Improved Relapse Free Survival Is Predicted by a Negative Pre-Transplant FDG-PET Scan Following Salvage Chemotherapy for Relapsed Diffuse Large B Cell Lymphoma (DLBCL) Treated with Autologous Stem Cell Transplantation.

Abstract

Introduction FDG-PET imaging is a powerful predictor of both positive and negative outcome of initial therapy for DLBCL. Existing data on the utility of PET to predict outcome of ASCT have included a range of histological subtypes, limiting its direct applicability to the setting of DLBCL.Methods Data from 41 consecutive patients who had PET scans immediately prior to undergoing ASCT for treatment of first relapse of de novo DLBCL were analysed. We compared the clinical characteristics, event free survival (EFS) and overall survival (OS) of those with residual FDG avid disease (n=21) against those without FDG avid disease (n=20).Results The median age was 53(18–71). Patient characteristics are shown in the table. At 3 years, the OS was 67(±8)%, and the EFS was the 62(±8)%. EFS for PET positive patients was 38(±12)% vs 79(±9%) for PET negative patients (p=0.04). OS was 37(±17%) vs 81(±10%) (p=0.08) respectively.Conclusion Excellent EFS and OS can be anticipated from ASCT when undertaken in those who have achieved a PET negative remission following salvage chemotherapy. Conversely, failure to achieve a PET negative remission after salvage chemotherapy in relapsed DLBCL predicts for a poorer, but not irretrievable outcome after ASCT, suggesting that a proportion of PET positive patients can be successfully salvaged by either ASCT or post-ASCT salvage therapies.Patient CharacteristicsPET Positive (n=21) PET negative (n=20)PET negative (n=20)Female28%40%Median Age (Range)53 (28–65)53(81–71)Salvage RegimenICE ±R 66%ICE ±R 80%Conditioning RegimenBEAM 47%, SBCNU 23% BuMel 14% other 16%BEAM 25%, SBCNU 25% , BuMel 25% other 25%Rituximab with salvage71%95%Rituximab in initial therapy33%25%RT with salvage or ASCT43%25%