Characterization and prognostic features of secondary acute myeloid leukemia in a population-based setting: a report from the Swedish Acute Leukemia Registry.

Patients with secondary acute myeloid leukemia (AML) often escape inclusion in clinical trials and thus, population-based studies are crucial for its accurate characterization. In this first large population-based study on secondary AML, we studied AML with an antecedent hematological disease (AHD-AML) or therapy-related AML (t-AML) in the population-based Swedish Acute Leukemia Registry. The study included 3,363 adult patients of which 2,474 (73.6%) had de novo AML, 630 (18.7%) AHD-AML, and 259 (7.7%) t-AML. Secondary AML differed significantly compared to de novo AML with respect to age, gender, and cytogenetic risk. Complete remission (CR) rates were significantly lower but early death rates similar in secondary AML. In a multivariable analysis, AHD-AML (HR 1.51; 95% CI 1.26-1.79) and t-AML (1.72; 1.38-2.15) were independent risk factors for poor survival. The negative impact of AHD-AML and t-AML on survival was highly age dependent with a considerable impact in younger patients, but without independent prognostic value in the elderly. Although patients with secondary leukemia did poorly with intensive treatment, early death rates and survival were significantly worse with palliative treatment. We conclude that secondary AML in a population-based setting has a striking impact on survival in younger AML patients, whereas it lacks prognostic value among the elderly patients.