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) and nitrogen dioxide (NO2). We previously evaluated the role of PM2.5 and other air pollutants in relation to breast cancer risk in the Sister Study (PMID: 315966020). To improve our ability to evaluate associations with different breast cancer subtypes, we conducted a parallel analysis of 5 large US cohorts and meta-analyzed results; we observed that NO2 was associated with overall breast cancer whereas PM2.5 was significant associated with hormone receptor-negative tumors (in press). The growing evidence of a role for PM2.5 in breast cancer etiology and key next steps was described in a recent invited commentary (PMID: 39467215). Within Sister Study, we have expanded this work to consider the relationship with gynecologic cancers, and have observed that nitrogen dioxide exposure is related to both the incidence of uterine (PMID: 38346713) and ovarian cancer (PMID:39352804) within Sister Study. Beyond criteria pollutants, we have also explored the role of industrial emissions in breast cancer development; higher residential exposure to certain industrial carcinogens, including nickel and trichloroethylene, was associated with breast cancer incidence (PMID:39855262). We have also explored how residential exposure to another potentially important point source, EPA-designated Superfund Sites, may contribute to breast cancer risk. First, using census data we explored demographics of those who lived nearest to Superfund sites. While initial analyses demonstrated minimal demographic differences for living within 3 miles of a site, stratified results revealed that high-hazard, chemically-diverse sites were disproportionately located in areas with higher proportions of racial minorities, greater social vulnerability and lower socioeconomic status (PMID: 39906125). In the Sister Study, we observed that living in proximity to 2 or more sites was associated with an elevated hazard of breast cancer (under review) We have previously observed that use of hair relaxers is related to a higher risk of breast (PMID:31797377), ovarian (PMID:34173819) and uterine (PMID:36245087); yet little is understood about non-reproductive cancers. In new research exploring a range of cancer types, we found that ever use of hair straighteners/relaxers in the year before enrollment was associated with a higher incidence of pancreatic cancer, thyroid cancer and non-Hodgkin's lymphoma (under review). Using paired blood samples from Sister Study taken six years apart, we’ve identified 24 legacy PFAS and 1,802 features annotated as potential PFAS. Targeted PFAS concentrations in Sister Study participants were similar if not slightly higher than samples from women matched by age and calendar year in NHANES and exhibited relatively low temporal variability over a six-year period (PMID:40516284). In contrast, for many novel and emerging PFAS which have been introduced as replacement for the legacy PFAS, we observed increasing abundance over time and greater temporal variability.