Tumors of low malignant potential (i.e., borderline tumors) account for 15% of all epithelial ovarian cancers. Nearly 75% of these tumors are stage I at the time of diagnosis. These tumors must be recognized because their prognosis and treatment is clearly different from the frankly malignant invasive carcinomas.
A review of 22 series (953 patients) with a mean follow-up of 7 years revealed a survival rate of 92% for patients with advanced-stage tumors, if patients with so-called invasive implants were excluded. The cause of death was determined to be benign complications of disease (e.g., small bowel obstruction), complications of therapy, and only rarely (0.7%), malignant transformation.  In one series, the 5-, 10-, 15-, and 20-year survival rates of patients with low malignant potential tumors (all stages), as demonstrated by clinical life table analysis, were 97%, 95%, 92%, and 89%, respectively.  In this series, mortality was stage dependent: 0.7%, 4.2%, and 26.8% of patients with stages I, II, and III, respectively, died of disease.  Another large study showed early stage, serous histology, and younger age to be associated with a more favorable prognosis.  In contrast to the excellent survival rates for early-stage disease reported above, the Federation Internationale de Gynecologie et d’Obstetrique Annual Report (#21) included 529 patients with stage I tumors with a 5-year actuarial survival rate of 89.1%. Similarly, good survival was found in a large prospective study.  Nonetheless, these survival rates are clearly in contrast with the 30% survival rate for invasive tumors (all stages).
The less common endometrioid tumor of low malignant potential should not be regarded as malignant because it seldom, if ever, metastasizes. Malignant transformation can, however, occur and may be associated with a similar tumor outside of the ovary; such tumors are the result of either a second primary or rupture of the primary endometrial tumor. 
The Féderation Internationale de Gynécologie et d’Obstétrique (FIGO) and the American Joint Committee on Cancer (AJCC) have designated staging to define ovarian low malignant potential tumors; the FIGO system is most commonly used.  
|I||Growth limited to the ovaries.|
|Ia||Growth limited to one ovary; no ascites present containing malignant cells. No tumor on the external surface; capsule intact.|
|Ib||Growth limited to both ovaries; no ascites present containing malignant cells. No tumor on the external surfaces; capsules intact.|
|Icb||Tumor either stage Ia or Ib, but with tumor on surface of one or both ovaries, or with capsule ruptured, or with ascites present containing malignant cells, or with positive peritoneal washings.|
|II||Growth involving one or both ovaries with pelvic extension.|
|IIa||Extension and/or metastases to the uterus and/or tubes.|
|IIb||Extension to other pelvic tissues.|
|IIcb||Tumor either stage IIa or IIb, but with tumor on surface of one or both ovaries, or with capsule(s) ruptured, or with ascites present containing malignant cells, or with positive peritoneal washings.|
|III||Tumor involving one or both ovaries with histologically confirmed peritoneal implants outside the pelvis and/or positive regional lymph nodes. Superficial liver metastases equals stage III. Tumor is limited to the true pelvis, but with histologically proven malignant extension to small bowel or omentum.|
|IIIa||Tumor grossly limited to the true pelvis, with negative nodes, but with histologically confirmed microscopic seeding of abdominal peritoneal surfaces, or histologic proven extension to small bowel or mesentery.|
|IIIb||Tumor of one or both ovaries with histologically confirmed implants, peritoneal metastasis of abdominal peritoneal surfaces, none exceeding 2 cm in diameter; nodes are negative.|
|IIIc||Peritoneal metastasis beyond the pelvis >2 cm in diameter and/or positive regional lymph nodes.|
|IV||Growth involving one or both ovaries with distant metastases. If pleural effusion is present, there must be positive cytology to allot a case to stage IV. Parenchymal liver metastasis equals stage IV.|
|aAdapted from FIGO Committee on Gynecologic Oncology. |
|bIn order to evaluate the impact on prognosis of the different criteria for allotting cases to stage Ic or IIc, it would be of value to know if rupture of the capsule was spontaneous, or caused by the surgeon; and if the source of malignant cells detected was peritoneal washings, or ascites.|
The value of complete staging has not been demonstrated for early-stage cases, but the opposite ovary should be carefully evaluated for evidence of bilateral disease. Although the impact of surgical staging on therapeutic management is not defined, in a study, 7 of 27 patients with presumed localized disease were upstaged following complete surgical staging.  In two other studies, 16% and 18% of patients with presumed localized tumors of low malignant potential were upstaged as a result of a staging laparotomy.   In one of these studies, the yield for serous tumors was 30.8% compared with 0% for mucinous tumors.  In another study, patients with localized intraperitoneal disease and negative lymph nodes had a low incidence of recurrence (5%), whereas patients with localized intraperitoneal disease and positive lymph nodes had a statistically significantly higher incidence of recurrence (50%). 
In early-stage disease (stage I or II), no additional treatment is indicated for a completely resected tumor of low malignant potential.  When a patient wishes to retain childbearing potential, a unilateral salpingo-oophorectomy is adequate therapy.   In the presence of bilateral ovarian cystic neoplasms, or a single ovary, a partial oophorectomy can be employed when fertility is desired by the patient.  Some physicians stress the importance of limiting ovarian cystectomy to stage IA patients in whom the margins of the cystectomy specimens are free of tumor.  In a large series, the relapse rate was higher with more conservative surgery (cystectomy > unilateral oophorectomy > TAH, BSO); differences, however, were not statistically significant, and survival was nearly 100% for all groups.   When childbearing is not a consideration, a total abdominal hysterectomy and bilateral salpingo-oophorectomy is appropriate therapy. Once a woman has completed her family, most, but not all,  physicians favor removal of remaining ovarian tissue as it is at risk of recurrence of a borderline tumor, or even rarely, a carcinoma.  
Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with stage I borderline ovarian surface epithelial-stromal tumor and stage II borderline ovarian surface epithelial-stromal tumor. The list of clinical 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.
Patients with advanced disease should undergo a total hysterectomy, bilateral salpingo-oophorectomy, omentectomy, node sampling, and aggressive cytoreductive surgery. Patients with stage III or IV disease with no gross residual tumor have had a 100% survival rate in some series regardless of the follow-up duration.   The 7-year survival rate of patients with gross residual disease was only 69% in a large series  and appears to be inversely proportional to the length of follow-up. 
For patients with more advanced-stage disease and microscopic or gross residual disease, chemotherapy and/or radiation therapy are not indicated. Scant evidence exists that postoperative chemotherapy or radiation therapy alters the course of this disease in any beneficial way.      In a study of 364 patients without residual tumor, adjuvant therapy had no effect on disease-free or corrected survival when stratified for disease stage.  Patients without residual tumor who received no adjuvant treatment had a survival rate equal to or greater than the treated groups. Currently, no controlled studies have compared postoperative treatment with no treatment.
In a review of 150 patients with borderline ovarian tumors, the survival of patients with a residual tumor of less than 2 cm was significantly better than survival for those with a residual tumor from 2 to 5 cm and more than 5 cm.  Whether invasive implants imply a worse prognosis remains an unsettled question. Some investigators have correlated invasive implants with poor prognosis,  while others have not.   Some studies have suggested that it may be possible to use DNA ploidy of the tumors to identify those patients who will develop aggressive disease.   A study could not correlate DNA ploidy of the primary serous tumor with survival but found that aneuploid invasive implants were associated with a poor prognosis.  Currently, no evidence indicates that treatment of patients with aneuploid tumors would have an impact on survival. No significant association was found between p53 and HER-2/neu overexpression and tumor recurrence or survival. 
In the face of clinical progression, further tumor reductive surgery followed by chemotherapy is certainly indicated. If the symptom-free interval is long, using chemotherapy after a secondary cytoreductive procedure is not advisable. If, on the other hand, the disease symptomatically recurs rapidly, chemotherapy may be beneficial. Reports have surgically documented the efficacy of chemotherapy on some patients with microscopic or gross residual disease.   A Gynecologic Oncology Group study used melphalan chemotherapy for patients with progressive disease and used cisplatin for melphalan failures. 
Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with stage III borderline ovarian surface epithelial-stromal tumor and stage IV borderline ovarian surface epithelial-stromal tumor. The list of clinical 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.
The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.
Stage Information for Ovarian Low Malignant Potential Tumors
Updated staging information for 2010 (cited FIGO Committee on Gynecologic Oncology and Edge et al. as references 1 and 2, respectively).
This summary is written and maintained by the PDQ Adult Treatment Editorial Board, which is editorially independent of NCI. The summary reflects an independent review of the literature and does not represent a policy statement of NCI or NIH. More information about summary policies and the role of the PDQ Editorial Boards in maintaining the PDQ summaries can be found on the About This PDQ Summary and PDQ NCI's Comprehensive Cancer Database pages.
This PDQ cancer information summary for health professionals provides comprehensive, peer-reviewed, evidence-based information about the treatment of ovarian low-malignant potential tumors. It is intended as a resource to inform and assist clinicians who care for cancer patients. It does not provide formal guidelines or recommendations for making health care decisions.
This summary is reviewed regularly and updated as necessary by the PDQ Adult Treatment Editorial Board, which is editorially independent of the National Cancer Institute (NCI). The summary reflects an independent review of the literature and does not represent a policy statement of NCI or the National Institutes of Health (NIH).
Board members review recently published articles each month to determine whether an article should:
Changes to the summaries are made through a consensus process in which Board members evaluate the strength of the evidence in the published articles and determine how the article should be included in the summary.
The lead reviewers for Ovarian Low Malignant Potential Tumors Treatment are:
Any comments or questions about the summary content should be submitted to Cancer.gov through the Web site's Contact Form. Do not contact the individual Board Members with questions or comments about the summaries. Board members will not respond to individual inquiries.
Some of the reference citations in this summary are accompanied by a level-of-evidence designation. These designations are intended to help readers assess the strength of the evidence supporting the use of specific interventions or approaches. The PDQ Adult Treatment Editorial Board uses a formal evidence ranking system in developing its level-of-evidence designations.
PDQ is a registered trademark. Although the content of PDQ documents can be used freely as text, it cannot be identified as an NCI PDQ cancer information summary unless it is presented in its entirety and is regularly updated. However, an author would be permitted to write a sentence such as “NCI’s PDQ cancer information summary about breast cancer prevention states the risks succinctly: [include excerpt from the summary].”
The preferred citation for this PDQ summary is:
National Cancer Institute: PDQ® Ovarian Low Malignant Potential Tumors Treatment. Bethesda, MD: National Cancer Institute. Date last modified <MM/DD/YYYY>. Available at: http://cancer.gov/cancertopics/pdq/treatment/ovarian-low-malignant-potential/HealthProfessional. Accessed <MM/DD/YYYY>.
Images in this summary are used with permission of the author(s), artist, and/or publisher for use within the PDQ summaries only. Permission to use images outside the context of PDQ information must be obtained from the owner(s) and cannot be granted by the National Cancer Institute. Information about using the illustrations in this summary, along with many other cancer-related images, is available in Visuals Online, a collection of over 2,000 scientific images.
Based on the strength of the available evidence, treatment options may be described as either “standard” or “under clinical evaluation.” These classifications should not be used as a basis for insurance reimbursement determinations. More information on insurance coverage is available on Cancer.gov on the Coping with Cancer: Financial, Insurance, and Legal Information page.
More information about contacting us or receiving help with the Cancer.gov Web site can be found on our Contact Us for Help page. Questions can also be submitted to Cancer.gov through the Web site’s Contact Form.
For more information, U.S. residents may call the National Cancer Institute's (NCI's) Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237) Monday through Friday from 8:00 a.m. to 8:00 p.m., Eastern Time. A trained Cancer Information Specialist is available to answer your questions.
The NCI's LiveHelp® online chat service provides Internet users with the ability to chat online with an Information Specialist. The service is available from 8:00 a.m. to 11:00 p.m. Eastern time, Monday through Friday. Information Specialists can help Internet users find information on NCI Web sites and answer questions about cancer.
Write to us
For more information from the NCI, please write to this address:
Search the NCI Web site
The NCI Web site provides online access to information on cancer, clinical trials, and other Web sites and organizations that offer support and resources for cancer patients and their families. For a quick search, use the search box in the upper right corner of each Web page. The results for a wide range of search terms will include a list of "Best Bets," editorially chosen Web pages that are most closely related to the search term entered.
There are also many other places to get materials and information about cancer treatment and services. Hospitals in your area may have information about local and regional agencies that have information on finances, getting to and from treatment, receiving care at home, and dealing with problems related to cancer treatment.
The NCI has booklets and other materials for patients, health professionals, and the public. These publications discuss types of cancer, methods of cancer treatment, coping with cancer, and clinical trials. Some publications provide information on tests for cancer, cancer causes and prevention, cancer statistics, and NCI research activities. NCI materials on these and other topics may be ordered online or printed directly from the NCI Publications Locator. These materials can also be ordered by telephone from the Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237).
Date last modified: 2012-07-09
The following organisations have financed parts of our PhD research project on improving the quality of online cancer information.
This site does not accept advertisemets.
|Back to the Cancer.gov
Questions? Mail them to us!