Neighborhood obesogenic factors and breast cancer risk and mortality in the Southern community cohort study.

Obesity is an established risk factor for many cancers, including breast cancer. However, the complex nature of the underlying mechanisms, coupled with the interaction between individual characteristics and neighborhood obesogenic attributes, contributes to an energy imbalance and a sedentary lifestyle, promoting obesity. This has posed a challenge to our understanding of neighborhood obesogenic attributes associated with this increased risk of breast cancer. We aim to examine how neighborhood attributes affect breast cancer risk and prognosis in the Southern Community Cohort Study (SCCS). We examined a group of more than 41,000 women living in the southeastern United States. Our investigation focused on understanding the association between multiple neighborhood obesogenic indices, including neighborhood socioeconomic status (nSES), restaurant environment index (REI), retail-food environment index (RFEI), park and recreational facilities, and living in a business district. The association between obesogenic indices with breast cancer risk and mortality was analyzed using a multivariable Cox proportional hazards model controlling for individual-level SES and breast cancer risk factors. Additionally, we conducted a stratified analysis of obesogenic indices and breast cancer risk among Black or White participants. Breast cancer was diagnosed in 1,289 participants (3.1%), including 393 White (3.0%) and 896 Black participants (3.2%). Overall, no significant associations were found between neighborhood obesogenic factors and breast cancer risk. However, when analyzed by race and menopausal status, the REI showed an increased risk among White participants (aHR = 1.65, 95% CI 1.06–2.56, p = 0.004, tertile 3 vs. None), particularly postmenopausal women (aHR = 2.39, 95% CI 1.12–5.14, p = 0.024, tertile 3 vs. None). The REI was significantly associated with breast cancer mortality (aHR = 0.38, 95% CI 0.16–0.93, p = 0.035, tertile 1 vs. None). As a conclusion, the REI showed an increased risk among White participants largely attributed to postmenopausal women. The restaurant environment index was associated with reduced breast cancer mortality.