Environment and Cancer Epidemiology

National Institute Of Environmental Health Sciences

Investigators

Linked publications, trials & patents

Abstract

To investigate the effects of environmental factors on breast cancer risk we have conducted a number of high-quality population-based studies. We have been working in the Sister Study cohort, a large prospective study of women who have a sister with breast cancer. The Sister Study is a study of over 50,000 women across the United States which has information on exposure to residential criteria air pollutants, including fine particulate matter (PM2.5). PM2.5 is a heterogeneous mixture of pollutants that varies geographically. We evaluated the role of PM2.5 and other air pollutants in relation to breast cancer risk in the Sister Study and demonstrated substantial geographic heterogeneity in associations (PMID: 315966020). For example, for women who lived in similar PM2.5 component profiles and were based in the Western US, PM2.5 was associated with a higher risk of breast cancer whereas PM2.5 was not related to breast cancer risk in other regions. In the Black Womens Health Study, a large prospective US-wide cohort of Black women, we also observed that associations between PM2.5 and breast cancer risk significantly varied by geographic regions (PMID: 33387538). Further, in the Komen Tissue Bank, a population of women without breast cancer who donate normal tissue samples, living in areas of higher exposure to PM2.5 in the Midwest also appears to be related to breast tissue characteristics that are predictive of future breast cancer risk (PMID: 32972455). We recently evaluated the role of toenail metal concentration mixtures in relation to breast cancer risk; we found little to increase in risk for toenail metal concentrations in relation to breast cancer incidence when using quantile g-computation to evaluate the joint effect of multiple metals (PMID: 34268559). We have also explored how toenail metal concentrations may be related to other womens health outcomes, including age at menopause (PMID: 32832842). Another aspect of our work has been considering how use of various hair products is related to womens cancer risk. Following up on our manuscript that observed a higher risk of breast cancer for adult use of permanent hair dye and chemical straighteners (PMID: 31797377), we further explored how adolescent use of these products may be related to breast cancer risk. We found that use of both perms and straighteners between the ages of 10-13 years was associated with a 2-fold higher risk of premenopausal breast cancer (PMID: 33252833). Recently, we have extended this work to be the first investigation of multiple hair products in relation to ovarian cancer risk; frequent straightener use was also associated with an elevated risk of ovarian cancer (PMID: 34173819).