Identical outcome after autologous or allogeneic genoidentical hematopoietic stem-cell transplantation in first remission of acute myelocytic leukemia carrying inversion 16 or t(8;21): A retrospective study from the European Cooperative Group for Blood and Marrow Transplantation

Purpose Patients with acute myelocytic leukemia carrying inversion 16 (inv16) or t(8;21) have a better initial response to high-dose cytarabine than patients without these chromosomal abnormalities. They presently do not undergo transplantation in first remission (CR1), but there is concern about late relapses. Patients and Methods From 1990 to 2004, 325 adult patients received transplantations in CR1 (159 patients with inv16 and 166 patients with t(8;21), including 35 and 60 patients, respectively, with additional chromosomal abnormalities). Genoidentical allografts were performed in 64 patients with inv16 and 81 patients with t(8;21), and autografts were performed in 95 patients with inv16 and 85 patients with t(8;21). Results In patients with inv16, after allogeneic and autologous transplantation, the 5-year leukemia-free survival (LFS) rates were 59% and 66% (P = .5), the relapse incidence (RI) rates were 27% and 32% (P = .45), and the transplantation-related mortality (TRM) rates were 14% and 2% (P = .003), respectively. Female patients had a lower RI and a higher LFS. Additional chromosomal abnormalities, compared with no additional abnormalities, were associated with lower RI rate (12% v 34%, respectively;P = .01) and higher 5-year LFS rate (78% v 59%, respectively;P = .04). In patients with t(8;21), after allogeneic and autologous transplantation, the 5-year LFS rates were 60% and 66% (P = .69), the RI rates were 15% and 28% (P = .03), and the TRM rates were 24% and 6% (P = .003), respectively. Younger age and a lower WBC count at diagnosis were associated with a lower TRM and a better LFS. The TRM was lower and the RI was higher in patients with autologous transplantations versus allogeneic transplantations. Conclusion Both autologous and allogeneic transplantation resulted in similar outcomes.