Time from diagnosis to treatment initiation predicts survival in younger, but not older, acute myeloid leukemia patients.

Acute myeloid leukemia (AML) is considered an oncologic emergency. Delaying induction chemotherapy until molecular testing results return, may benefit some patients but harm others. We examined the effect of time from AML diagnosis to treatment (TDT) on complete remission (CR) and overall survival (OS), using patient characteristics available at diagnosis. Regression models were applied to older (> or = 60 years) and younger (< 60 years) adults, controlling for age, baseline white blood cell count, secondary AML (sAML), and performance status. Median patient age was 60 years (range, 17-87 years), TDT 4 days (range, 1-78 days), and 45% had sAML. Cytogenetic risk distribution was: favorable, 8%; intermediate, 66%; unfavorable, 26%. CR rate was 67% and median OS was 68 weeks in patients younger than 60 years; 55% and 33 weeks in older patients, respectively. In univariate and multivariate analyses, longer TDT was associated with worse CR and OS in younger (univariate: P < .001 in both; multivariate: P < .001 and P = .001, respectively), but not older patients (univariate: P = .45, P = .19; multivariate: P = .63, P = .30, respectively). Results did not change with inclusion of cytogenetic data or in risk group subsets. AML therapy should be initiated immediately in younger patients. Delaying treatment does not seem harmful in older patients, allowing individualized approaches.