Long-Term Follow-Up of Treatment for Acute Myeloid Leukemia with Allogeneic Hematopoetic Cell Transplantation Using BuCy2 as Preparation.

In 1991, we reported the results of 127 patients with Acute Myeloid Leukemia (AML) who underwent conditioning for allogeneic transplant with busulfan, 4 mg/kg on each of 4 days and cyclophosphamide 60 mg/kg on each of 2 days. In the current abstract, we report data on 295 patients, including the initial cohort, who underwent allogenic transplantation for AML from 1984 to 1995 at 7 participating institutions. Median age of patients is 33. One hundred forty nine men and 126 women underwent transplant. All patients received marrow from related HLA-identical donors. One hundred seven patients (36%) remain alive. One hundred forty one patients were transplanted in first remission (group I), 43 in second remission (group II) and 111 patients were in > 2^nd remission or had refractory disease (group III). The median follow-up of patients in the initial study was 3 years and is 12 years in the current study. Seventy-five percent of patients surviving 3 years after transplantation are estimated survivors 12 years after transplant. Relapse (20), chronic GVHD (5) and infection (3) were the major causes of death in patients who died more than 3 years after transplantation. The estimated relapse rate for group I at 3 and 12 years is 18%(95% CI: 2–32%) and 29% (95% CI 11–47%) for group II is 40% (95% CI: 8–72%) and 52% (95% CI: 16–84%), and group III is 59% (95% CI: 37–81%) and 69% (95% CI: 45–93%) respectively. The estimated leukemia-free survival (LFS) for group I at 3 and 12 years is 60% (95% CI: 44–76%) and 47% (95% CI: 29–65%), for group II is 47% (95% CI: 17–77%) and 34% (95% CI: 4– 64%)and group III is 22% (95% CI: 6–38%) and 15% (95% CI: 1–29%) respectively. Remission stage was predictive of long-term LFS (P<0.001), with patients transplanted in first remission doing better than the rest. Older age was a risk factor for late failure (death or relapse beyond 3 years, P=0.05). Remission stage at transplant (p=0.44), chronic GVHD (P=0.08) and acute GVHD (P=0.12) were not significantly predictive of late failure. In conclusion a vast majority of patients alive and well at 3 years post transplant seem destined to be cured. A proportion of patients do fail beyond 3 years, but the remission stage of disease at transplant is not predictive of late failure.