Relapse after allogeneic bone marrow transplantation for acute leukaemia: a survey by the E.B.M.T. of 117 cases.

A multi-centre retrospective analysis on 117 patients relapsing after bone marrow transplantation (BMT) for acute leukaemia was carried out by the Leukaemia Working Party of the European Group for Bone Marrow Transplantation (E.B.M.T.). Forty-one patients had acute myeloid leukaemia (AML) and 76 had acute lymphoblastic leukaemia (ALL). Relapse occurred between 3 and 30 months after BMT and where investigated the leukaemia was found to have relapsed in recipient cells. In 10 cases the relapse was associated with new cytogenetic abnormalities. 74 patients received further treatment for leukaemia. Of these 21 out of 50 with ALL and 11 out of 24 with AML achieved a complete remission and had a median survival of 12 months compared with a median survival of 4 months for untreated patients or patients not achieving complete remission (P less than 0.001). Factors predictive for successful remission induction were a long interval between bone marrow transplant and relapse in ALL patients; and isolated extramedullary relapse. Presenting blast count, karyotype and remission status and number at the time of BMT were not predictive. Donor bone marrow was shown to be responsible for haemopoietic recovery occurring in the 21 out of 31 patients tested who achieved remission using donor karyotype or red blood cell antigens as markers. Nine patients received a second bone marrow transplant but only one became a long-term survivor. The results show that chemotherapy can usually prolong survival in selected patients with acute leukaemia relapsing after BMT but further BMT has a poor outlook.