Association between smoking and leukemia in two American Cancer Society prospective studies.

The association between smoking and leukemia in men and women was analyzed from the data of two prospective studies. Myeloid leukemia was positively associated with smoking in men in both studies (standardized mortality ratios [SMR], 2.44 and 1.32; P less than 0.05), but not with smoking in women. Lymphatic leukemia showed no elevation in risk in men and women in both studies. Animal studies suggest a real biologic difference in leukemogenic effect between the sexes, but further analyses are needed to characterize the smoking effect of leukemia in women.