Cigarette Smoking and Breast Cancer Risk in Hispanic and Non-Hispanic White Women: The Breast Cancer Health Disparities Study

Objective: Few epidemiological studies have included Hispanics with the evaluation of the effects of cigarette smoking and breast cancer. We examined the relationship between cigarette smoking, ethnicity, and breast cancer risk using data from the Breast Cancer Health Disparities Study (BCHDS). Materials and Methods: The BCHDS is a consortium of three population-based case-control studies, including U.S. non-Hispanic whites (NHWs) (1,525 cases; 1,593 controls), U.S. Hispanics/Native Americans (1,265 cases; 1,495 controls), and Mexican women (990 cases; 1,049 controls). Multivariable logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Results: Breast cancer risk was elevated among Mexican former smokers (OR 1.43, 95% CI 1.04-1.96) and among those who smoked >= 31 years (OR 1.95, 95% CI 1.13-3.35), compared to never smokers. In addition, Mexican former smokers with a history of alcohol consumption had increased breast cancer risk (OR 2.30, 95% CI 1.01-5.21). Among NHW premenopausal women, breast cancer risk was increased for smoking >= 20 cigarettes per day (OR 1.61, 95% CI 1.07-2.41). Conclusion: Our findings suggest the possibility of ethnic differences with the associations between cigarette smoking and breast cancer risk.