Impact of conditioning regimen on outcome of 2-year disease-free survivors of autologous stem cell transplantation (ASCT) for Hodgkin lymphoma (HL).

8043 Background: ASCT is the standard of care for patients with relapsed HL. Most relapses occur in the first 2 years (y) after ASCT and the long term outcomes for 2 y post-ASCT survivors have not been well described. No prospective trials have compared the impact of different conditioning regimens on outcomes. METHODS We searched the Nebraska Lymphoma Study Group database to identify patients with HL who received ASCT from 1984 to 2007. Patients were conditioned with CBV (cyclophosphamide 6000 mg/m2, BCNU 300 mg/m2 and etoposide 600-900 mg/m2) or BEAM (BCNU 300 mg/m2, etoposide 800 mg/m2, cytarabine 800 mg/m2 and melphalan 140 mg/m2). Progression, progression-free survival (PFS) and overall survival (OS) were compared between the 2 regimens while adjusting for significant patient, disease and transplant related characteristics. RESULTS The median duration of follow up was 8 (2-26) y. Among the 461 transplanted patients, during the study period, 330 received CBV and 131 received BEAM. At 2 y post-ASCT, 225 (49%) were alive and disease-free. Median age of patients was 33 (8-64) y. The PFS at 5 y was 92% for the BEAM and 73% for the CBV group (p=0.002). The OS at 5 y was 95% for the BEAM and 87% for the CBV group (p=0.07). The PFS at 10 y was 79% for the BEAM and 59% for the CBV group (p=0.01). The OS at 10 y was 84% for the BEAM and 66% for the CBV group (p=0.02). The cumulative incidence of progression at 5 y was 4% vs 24% (for BEAM and CBV respectively, p<0.01) and at 10 y was 9% vs 33% (for BEAM and CBV respectively, p<0.001). Higher relative risk (RR) of progression (4.54, p<0.001), treatment failure (2.92; p=0.002) and mortality (2.74; p=0.03) was observed with use of CBV compared to BEAM. Higher RR of mortality was also observed with age of 40 y or older at transplant (1.69, p=0.04) and with chemoresistant disease (1.99, p=0.02). CONCLUSIONS Patients with HL, who are disease-free and alive 2 y post-ASCT, have favorable long-term outcomes. In the dose and schedule used, we observed a lower risk of progression and longer survival associated with use of BEAM, as a conditioning regimen, compared to CBV. With this study design, we cannot rule out a selection bias favoring patients transplanted in more recent years.