Intensive conventional-dose chemotherapy for stage IV low-grade lymphoma: High remission rates and reversion to negative of peripheral blood bcl-2 rearrangement

Background: Advanced-stage low-grade lymphoma is characterized by initial responsiveness to many conventional therapies but ultimate relapse. Intensive therapy approaches with non-cross-resistant regimens have not been extensively explored. The polymerase chain reaction (PCR) can be used to monitor for the presence of cells with rearrangement of bcl-2, and provides a sensitive and stringent parameter of disease activity and treatment response that may have clinical utility. Patients and methods: From 1988 to 1992, 138 evaluable patients were treated with 3 sequential chemotherapy regimens, as well as with interferon alfa 2b (IFN) in combination with corticosteroids. Nineteen patients had serial PCR monitoring for bcl-2 rearrangement. Results: Among a subset of 58 patients who had an initial phase of IFN plus prednisone, the response rate was 59%, mostly partial remissions (PR). With the chemotherapy program, 65% have achieved complete remission to date, and 30% PR. By PCR analysis, 13 of 19 tested achieved negative status ('molecular remission'), a much higher frequency of molecular remission than has been seen with standard therapies, and these molecular remissions appear to correlate with a lower likelihood of relapse. Conclusions: Intensive conventional-dose chemotherapy can achieve high rates of remission, even when monitored by the stringent PCR technique.