Early related or unrelated haematopoietic cell transplantation results in higher overall survival and leukaemia-free survival compared with conventional chemotherapy in high-risk acute myeloid leukaemia patients in first complete remission

Between 1996 and 2004, a total of 708 patients were enrolled in the acute myeloid leukaemia (AML) '96 and '02 studies of the East German Study Group (OSHO). Of these, 138 patients (19.5%) had unfavourable cytogenetics defined as complex karyotype, del (5q)/-5, del (7q)/-7, abn (3q26) and abn (11q23). In all, 77 (56%) achieved complete remission 1 (CR1) after induction chemotherapy and were eligible for haematopoietic cell transplantation (HCT). HCT was performed after a median of two cycles of consolidation chemotherapy (CT) in the AML '96 and one cycle in the AML '02 study (P = 0.03). After a median follow-up of 19 months, overall survival (OS) at two years was significantly better in the donor group (52 +/- 9%) versus the no-donor group (24 +/- 8%; P = 0.005). Differences in outcomes were mainly because of a lower relapse incidence in patients after HCT (39 +/- 11%) compared with a higher relapse incidence in patients undergoing CT (77 +/- 10%; P = 0.0005). Treatment-related mortality was low and not statistically significantly different between the two treatment groups (15 +/- 7 and 5 +/- 5% for HCT and chemotherapy, respectively; P = 0.49). We conclude that early HCT from related or unrelated donors led to significantly better OS and leukaemia-free survival compared with chemotherapy in patients with unfavourable karyotype.