Cigarette smoking and the risk of adult leukemia: Results from the Three Mile Island cohort study

Smoking is an unconfirmed risk factor for the development of leukemia. The authors examined the potential link using data from the Three Mile Island cohort for the period 1979-1995. Eligible for analysis were 24,539 individuals aged 14 years or older who were followed up over 16 years from the Three Mile Island cohort. The authors identified all incident leukemia cases through the Pennsylvania Department of Health Cancer Registry. They used the Cox proportional hazards model to evaluate the relationships and observed 42 incident leukemia cases, including 15 acute myeloid leukemia (AML) cases, in the cohort. After controlling for other confounding factors, the authors found current smoking to be associated with an increased risk of adult AML (relative risk = 3.47; 95% confidence interval = 1.002-11.99). The authors also observed a marginally significant linear trend of risk of AML associated with the number of years smoked (p = .06). The results from this study suggested that cigarette smoking was associated with an increased risk of adult AML. Further investigation is required to confirm these findings.