Relapse of leukemia after bone marrow transplantation: effect of second myeloablative therapy

Twenty-three patients with recurrent leukemia after bone marrow transplantation (BMT) underwent a second myeloablative therapy followed by second transplant between June 1977 and April 1991. Patients had either acute lymphocytic leukemia (n = 4), acute myelogenous leukemia (n = 7) or chronic myelogenous leukemia (n = 12). The median age was 29 years and the median interval between first and second BMT was 22.6 months. The second preparative therapy consisted of cyclophosphamide (200 mg/kg) and total body irradiation (1200 cGy) in nine patients and busulfan (16 mg/kg) and cyclophosphamide (120-200 mg/kg) with or without etoposide (30-60 mg/kg) in 14 patients. The same sibling donor (three syngeneic, 20 allogeneic) was used for both transplants. All patients demonstrated prompt neutrophil recovery (median 21 days) with donor-derived hematopoiesis documented in 16 of 16 evaluable patients. With a median follow-up of 24 months after second BMT, the survival, event-free survival and probability of remaining in remission at 26 months are 47%, 38% and 76% respectively. Outcome was best in patients with chronic myelogenous leukemia (7/12 survivors) and worst in patients with acute leukemia (2/11 survivors). Thus, the data would suggest that (1) selected patients with recurrent leukemia after BMT can still be cured with myeloablative therapy and second BMT, and (2) further improvements in outcome will be dependent upon the reduction of regimen-related toxicity.