Cigarette smoking and leukemia.

Cigarette smoking has not been consistently associated with the subsequent development of leukemia. However, many of the earlier epidemiologic studies of leukemia have not considered specific histologic subtypes separately. The association between cigarette smoking and adult acute nonlymphocytic leukemia was examined in a case-control study of 114 patients and 133 controls. Cigarette smoking was associated with a significantly increased risk of acute myelocytic leukemia (relative risk estimate = 1.78, 95% confidence interval = 1.01 to 3.15) along with a significant (P less than 0.001) dose-response based on the total number of years of cigarette smoking. Since this is a preliminary study, more analyses of other epidemiologic studies are needed before it can be concluded that there is a causal association.