Sun Exposure Is Associated with Reduced Breast Cancer Risk among Women Living in the Caribbean: The Atabey Study in Puerto Rico

Abstract

Background: Though inconsistent, there is evidence that sun ascertained with interviewer-administered questionnaires. OR exposure is associated with reduced breast cancer risk. Previous and 95% confidence intervals (CI) were estimated with unconstudies have been conducted in geographical regions with seasonal ditional logistic regression. variation in UV radiation, including periods of low to no exposure, Results: Adjusted breast cancer odds were lower for the highest and among participants mostly of European descent. Puerto Rico tertile of the SEI (ORadj ¼ 0.47; 95% CI, 0.29–0.74). Results were has no significant seasonal fluctuation, with continuous exposure to similar within strata of estrogen receptor status. In analyses stratvery high UV radiation. ified by constitutive skin pigmentation, among participants with Methods: We conducted a population-based case–control darker skin color, breast cancer risk was lower with more sun study of breast cancer among women in metropolitan San Juan, exposure (ORadj ¼ 0.33; 95% CI, 0.16–0.70). Puerto Rico, examining a cumulative sun exposure index (SEI) Conclusions: We found lower risk of breast cancer associated based on a comparison of reflectance of sun-exposed and non-with greater sun exposure in a population living with high, con-exposed skin. A chromameter was used to measure skin tinuous sun exposure. This beneficial finding should be placed in the reflectance and estimate the difference between constitutive context of other effects of sun exposure. (unexposed) and facultative (exposed) skin pigmentation in Impact: Sun exposure is a modifiable factor that may contribute, 307 cases and 328 controls. Breast cancer risk factors were directly or indirectly, to lower breast cancer risk.