An exploratory study on exposure to bisphenol A analogues and breast cancer risk.

Endocrine disrupting compounds (EDCs) such as Bisphenol A (BPA) and its structural analogues are widely used in consumer products and have raised concerns due to their potential to disrupt hormonal balances and promote carcinogenic processes. In this study, total urinary concentrations of BPA and its analogue compounds were quantified in a Canadian breast cancer case-control group of premenopausal women. A robust and validated analytical method involving extraction, clean-up, and LC-MS/MS analysis was developed to accurately measure 15 bisphenols in urine, including BPA, BPS, BPF, and BPE. The detection frequency was high for BPA (99%) and its analogues (BPS, BPF, BPE), with BPA concentrations being the highest overall. Levels of BPA and BPS were higher in breast cancer cases (BPA: 1.75 ug/L; BPS: 0.40 ug/L) relative to healthy controls (BPA: 1.35 ug/L; BPS:0.29 ug/L). When considering the specific gravity (SG) - standardized BPS data a small, but significant difference is observed between breast cancer case and control women, particularly in women from the control group who had lower BPS SG levels [adjusted least squares means = 0.29, (95% CI: 0.21, 0.40)] compared to women diagnosed with breast cancer [adjusted least squares means = 0.48, 95% CI: (0.33, 0.68); p = 0.0462]. The results suggest that chronic exposure to BPA and structurally related compounds is prevalent, and the subtle differences in bisphenol concentration between cases and controls underscore the need for further investigation into the complex associations between bisphenol analogues and breast cancer risks.