Abstract A90: Anthropometry, cigarette smoking, alcohol consumption, and the risk of thyroid cancer in the U.S. Radiologic Technologists Study

A90

Several case-control studies suggest that BMI may increase and cigarette smoking may reduce the risk of thyroid cancer, but results from prospective studies are limited. We investigated the associations between anthropometric factors, cigarette smoking, alcohol consumption and thyroid cancer risk by following a cohort of 67,055 female and 20,557 male radiologic technologists in the United States from 1983 through 2006. Hazards ratios (HRs) and 95% confidence intervals (CIs) were calculated using proportional hazards models adjusted for age, sex, smoking status, and benign thyroid conditions, and where appropriate, height or BMI. After a mean follow-up of 15.8 years, 268 (229 female and 39 male) incident thyroid cancer cases were ascertained. Obesity (BMI ≥30.0 kg/m²) was associated with an increased risk of thyroid cancer (HR for women= 1.74, 95% CI 1.22, 2.49; HR for men= 2.27, 95% CI 1.00, 5.13) compared to BMI in the normal range (18.5-24.9 kg/m²). Compared to never smokers, current but not former smokers had a reduced risk of thyroid cancer (HR for women= 0.52, 95% CI 0.34, 0.79; HR for men= 0.28, 95% CI 0.08, 0.94). Alcohol consumption and smoking duration and intensity were not associated with thyroid cancer after adjustment for current smoking. The results were similar after restricting to confirmed (N=223, 83%) or papillary (N=191, 86%) thyroid cancers. We estimate that obesity may account for 9% of thyroid cancers in this cohort and 22% of incident thyroid cancers in the United States currently. In this prospective study, obesity increases and current cigarette smoking decreases the risk of thyroid cancer in both women and men.

Citation Information: Cancer Prev Res 2008;1(7 Suppl):A90.