An apparent increase in the incidence of acute nonlymphocytic leukemia in black children.

A community-wide study was conducted to examine time trends in incidence rates of leukemia in children. Cases of acute leukemia, both lymphocytic (ALL) and nonlymphocytic (ANLL), newly diagnosed in children ages 0-19 years in the Baltimore area from 1960 to 1974 were ascertained. Over the 15 years, 286 children with acute leukemia were identified, of whom 77% had ALL. Incidence rates of ALL were two to three times as high in whites as in blacks, and remained virtually unchanged over time. However, the picture was quite different for ANLL. Initially, incidence rates were higher in whites than in blacks, but during the final five years the incidence increased dramatically in blacks so that it actually exceeded the rate among whites. The increase of ANLL in black children occurred primarily in blacks of high socioeconomic status. This suggests that the increase may have resulted from environmental influences associated with upward socioeconomic mobility in the black population in recent years.