February 22, 1993

Cigarette Smoking and Adult LeukemiaA Meta-analysis

Author Affiliations

From the Division of Chronic Disease Prevention and Health Promotion, Missouri Department of Health, Columbia (Dr Brownson); Departments of Medicine (Drs Brownson and Perry) and Family and Community Medicine (Dr Brownson), University of Missouri School of Medicine, Columbia; Office on Smoking and Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, Ga (Dr Novotny). Dr Novotny is now with the School of Public Health, University of California-Berkeley.

Arch Intern Med. 1993;153(4):469-475. doi:10.1001/archinte.1993.00410040037006

Background:  Increasing evidence suggests that certain forms of adult leukemia may be related to cigarette smoking.

Methods:  To evaluate the association between cigarette smoking and adult leukemia, we conducted a metaanalysis of available studies. Data were identified through an English-language MEDLINE search for the period 1970 through 1992 and through our knowledge of ongoing and unpublished studies. Among the studies identified, the meta-analysis included seven prospective studies and eight case-control studies. The US Surgeon General's criteria were used to assess the evidence for causality.

Results:  A positive association between smoking and certain histologic types of leukemia was found in both prospective and case-control studies. The summary smoking-related risk derived from prospective studies (relative risk, 1.3; 95% confidence interval, 1.3 to 1.4) was greater than that based on case-control data (relative risk, 1.1; 95% confidence interval, 1.0 to 1.2). Prospective data suggested an elevated risk of myeloid leukemia associated with cigarette smoking (relative risk, 1.4; 95% confidence interval, 1.2 to 1.6). Pooled case-control data showed increased smoking-associated risk for acute nonlymphocytic leukemia (relative risk, 1.3; 95% confidence interval, 1.1 to 1.5). Risk of leukemia increased according to the number of cigarettes smoked per day. Population-attributable risk calculations suggested that approximately 14% of all US leukemia cases (including 17% of myeloid and 14% of acute nonlymphocytic leukemias) may be due to cigarette smoking.

Conclusions:  The consistency, temporality, and biologic plausibility of this relationship augment our findings, which support a causal relationship between cigarette smoking and certain forms of adult leukemia. Further studies are needed to examine risk among women, dose-response effects, and variation in risk by histologic type.(Arch Intern Med. 1993;153:469-475)