PERSISTENCE OF CIRCULATING T(14-18)-POSITIVE CELLS IN LONG-TERM REMISSION AFTER RADIATION-THERAPY FOR LOCALIZED-STAGE FOLLICULAR LYMPHOMA

Purpose: To determine the prevalence of circulating t(14;18)-positive cells in patients with long-term remission after radiation therapy for stage I and II follicular lymphoma. Patients and Methods: Peripheral-blood mononuclear cells from 21 patients in continuous remission were examined by a two-step polymerase chain reaction (PCR) assay for the detection of cells carrying a t(14;18) translocation with a breakpoint within the major breakpoint region (MBR) or minor cluster region (mcr). Results: Follow-up duration was between 25 and 160 months, with a median of 6.5 years. Thirteen patients (62%) showed negative results on repetitive testing. Cells that were t(14;18)-positive were found in eight patients (38%), all carrying a breakpoint in the MBR. One patient relapsed in each group. Conclusion: Circulating t(14;18)-positive cells can persist in a high percentage of follicular lymphoma patients in long-term complete remission (CR) after radiation treatment for stage I and II disease. The significance of minimal residual t(14;18)-positive cells with regard to the risk of relapse needs to be investigated in further prospective long-term studies. © 1993 by American So-ciety of Clinical Oncology.