Autologous is superior to allogeneic hematopoietic cell transplantation for acute promyelocytic leukemia in second complete remission

To identify favored choice of transplantation in patients with acute promyelocytic leukemia (APL) in second complete remission, we studied 294 patients with APL in second complete remission (CR2) receiving allogeneic (n = 232) or autologous (n = 62) hematopoietic cell transplantation (HCT) reported to the Center for International Blood and Marrow Transplantation Research (CIBMTR) from 1995 to 2006, including 155 with pre-HCT PML/RAR∝ status (49% of allogeneic and 66% of autologous). Patient characteristics and transplantation characteristics, including treatment-related mortality, overall survival (OS), and disease-free survival, were collected and analyzed for both univariate and multivariate outcomes. With median follow-up of 115 (allogeneic) and 72 months (autologous), 5-year disease-free survival (DFS) favored autologous with 63% (49% to 75%), compared with allogeneic at 50% (44% to 57%) (P = .10). OS was 75% (63% to 85%) versus 54% (48% to 61%) (P = .002), for autologous and allogeneic transplantation, respectively. Multivariate analysis showed significantly worse DFS after allogeneic HCT (hazard ratio [HR], 1.88; 95% confidence interval [CI], 1.16 to 3.06; P = .011) and age > 40 years (HR, 2.30; 95% CI, 1.44 to 3.67; P = .0005). OS was significantly worse after allogeneic HCT (HR, 2.66; 95% CI, 1.52 to 4.65; P= .0006); age > 40 (HR, 3.29; 95% CI, 1.95 to 5.54; P < .001), and first complete remission < 12 months (HR, 1.56; 95% CI, 1.07 to 2.26; P = .021). Positive pre-HCT PML-RAR∝ status in 17 of 114 allogeneic and 6 of 41 receiving autologous transplantation did not influence relapse, treatment failure, or survival in either group. The survival advantage for autografting was attributable to increased treatment-related mortality (TRM) in the allogeneic group of 30% compared to 2% in the autologous group, in addition to the added mortality associated with GVHD. We conclude that autologous HCT yields superior OS for APL in CR2. Long-term DFS in autologous recipients, even with minimal residual disease-positive grafts, remains an important subject for further study.