of constipation as a side effect of certain therapies. Suggestions include the following: [57] [59]
If prevention does not work and constipation is a problem, the application of a three-pronged approach for treatment is suggested: diet (fiber and fluids), physical activity, and over-the-counter or prescription medication. The use of biofeedback or surgery may also be considered. [61]
Suggestions are as follows: [57] [59] [62] [61] [15]
Good sources of fiber include the following: [19] [57]
*These food items may cause gas; products containing alpha-galactosidase enzyme may be helpful.
Advanced cancer is often associated with cachexia. [1] [2] [3] [4] Individuals diagnosed with cancer may develop new, or worsening, nutrition-related side effects as cancer becomes more advanced. The most prevalent symptoms in this population are the following: [1] [2] [3]
As defined by the World Health Organization, palliative care is an approach that improves the quality of life of patients and their families facing the problems associated with life-threatening illness, through the prevention and relief of suffering by means of early identification and impeccable assessment and treatment of pain and other problems, physical, psychosocial, and spiritual. The goal of palliative care is to give relief of symptoms that are bothersome to the patient. Although some of the symptoms listed above can be effectively treated, anorexia, though common, is a symptom that is often not noted as problematic for most terminally ill patients but is distressing to most family members; this distress may vary according to cultural factors. Several studies have demonstrated that terminally ill patients lack hunger, and of those who did experience hunger, the symptom was relieved with small amounts of oral intake. [5]
Decreased intake, especially of solid foods, is common as death becomes imminent. Individuals usually prefer and tolerate soft-moist foods and refreshing liquids (full and clear liquids). Those who have increased difficulty swallowing have less incidence of aspiration with thick liquids than with thin liquids.
Dietary restriction is not usually necessary, as intake of prohibited foods (e.g., sweets in the diabetic patient) is insufficient to be of concern. [6] As always, food should continue to be treated and viewed as a source of enjoyment and pleasure. Eating should not just be about calories, protein, and other macronutrient and micronutrient needs.
Diet restrictions are sometimes appropriate, however. [6] [7] For example, people with pancreatic cancer, gynecologic cancer, abdominal carcinomatosis, pelvic masses, or retroperitoneal lymph node masses may have bowel obstruction less frequently when adhering to a prophylactic soft diet (i.e., no raw fruits and vegetables, no nuts, no skins, no seeds). Any restriction should be considered in terms of quality of life and the patient’s wishes.
Decisions regarding nutritional support should be made with the following considerations:
The benefit of home parenteral nutrition in patients with advanced cancer is often debated, and evidence-based data regarding its use are lacking. For patients who still have good quality of life but also have mechanical or physiologic barriers to achieving adequate nourishment and hydration orally (e.g., head and neck cancer), prolonged survival may be achieved with the use of enteral or parenteral nutrition. [5] In a qualitative study, 13 patients and 11 family members perceived some benefits with home parenteral nutrition. [8] The most salient positive feature of home parenteral nutrition was a sense of relief and security that nutritional needs were met. In this study, patients were also able to take oral nutrition, and the administration of total parenteral nutrition was often described as a complement to the patients' oral intake. This contradicts the traditional indication for TPN, i.e., that its use be reserved for times when nourishment via the gastrointestinal tract is not possible. Patients in this study also had regular visits by home health care providers, which could have had a positive impact on their physical, social, and psychological well-being.
Although most patients with advanced cancer will not benefit from artificial nutrition, for someone who still has good quality of life but also has mechanical or physiologic barriers to achieving adequate nourishment and hydration orally (e.g., head and neck cancer), prolonged survival can be achieved with the use of enteral or parenteral nutrition. [5]
All people with cancer and their caregivers have the right to make informed decisions. The healthcare team, with guidance from the registered dietitian, should inform patients and their caregivers about the pros and cons of using nutritional support in advanced disease. Despite the lack of proven benefit, artificial nutrition at the end of life will remain a sensitive topic for some patients and families. [5] In most cases, the cons outweigh the pros. The following is a list of the pros and cons of using nutritional support in advanced disease: [6] [7] [9]
Individuals being treated for cancer may require the use of a series of curative or supportive drugs throughout their care; they may also receive advice on the use of dietary supplements, or they may self-diagnose and self-prescribe the use of dietary supplements. Drug-nutrient interactions or dietary supplement-drug-nutrient interactions can occur and can compromise the safety and efficacy of the anticancer treatment plan. A review of antineoplastic drugs listed in various references revealed the interactions listed in Table 2. [10]
| Trade Name | Generic Name | Food Interactions |
|---|---|---|
| Targretin | bexarotene | Grapefruit juice may increase drug concentration and toxicities. |
| Folex | methotrexate | Alcohol may increase hepatotoxicity. |
| Rheumatrex | ||
| Mithracin | plicamycin | Supplements containing calcium and vitamin D may decrease effect. |
| Matulane | procarbazine | This chemotherapy is a mild MAOI; a low-tyramine diet should be followed. |
| Temodar | temozolomide | Food may decrease drug rate and absorption. |
| MAOI = monoamine oxidase inhibitor. | ||
Table 3 provides information about known interactions with dietary supplements—in this case, herbs—commonly consumed by individuals with cancer. Of note, the information provided covers only known interactions; additional side effects are possible for these herbs. [11] A pharmacist or updated dietary supplement references should be consulted for more information.
| Herbal | Possible Food/Drug Interactions |
|---|---|
| Black cohosh | May further reduce lipids or blood pressure when combined with prescription medications; may increase antiproliferative effect obtained with tamoxifen. |
| Chamomile | May increase bleeding when used with anticoagulants; may increase sedative effect of benzodiazepines. |
| Dong quai | May increase effects of warfarin. |
| Echinacea | May interfere with immunosuppressive therapy. |
| Garlic | May increase bleeding time with aspirin, dipyridamole, and warfarin; may increase effects and adverse effects of hyperglycemic agents. |
| Ginkgo biloba | May increase bleeding time with aspirin, dipyridamole, and warfarin; may increase blood pressure when used with thiazide diuretics. |
| Ginseng | May adversely affect platelet adhesiveness/blood coagulation; may increase hypoglycemia with insulin; may interfere with antipsychotic drugs; may cause hypertension when used long-term with caffeine. |
| Kava kava | May increase central nervous system depression when used with alcohol and sedatives; may cause hepatotoxicity. [12] |
| St. John's wort | May cause serotonin syndrome when used with antidepressants and drugs using p450 microsomal enzyme for metabolism. [13] Interacts with procarbazine. |
| Ma huang (ephedra) | Increases toxicity with beta-blockers, MAOIs, caffeine, and St. John’s wort. |
| Yohimbe | Decreases effect of antidepressants, antihypertensives, hyperglycemic agents, MAOIs, and St. John’s wort. |
| MAOIs = monoamine oxidase inhibitors. | |
Numerous studies have shown that dietary practices can either promote health or have deleterious effects. [14] [15] [16] Health agencies and disease prevention organizations used the resulting evidence to develop dietary recommendations for the public. Created for healthy individuals, these guidelines can be modified by healthcare providers to focus on specific medical conditions. Individuals diagnosed with cancer can benefit during and after treatment by following these to the best of their ability.
The United States Department of Agriculture (USDA) developed the most commonly used set of guidelines, the Dietary Guidelines for Americans, [17] to be used in conjunction with the Food Guide Pyramid. These guidelines feature recommendations that support good overall health, including fitness guidelines as well as suggestions about what to emphasize and limit in the diet. The Food Guide Pyramid depicts the five food groups: grains, vegetables, fruits, dairy, and meat and nonmeat protein (fats, oils, and sweets to be used sparingly), each accompanied by the amount of servings needed to provide adequate nutrients and calories daily.
Key recommendations in the 2005 version of Dietary Guidelines for Americans include the following:
The American Cancer Society (ACS) Guidelines for Nutrition and Cancer Prevention [18] first published in 1996 provide more detailed dietary advice with a focus on cancer prevention. These guidelines, updated in 1999, are consistent in principle with those recommended by the USDA and other organizations. The ACS guidelines form the beginning of a report that contains the most up-to-date information available on nutrition issues linked to neoplastic diseases. Included are in-depth answers on how different foods, food preparation methods, portion sizes, variety, and overall calories can reduce or increase the risk of specific cancers. These guidelines provide sound advice regarding healthy eating for cancer prevention for all individuals, including cancer survivors. [19]
The ACS guidelines include the following:
The American Institute for Cancer Research (AICR) published a report in 1997 [20] that includes an expert scientist panel review and evaluation of more than 4,500 studies on diet and cancer. The AICR Diet and Health Guidelines for Cancer Prevention were developed from these recommendations. The AICR also maintains a Web site that includes booklets of healthy recipes that follow their dietary guidelines. [21] The AICR and ACS guidelines are similar.
The AICR guidelines include the following:
The importance of maintaining healthy eating patterns extends through the continuum of care to the prevention of secondary cancers. Although dietary recommendations do not provide specific guidelines for secondary cancer prevention, it is generally accepted that individuals posttreatment should follow cancer prevention dietary recommendations established for the general population.
Consumption of more than five servings per day of fruits and vegetables is generally associated with a reduced risk of lung cancer. [22] [23] [24] [25] [26] [27] [28] [29] [30] Early studies of beta-carotene supplementation in men who smoked, however, showed increased risk. [31] It is now known that more than 500 types of carotenoids—including alpha-carotene, beta-cryptoxanthin, lutein, and lycopene—are present in foods. Multiple components in fruits and vegetables, such as isothiocyanates, carotenoids, and vitamin C, may explain the reduction in lung cancer risk.
Saturated fat and intake of meat or animal fat has been associated with increased risk of advanced prostate cancer in several epidemiologic studies. [32] In one study, men given test diets high in animal fat were shown to have higher free androgen index and testosterone levels postprandially than those given a diet low in animal fat. [33] This may provide some insight into the association between prostate cancer risk and diet.
Diet and risk of prostate cancer progression was evaluated in more than 1,200 men who participated in the Health Professionals Follow-up Study. Results support the hypothesis that postdiagnostic diet can influence disease progression in men diagnosed with localized or regional prostate cancer. Preliminary results of diet assessments after prostate cancer diagnosis suggest that a diet high in tomato sauce and fish may offer meaningful protection against disease progression. These findings are consistent with other studies that have reported the potential benefits of lycopene consumption and reduced risk of developing prostate cancer. Tomato sauce is the best source of bioavailable lycopene. The association of fish intake with lower risk of prostate cancer recurrence or progression is also consistent with previous results from cancer prevention studies that reported positive benefits associated with higher fish and fish oil intake. The current results suggest that diet modifications after diagnosis may have similar beneficial effects on protecting against the risk of prostate cancer progression, as has been shown in previous studies. [34] [35]
The Alpha-Tocopherol Beta-Carotene Cancer Prevention Study, a randomized trial (n = 29,133), found that daily supplementation with 50 mg of alpha-tocopherol was associated with a 41% reduction in prostate cancer mortality. [36] Daily supplementation with 20 mg of beta-carotene, however, was associated with a 23% increased incidence of prostate cancer in smokers.
Recurrence of breast cancer and its relationship to diet have been examined in prospective cohort studies. [37] [38] [39] In one study, total energy and saturated and monounsaturated fat were associated with an increased risk of recurrence, although the association with the various types of fat was weakened after adjusting for energy intake. [37] When comparing the dietary intake of breast cancer survivors in Hispanic versus non-Hispanic white women, one study found more similarities than differences. [40]
Obesity and low physical activity have each been associated with increased breast cancer risk in postmenopausal women. Higher fasting insulin levels, the result of obesity and lower physical activity, have been proposed as a potential mediator of this increase in risk. [41] To help determine the effects of physical activity on survival rates, a prospective observational review was conducted in which women diagnosed with stage I, II, or III breast cancer were followed postdiagnosis through the Nurses' Health Study. The study found that a moderate increase in physical activity was associated with reduced risk of disease recurrence and increased survival rates, with the greatest benefit occurring in women who performed the equivalent of walking 3 to 5 hours per week at an average pace. [42] Another prospective observational study using data from more than 5,000 women diagnosed with nonmetastatic breast cancer who participated in the Nurses' Health Study suggests that high body mass index (BMI) before diagnosis is associated with poorer survival rates. Higher rates of breast cancer recurrences and mortality were also observed in women with an increase in BMI of 0.5 kg/m2 or more one year or more after diagnosis, particularly in premenopausal, nonsmoking women. [43] Strategies to reduce body weight by increasing physical activity and decreasing caloric intake resulting in reduced insulin levels may lead to a reduction in breast cancer risk or risk of recurrence. [41]
The use of soy foods in breast cancer survivors has led to significant research in this area. Several studies suggest soy consumption may reduce breast cancer risk and improve survival; however, the estrogenic effects of isoflavones naturally found in soy products have led to controversy among health professionals over the use of soy by breast cancer patients, especially those with estrogen receptor–positive tumors. Research on genistein and daidzein, the two main isoflavones in soy, has shown that these phytochemicals may bind to estrogen receptors and decrease the plasma estrogen levels in women, thus acting in a preventive manner. [44] Animal studies, however, have found that genistein inhibited the efficacy of tamoxifen, a drug used to block the body’s circulating estrogen. [45] One study [46] reviewed the relevant literature and found no convincing data to support the claim that soy is protective against breast cancer or that soy is harmful for women with a history of, or at high risk for, breast cancer. A follow-up study using data collected from a large cohort of breast cancer patients as part of the Shanghai Breast Cancer Study also concluded that soyfoods do not have an adverse effect on breast cancer survival. [47]
Researchers from these studies concluded that soyfoods, as part of a healthy diet and in moderate amounts, are safe to consume; however, there is not enough evidence to recommend that breast cancer patients begin to consume soy specifically to prevent the occurrence of a secondary tumor and enhance survival. [44] Adding soy to the diet after a diagnosis of breast cancer has not been shown to be protective against recurrences. Likewise, the consumption of concentrated isolated isoflavone supplements in the form of powders or pills has not shown effects consistent with breast cancer risk reduction and is not recommended. [46] [48] As more research is conducted on the biological mechanisms relating to soy isoflavone intake, scientists may clarify the optimal exposure, duration, and timing of intake. Recommendations for the inclusion of soy in the diets of breast cancer survivors should be based on all available (and the most current) evidence. [49]
In a prospective study, breast cancer recurrence and mortality were strongly associated with beer consumption. [38] There appears to be an association between the consumption of two or more alcoholic drinks per day and an increased risk of breast cancer. [50] Dietary folate may attenuate the risks of postmenopausal breast cancer associated with family history, but only if alcohol use is avoided or minimized. In a study of 33,552 postmenopausal women aged 55 to 69 years, women with a family history of breast cancer who did not drink alcohol and who had adequate amounts of dietary folate demonstrated rates of breast cancer similar to those in women with no family history. [51]
Dietary fiber intake and its relationship to reduced cancer risk is more complex than once thought. [52] Supplementation studies of wheat bran fiber did not show an effect on the recurrence of adenomas, but the duration of supplementation (36–48 weeks) may not have been long enough. [52] In other words, the benefits from whole grains may only be seen on long-term intake. For example, the Iowa Women’s Health Study found that dietary fiber from all sources was associated with a 20% reduced risk of colon cancer. [53] Supplementation with 13.5 g of wheat fiber per day reduced the fecal concentration of bile acids by 52% and reduced the concentration of deoxycholic acid by 48%. [54] It is also known that dietary fiber decreases gastrointestinal transit time, thereby decreasing the time during which toxins persist in the gut. [55]
A population-based case-control study in Sweden found that intake of cereal fiber was associated with a 77% reduction in risk of gastric cardia cancer (relative risk = 0.3; 95% confidence interval, 0.2–0.5). [56] Wheat fiber may be a scavenger of nitrites under acidic conditions. [57]
Another case control study found that high antioxidant intake (total median intake of vitamin C [88 mg/day], alpha-tocopherol [6.8 μg/day], and beta-carotene [5 mg/day]) was associated with a 50% reduced risk of adenocarcinoma and a 40% reduced risk of squamous cell carcinoma of the esophagus, but risk of gastric cardia adenocarcinoma was not reduced. [58] Beta-carotene and total antioxidants were associated with a reduced risk of adenocarcinoma of the esophagus when reflux symptoms were present. Recall bias likely was a factor in this study, but the diverging effects antioxidants appear to have on histologic types of esophageal cancer suggest that the patterns of intake have been fairly consistent.
The American Cancer Society’s Healthy Eating Cookbook: a Celebration of Food, Friends, and Healthy Living. 3rd ed. Atlanta, Ga: The American Cancer Society, 2005.
Bloch A, Cassileth BR, Holmes MD, Thomson CA, eds.: Eating Well, Staying Well During and After Cancer. Atlanta, GA: American Cancer Society, 2004.
Eldridge B, Hamilton K: Management of Nutrition Impact Symptoms in Cancer and Educational Handouts. Chicago, Ill: The American Dietetic Association, 2004.
Ghosh K, Carson L, and Cohen E: Betty Crocker’s Living With Cancer Cookbook: Easy Recipes and Tips Through Treatment and Beyond. New York, NY: Hungry Minds, 2002.
Kogut VJ, Luthringer SL, eds.: Nutritional Issues In Cancer Care. Pittsburgh, Pa: The Oncology Nursing Society, 2005.
McCallum PD, Polisena CG, eds.: The Clinical Guide to Oncology Nutrition. Chicago, Ill: The American Dietetic Association, 2000.
Weihofen DL, Robbins J, Sullivan PA: Easy-To-Swallow, Easy-To-Chew Cookbook: Over 150 Tasty and Nutritious Recipes for People Who Have Difficulty Swallowing. New York, NY: John Wiley & Sons, Inc., 2002.
Wilson JR: I-Can’t-Chew Cookbook: Delicious Soft-Diet Recipes for People With Chewing, Swallowing, or Dry-Mouth Disorders. Alameda, Calif: Hunter House Inc., 2003.
Check NCI’s PDQ Cancer Clinical Trials Registry for U.S. supportive and palliative care trials about malnutrition, nutritional support and nutritional therapy that are now accepting participants. The list of trials can be further narrowed by location, drug, intervention, and other criteria.
General information about clinical trials is also available from the NCI Web site.
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