Outdoor air pollution and terminal duct lobular involution of the normal breast

Breast Cancer Research

Nicole M. Niehoff¹  Alexandra J. White¹  Alexander P. Keil²  Shaoqi Fan³  Gretchen L. Gierach³  Rena R. Jones⁴ 

[1] Epidemiology Branch, National Institute of Environmental Health Sciences, 111 TW Alexander Drive, 27709, Research Triangle Park, NC, USA;Epidemiology Branch, National Institute of Environmental Health Sciences, 111 TW Alexander Drive, 27709, Research Triangle Park, NC, USA;Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA;Integrative Tumor Biology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA;Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA;

关键词: Air pollution;    Particulate matter;    Terminal duct lobular units;    Breast involution;    Breast cancer;   

DOI  :  10.1186/s13058-020-01339-x

来源: Springer

【 摘 要 】

BackgroundExposure to certain outdoor air pollutants may be associated with a higher risk of breast cancer, though potential underlying mechanisms are poorly understood. We examined whether outdoor air pollution was associated with involution of terminal duct lobular units (TDLUs), the histologic site where most cancers arise and an intermediate marker of breast cancer risk.MethodsPathologist-enumerated TDLUs were assessed in H&E (hematoxylin and eosin)-stained breast tissue sections from 1904 US women ages 18–75 who donated to the Susan G. Komen Tissue Bank (2009–2012). The 2009 annual fine particulate matter < 2.5 μm in diameter (PM2.5) total mass (μg/m3) at each woman’s residential address was estimated from the Environmental Protection Agency’s Downscaler Model combining Community Multiscale Air Quality (CMAQ) System modeling with air quality monitoring data. We secondarily considered CMAQ-modeled components of PM2.5 and gaseous pollutants. We used K-means clustering to identify groups of individuals with similar levels of PM2.5 components, selecting groups via cluster stability analysis. Relative rates (RRs) and 95% confidence intervals (95% CIs) for the association between air pollutants and TDLU counts were estimated from a zero-inflated negative binomial regression model adjusted for potential confounders.ResultsPM2.5 total mass was associated with higher TDLU counts among all women (interquartile range (IQR) increase, RR = 1.06; 95% CI: 1.01–1.11). This association was evident among both premenopausal and postmenopausal women (premenopausal RR = 1.05, 95% CI: 1.00–1.11; postmenopausal RR = 1.11, 95% CI: 1.00–1.23). We identified 3 groups corresponding to clusters that varied geographically and roughly represented high, medium, and low levels of PM2.5 components relative to population mean levels. Compared to the cluster with low levels, the clusters with both high (RR = 1.74; 95% CI: 1.08–2.80) and medium (RR = 1.82; 95% CI: 1.13–2.93) levels were associated with higher TDLU counts; although not significantly different, the magnitude of the associations was stronger among postmenopausal women.ConclusionsHigher PM2.5 levels were associated with reduced TDLU involution as measured by TDLU counts. Air pollution exposure may influence the histologic characteristics of normal tissue which could in turn affect breast cancer risk.

【 授权许可】

CC BY