Allogeneic and autologous stem cell transplantation with busulfan, cyclophosphamide, and etoposide conditioning therapy for relapsed/refractory non-Hodgkin lymphoma

Abstract

The optimal stem cell transplantation (SCT) conditioning therapy for relapsed/refractory non-Hodgkin lymphoma (NHL) is not clearly defined. In a retrospective analysis, we examined 25 patients with "high risk" relapsed/refractory NHL who received busulfan, cyclophosphamide, and etoposide (Bu/Cy/VP16) conditioning with autologous or allogeneic SCT. The majority of patients had aggressive histology and 52% had primary refractory NHL. Furthermore, 48% of patients had chemotherapy-resistant disease at the time of SCT. Fifty-six percent of patients underwent allogeneic SCT, while 44% had autologous SCT. The median engraftment time for neutrophils and platelets was 13.5 and 14 days, respectively. The 100-day treatment-related mortality (TRM) was 16%, while the 2-year non-relapse mortality (NRM) rate was also 16%. At a median follow-up of 15 months, the estimated 2year disease-free survival (DFS) rate was 64% (95% confidence interval (CI): 36%-82%) and the estimated 2-year overall survival (OS) was 69% (95% CI: 40%-86%). Furthermore, the 2-year disease-specific survival (DSS) rate was 73% (95% CI: 40%-90%). Using Cox proportional hazard modeling, the International Prognostic Index at time of relapse predicted DFS and OS. Altogether, Bu/Cy/VP16 was associated with early TRM; however, late toxicities (including NRM) were uncommon resulting in relatively good survival rates in a high-risk relapsed/refractory NHL population.