Association of breast adipose tissue levels of polychlorinated biphenyls and breast cancer development in women from Chaoshan, China

Polychlorinated biphenyls (PCBs) are implied to be potential risk factors for breast cancer in wildlife and in in vivo and in vitro studies. Epidemiological studies revealed some individual or groups of PCB congeners associated with breast cancer risk, but consistent conclusions are scarce. This study aimed to explore the association between PCB exposure and breast cancer development. Breast adipose tissues were collected, and seven PCB congeners were analyzed by gas chromatography- mass spectrometry (GC-MS). Demographic characteristics, basic clinical data, and pathological diagnosis information were obtained from medical records. The differences in PCB exposure levels among different groups and indices were compared, and the correlation among PCB congeners was evaluated. The order of congener profile by molar concentration was PCB-153 > PCB-138 > PCB-180 > PCB118 > PCB-101 > PCB-52 > PCB-28. Sigma PCB level differed by occupation and residence and was significantly higher at 5559-year-old group than at the other age groups. SPCB level was higher in postmenopausal than in premenopausal women. Decreasing SPCB levels were related with increasing parity among women with progesterone receptor (PR)-positive breast tumors. With increased clinical stage, the SPCB level increased significantly. SPCB level did not differ by tumornode- metastasis classification and PR or human epidermal growth factor receptor 2 (HER2) expression but did differ by estrogen receptor (ER) expression (P = 0.04) without a regularly increasing trend in breast adipose tissue. These results suggest a potential association between PCB exposure and breast cancer development. Further in vitro and in vivo studies are needed to confirm these findings and explain the underlying mechanisms.