Long-term follow-up of patients with acute myeloid leukemia surviving and free of disease recurrence for at least 2 years after autologous stem cell transplantation: A report from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

BACKGROUND Leukemia recurrence is a major cause of treatment failure after autologous stem cell transplantation for acute myeloid leukemia (AML). It usually occurs within the first 2 years after transplantation. The goal of the current retrospective study was to assess the follow-up of and characterize risk factors for outcome among patients who survived free of disease recurrence after this period. METHODS The analysis included 3567 adults (median age, 45 years) with AML who underwent autografting during the first (86% of patients) or second (14% of patients) complete remission between 1990 and 2008. The stem cell source was the bone marrow in 32% of patients or the peripheral blood in 68% of patients. The median follow-up was 6.9 years. RESULTS At 5 years and 10 years after transplantation, the probability of leukemia-free survival was 86% and 76%, respectively; the recurrence incidence was 11% and 16%, respectively; and the nonrecurrence mortality rate was 3% and 8%, respectively. The observed survival was decreased compared with the expected survival of the general European population. In a multivariate analysis, decreased probability of leukemia-free survival was demonstrated for patients who underwent peripheral blood autologous stem cell transplantation; had French-American-British subtypes M0, M6, or M7; and were of an older age. The same factors were found to be associated with an increased risk of disease recurrence. Nonrecurrence mortality was found to be affected by older age. CONCLUSIONS The results of the current analysis indicate that late recurrences remain a major concern after autologous stem cell transplantation among patients with AML, indicating the need for close monitoring of minimal residual disease and additional leukemic control measures after transplantation.