Long-term outcome of high-dose cytarabine-based consolidation chemotherapy for older patients with acute myelogenous leukemia.

Despite reports of improved response and leukemia-free survival for adults with acute myelogenous leukemia, advanced age remains a significant adverse prognostic factor for both response to induction therapy and prolonged leukemia-free survival. In addition to a high incidence of treatment-related complications, older patients may have other disease characteristics which predict for brief remission duration despite intensive consolidation chemotherapy. We analyzed the long-term results of high-dose cytarabine-anthracycline consolidation chemotherapy in older patients and examined the effect of major prognostic factors including a history of myelodysplasia, increased age, and cytogenetics. One hundred and ten patients age > or = 60 with newly diagnosed acute myelogenous leukemia were enrolled on three sequential studies conducted from 1982 to 1996. Fifty-six patients (51%) achieved a complete remission and were eligible for high-dose cytarabine-based consolidation chemotherapy administered in two to three courses. After a median follow-up of surviving patients for seventeen months, twelve patients remain alive with eleven in continued remission. Median remission duration for all eligible patients is nine months and the actuarial leukemia-free survival is 14 +/- 10%. Toxicity of consolidation therapy included treatment-related death in six patients and serious neurotoxicity in five. When compared to younger patients, patients over age 60 sustained a much higher risk of relapse despite successfully completing intensive consolidation therapy, regardless of whether other adverse prognostic features were present. Advanced age in acute myelogenous leukemia is associated with a significantly higher risk of relapse unmodified by the presence or absence of other adverse disease characteristics. Although older patients tolerated intensive therapy designed to address the high risk of relapse, there was no apparent benefit of high-dose cytarabine consolidation alone as post-remission treatment for acute myelogenous leukemia in this population.