Autologous stem cell transplantation (ASCT) with immunologically purged progenitor cells in patients with advanced stage follicular lymphoma after early partial or complete remission: toxicity, follow-up of minimal residual disease and survival

The role of autologous stem cell transplant (ASCT) in indolent lymphomas is a controversial issue. From 1994 to 1999, we performed ASCT with immunolog ically purged progenitor cells in 15 patients with advanced stage follicula r lymphoma (FL) after early partial or complete remission. Results of the p urging strategy and follow-up of minimal residual disease after transplant were analyzed with PCR amplification of bcl-2/IgH rearrangement for the t(1 4;18) translocation. A comparison of transplanted patients with a group of controls was carried out to evaluate differences in progression-free surviv al and overall survival. Eighty percent of patients received one chemothera py regimen before ASCT acid were in first remission. All the patients recei ved cyclophosphamide plus hyperfractionated total body irradiation as the c onditioning regimen. Nine patients were transplanted with bone marrow (BM) and six with peripheral blood progenitor cells (PBPC), Engraftment was dela yed in one patient transplanted with BM, Two patients died during the trans plant procedure, Ten of 12 evaluable patients were PCR positive in the BM f or bcl-2 rearrangement at diagnosis. Six of them (60%) were still positive after chemotherapy, and one patient was transplanted with a positive hemato poietic product after purging. With a median follow-up of 27 months, six of eight evaluable patients still remain PCR negative in the BM, With a media n follow-up of 4.7 years from diagnosis, progression-free survival was 83% (95% CI: 63-100), The risk of disease progression of non-transplanted patie nts was 19.2 times higher than that of transplanted patients (P = 0.01), bu t no differences were found in overall survival. Regarding patients in firs t remission, the risk of relapse was 12.6 times higher in non-transplanted than in transplanted patients (P = 0.04), This procedure seems to offer a g ood chance to achieve a PCR-negative state and prolonged freedom from recur rence. According to these results, prospective randomized trials are warran ted.