Long-term survival after chemotherapy for acute myeloid leukemia

BACKGROUND Reports on outcomes of chemotherapy trials in acute myeloid leukemia (AML) have rarely included results of long-term follow-up beyond 10 years. The authors therefore chose to review long-term follow-up data from 3 studies conducted by the Southwest Oncology Group (SWOG) between 1978 and 1990. METHODS The analysis included data on 2083 patients enrolled in SWOG studies S7823, S8124, and S8600. The results were based on data available as of November 15, 1996. RESULTS The probability of survival 8 years after entry was 9% in Study S7823, 14% in S8124, and 15% in S8600. For patients age < 50 years, the probabilities were 14%, 24%, and 20%, respectively. For patients ages 50-64 years, the probabilities were 7%, 8%, and 8%, respectively. For those age < 50 years who achieved complete remission, the 8-year probability of disease free survival was 17% in Study S7823, 28% in S8124, 17% with standard dose cytarabine in S8600, and 26% with high dose cytarabine in S8600. Relapse was the major reason for failure after complete remission in all three studies. When the results of the 3 studies were combined, most of the 743 relapses had occurred by Year 3 and nearly all the rest by Year 5. Among the prognostic factors universally available for study, three were highly associated with survival in all three studies: age, French-American-British disease classification, and white blood cell count at diagnosis. CONCLUSIONS In view of the fact that most deaths occurred during the first 3 years, it is appropriate to report the results of clinical trials after patients have been followed for 4 years. Despite modest gains, the results of chemotherapy for AML remain disappointing, especially in the treatment of older patients. Cancer 1997; 80:2199-204. © 1997 American Cancer Society.