Air Pollution and Breast Cancer: An Examination of Modification By Underlying Familial Breast Cancer Risk

Abstract

Background: An increased familial risk of breast cancer may be due to both shared genetics and environment. Women with a breast cancer family history may have a higher prevalence of breast cancer-related gene variants and thus increased susceptibility to environmental exposures. We evaluated whether air pollutant and breast cancer associations varied by familial risk. Methods:Sister Study participants living in the contiguous U.S. at enrollment (2003)(2004)(2005)(2006)(2007)(2008)(2009) (N=48,453), all of whom had at least one first-degree relative with breast cancer, were followed for breast cancer. Annual NO 2 and PM 2.5 concentrations were estimated at the enrollment addresses. We predicted 1-year familial breast cancer risk using the Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm (BOADICEA). Using Cox regression, we estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between each pollutant dichotomized at the median and breast cancer with interaction terms to examine modification by BOADICEA score.Results: NO 2 was associated with a higher breast cancer risk among those with BOADICEA score >90 th percentile (HR=1.28; 95% CI: 1.05-1.56) but not among those with BOADICEA score ≤90 th percentile (HR=0.98; 95% CI: 0.90-1.06) (p-interaction=0.01). In contrast to NO 2 , associations between PM 2.5 and breast cancer did not vary between individuals with BOADICEA score >90 th percentile and ≤90 th percentile (p-interaction=0.26). Conclusions:Our results provide additional evidence that air pollution may be implicated in breast cancer, particularly among women with a higher familial risk.

Exploring the geospatial epidemiology of breast cancer in Iran: identifying significant risk factors and spatial patterns for evidence-based prevention strategies

“…Prior epidemiological studies have established associations between air pollution exposure and increased BC risk, with this relationship modulated by factors such as genetics, ethnicity, diet, and cultural context. Particulate matter components PM10 and PM2.5, in addition to gaseous pollutants like NO2 and SO2, have been linked to heightened BC incidence and mortality, particularly in highly polluted Chinese cities [ 80 , 81 ]. PM2.5, NO2, and traffic-related emissions may act as mammary carcinogens [ 15 , 82 ].…”

A comprehensive review on endocrine toxicity of gaseous components and particulate matter in smog

“…Outdoor exposure to NO 2 is closely associated with lung cancer in females through increased activation of estrogen receptors. A few studies have demonstrated that estrogen receptor activation promoted tumor formation by several genomic and non-genomic pathways ( 52 ). Female lung cancer is closely associated with the activation of estrogen receptor pathway and NO 2 is implicated to activate this pathway ( 53 ).…”

Exposición a material particulado y su relación con el cáncer de mama. Mecanismos fisiopatológicos

“…Es importante tener en cuenta que personas con mayor grado de antecedentes familiares de cáncer de mama, tienen más probabilidades de tener una expresión reducida de los genes de reparación del ADN, y por tanto, es probable que en estas personas sea más fuerte la asociación entre exposición a sustancias como los HAP y el cáncer de mama [34].…”