Journal of Clinical Oncology 11(2): 202-208, 1993. is available online.
Journal of Clinical Oncology 11(2): 202-208, 1993. may be available online for subscribers.
Follicular lymphoma originates in follicular-center B cells, usually in the lymph nodes, almost always is composed of two morphologic cell types, and mostly has a chromosomal translocation, t(14;18)(q32;q21), that juxtaposes bcl-2 from chromosome 18 into the immunoglobulin heavy-chain locus on chromosome 14. The cells tend to grow in balls or nodules, so the term follicular does not describe the growth pattern. The lymphomas are classified into small cleaved-cell, mixed-cell, and large-cell lymphomas, based on the frequency of large cells; the growth pattern is more aggressive with a greater proportion of large cells. Small cleaved-cell lymphomas are most responsive to treatment, and even Vitamin D has produced complete responses. Cure rates for Stages I/II and for Stage III disease with radiotherapy may reach 88% and 40%, respectively. For more advanced disease treated with doxorubicin-containing combination chemotherapy with or without radiation, despite frequent and prolonged disease-free survival (up to 75%, with median duration over 8 years), it is not clear that overall survival is increased. For mixed-cell type, high long-term disease-free survival (75-79% at 7 or more years) has been achieved with chemotherapy with C-MOPP or Pro-MACE/MOPP. For large-cell disease, 5-year survivals after Pro-MACE-based chemotherapy is around 29%, but salvage with radiation and chemotherapy has raised this to 61%. The report by the Nebraska group (Anderson et al J Clin Oncol; 11:218, 1993) that occasioned this editorial is reviewed. Stage I/II patients, treated with combination therapy and involved field radiotherapy, had an 88% complete response rate and 76% 3-year survival. For Stage III/IV patients treated with chemotherapy (CAP/BOP) the complete response rate was 49%, but overall survival was 61% at 3 years. Poorer results in advanced-stage follicular large-cell lymphoma could reflect some feature associated with trisomy 7 in at least 25% of patients. Twelve of 17 patients with chromosome 1 abnormalities or trisomy 7 also had abnormalities in chromosome 14q32. The best outcome for early-stage patients was achieved with doxorubicin-containing chemotherapy plus involved-field radiotherapy. The editorial continues with discussion of the concept of at least two stem-cell populations with the one for small cells more genetically stable, generally not in cycle but renewable, and sensitive to radiation but not chemotherapy, in contrast to the genetically unstable, cycling, non-renewable, more chemotherapy sensitive population that gives rise to large cells. The bcl-2 gene may not be a good target for postulated therapy. (32 Refs.)
Rheinische Friedrich- Wilhelms- Universität Bonn