Five year leukaemia-free survival of 72% and 77% for early stage acute and chronic myeloid leukaemia treated by HLA-identical sibling bone marrow transplantation

Background: HLA-identical sibling bone marrow transplantation is an accepted treatment for patients with acute myeloid leukaemia (AML) and chronic myeloid leukaemia (CML). We have recently reported improving results in HLA-identical sibling transplant over the ten year period 1981-1990. In this report we described the outcome in patients transplanted at St Vincent's Hospital, Sydney between 1989 and 1993. Aims: To determine the leukaemia-free survival, transplant-related mortality rate, and relapse rate for patients with AML or CML given HLA-identical sibling marrow transplants between 1989 and 1993. Methods: Sixty-two patients with AML or CML received high dose busulphan/cyclophos-phamide chemotherapy followed by infusion of T replete, HLA-identical sibling bone marrow. Cyclosporin/short methotrexate was utilised as prophylaxis for graft-versus-host disease, ganciclovir as prophylaxis for cytomegalovirus disease and cotrimoxazole as prophylaxis for Pneumocystis carinii pneumonia. Low dose intravenous heparin was used as prophylaxis for hepatic veno-occlusive disease. Results: The five year disease-free survival for patients with AML transplanted in first complete remission was 72% and for those with CML transplanted in first chronic phase was 77%. The relapse rate for AML transplanted in first complete remission was 15% and for CML in first chronic phase 0%. The transplant-related mortality for AML transplanted in first complete remission was 16% and for CML transplanted in first chronic phase 23%. In contrast, the disease-free survival, relapse rate and transplant-related mortality for patients with AML transplanted outside first complete remission and for CML transplanted beyond first chronic phase was 17%, 57% and 57% respectively. Conclusions: The outcome for patients transplanted for early AML or early CML continues to improve and exceeds that obtainable by conventional therapy. The salvage rate is so low for patients transplanted in later stages of AML or CML that all patients less than 55 years of age with these diseases, who have a HLA-identical sibling donor, should be offered bone marrow transplantation early in their disease course.