Duration of second complete remission in patients with acute myeloid leukemia treated with chemotherapy: a retrospective single-center study.

A total of 168 patients with de novo AML were retreated with chemotherapy at relapse following first CR; 66 patients (39%) achieved a second complete remission (CR). The probability of achieving a second CR was highly dependent on the duration of the first remission. Patients who received no or conventional postremission chemotherapy after second CR had a median remission duration of 7.5 months, and the probability of remaining in remission at 3 years was 24%. Patients with a first CR of more than 12 months had a median second remission duration of 18 months. The probability of a second CCR was 35% at 3 years and 24% at 5 years, whereas none of the patients with a first CR of less than 12 months was in remission at 3 years. Only a poor correlation (p = 0.31) was found when the durations of the first and second CR were compared in patients with a second relapse. Patients with long-lasting remissions and long-term survivors after second CR are characterized by a first CR duration of > 12 months and favorable or normal cytogenetics. The type of salvage treatment seems to be less important for achievement of long-term remission, but it is probably important to administer consolidation chemotherapy after second CR. Other so-far ill-defined factors may be responsible for the suppression of the leukemic clone in patients with long-lasting remissions following chemotherapy for relapse after second CR.