Background: Potential cure of acute myeloid leukemia (AML) is now a widely accepted idea, but it is uncertain whether there is heterogeneity in the failure rate in patients once they have been in complete remission (CR) for various periods of time.
Methods: The long-term outcomes were analyzed in 1069 consecutive AML patients in first CR who were diagnosed and treated at the University of Texas M. D. Anderson Cancer Center between 1991 and 2003. RESULTS.: The failure rates as yearly risk of treatment failure were 69.1 in the first year, 37.7 in the second year, 17.0 in the third year, 7.6 in the fourth year, and 6.6 in the fifth year, suggesting that 3 years from the CR date is a convenient time to consider patients potentially cured. The effect of cytogenetics on relapse-free survival (RFS) remained constant throughout the first 3 years, whereas the effect of age increased with time. The probability of RFS for patients alive without disease recurrence at 3 years was 84.0% at 6 years. When the interaction between age and cytogenetics was examined for these patients, the outcomes of those with favorable cytogenetics were found to be excellent regardless of age. However, in the intermediate cytogenetic group, although patients aged <60 years had excellent outcomes, those aged > or =60 years were found to be at a substantial risk of disease recurrence even after 3 years of CR, with a 6-year RFS rate of 56.5%. There were only 6 patients with adverse cytogenetics in this cohort.
Conclusions: The results of the current study demonstrate that the risk of treatment failure differs over time according to a combination of cytogenetics and age.