CLINICAL TRIALS AND OBSERVATIONS Acute leukemia incidence and patient survival among children and adults in the

tion classification for hematopoietic and lymphoid neoplasms has provided a framework for defining acute leukemia (AL) subtypes, although few population-based studies have assessed incidence patterns and patient survival accordingly. We assessed AL incidence rates (IRs), IR ratios (IRRs), and relative survival in the United States (2001-2007) in one of the first population-based, comprehensive as-sessments. Most subtypes of acute my-eloid leukemia (AML) and acute lympho-blastic leukemia/lymphoma (ALL/L) predominated among males, from twice higher incidence of T-cell ALL/L among males than among females (IRR 2.20) to nearly equal IRs of acute promyelo-cytic leukemia (APL; IRR 1.08). Com-pared with non-Hispanic whites, Hispan-ics had significantly higher incidence of B-cell ALL/L (IRR 1.64) and APL (IRR 1.28); blacks had lower IRs of nearly all AL subtypes. All ALL/L but only some AML subtypes were associated with a bimodal age pattern. Among AML sub-types, survival was highest for APL and AML with inv(16). B-cell ALL/L had more favorable survival than T-cell ALL/L among the young; the converse occurred at older ages. Limitations of cancer regis-try data must be acknowledged, but the distinct AL incidence and survival pat-terns based on the World Health Organiza-tion classification support biologic diver-sity that should facilitate etiologic discovery, prognostication, and treat-ment advances. (Blood. 2012;119(1):34-43