11.Higher incidence of relapse with peripheral blood rather than marrow as a source of stem cells in adults with acute myelocytic leukemia autografted during the first remission

PURPOSE: The cell source for autologous stem cell transplantation has shifted from bone marrow (BM) to peripheral blood (PB). In acute myelocytic leukemia (AML), for patients who receive transplants during first complete remission (CR1), no prospective randomized study has compared relapse incidence (RI) to cell source. PATIENTS AND METHODS: We analyzed 2,165 patients who received autografts (1,607 PB and 558 BM) from 1994 to 2006 and were reported to the European Cooperative Group for Blood and Marrow Transplantation with complete research data. Relative to the time of CR1, PB transplants were performed earlier than BM transplants. Because a poorer outcome was associated with a shorter interval from CR1 to transplantation, patients were divided into three groups: BM, early PB (< or = 80 days after CR1), and late PB (> 80 days after CR1) transplantation. RESULTS: In a multivariate analysis adjusted for differences between groups and center, RI was higher with both early PB (56% +/- 3%; hazard ratio [HR], 1.45; 95% CI, 1.11 to 1.9; P = .006) and late PB transplantation (46% +/- 2%; HR, 1.3; 95% CI, 1.06 to 1.59; P = .01) as compared with BM transplantation (39% +/- 2%). This translated into a significantly worse leukemia-free survival (LFS) for early PB transplantation (36% +/- 3%; HR, 0.75; 95% CI, 0.58 to 0.96; P = .02) and a trend for a poorer LFS for late PB (46% +/- 2%; HR, 0.84; 95% CI, 0.7 to 1.01; P = .06) as compared with BM (52% +/- 2%). CONCLUSION: For patients with AML in CR1, risk of relapse is greater with PB transplantation rather than BM, independent of the interval from CR1 to transplantation.