'Relative' chemotherapy sensitivity: the impact of number of salvage regimens prior to autologous stem cell transplant for relapsed and refractory aggressive non-Hodgkin's lymphoma

The purpose of the study was to assess the impact of number of salvage regimens needed to demonstrate chemotherapy sensitivity on relapse rates, survival, and toxicity following high-dose therapy, and autologous bone marrow transplantation (ABMT) in relapsed or refractory non-Hodgkin's lymphoma. We retrospectively reviewed 136 patients with intermediate-grade lymphoma who underwent ABMT. All patients were treated with salvage therapy, to maximum tumor reduction. Three quarters (102/136) of the patients received one salvage regimen, while 31 (23%) patients received two or more regimens. When compared to patients requiring greater than or equal to two regimens, patients requiring only one salvage regimen to demonstrate chemosensitivity were more likely to have a longer previous CR from initial therapy, (CR greater than or equal to12 months in 47% vs 26%; P=0.04) and to have attained CR with salvage (54% vs 16%; P=0.001). Both median relapse-free survival (RFS) and overall survival (OS) have not yet been reached in patients receiving one salvage regimen (median follow-up 50.6 months). This is superior to the median RFS of 9.1 months (P=0.004) and OS of 11.1 months in patients requiring greater than or equal totwo regimens to demonstrate chemosensitivity (P=0.002). Time to engraftment, toxic deaths and incidence of myelodysplasia were similar in the groups. The survival rate observed in patients requiring greater than or equal totwo salvage regimens, although inferior to that of patients receiving a single salvage regimen, are still generally superior to results in the literature for patients treated with chemotherapy, alone without ABMT. We conclude that high-dose therapy with ABMT is appropriate for lymphoma patients even when disease reduction requires repeated numbers of salvage regimens.