#50-S residential proximity at birth to industrial sites and subsequent risk of breast cancer

PURPOSE: To investigate the relationship between residential proximity at birth to industrial sites contracted by the Atomic Energy Commission (AEC) to process radioactive material and the subsequent development of breast cancer (BC) in pre and post menopausal women. METHODS: We conducted a case-control study (n = 3,335) and restricted subjects to residents born in Western New York (n = 1,181). Subjects were further restricted to those born in 1940 or later because the first industrial sites began operating under the AEC contract in 1940. A total of 266 incident, primary, histologically confirmed breast cancer cases and 411 controls frequency matched by age were included in this analysis. Exposure was assessed as distance (in miles) of residence at birth to 13 industrial sites. The closest site was then selected for each subject as a surrogate for environmental exposure. The distance to the closest site was categorized into quartiles based on the distribution in the controls. Odds ratios (OR) and 95% confidence intervals (95% CI) were used to estimate the association between residential proximity and subsequent BC. The ORs were adjusted for age, education, age at menarche, parity, and age at first birth. RESULTS: We observed an adjusted OR of 3.8 (95% CI 1.9–7.7) for premenopausal women residing less than 2.45 miles from the closest site when compared to women residing greater than 8 miles from the closest industrial site. No such association was observed in post-menopausal women. CONCLUSION: These preliminary findings suggest that relatively close residential proximity at birth to industrial sites involved in uranium processing may increase the risk of premen-opausal BC. However, it is unclear whether this association can be attributed to environmental contamination with radioactive material, or some other environmental contaminate also produced at these industrial sites.