Occupational exposure to estrogenic chemicals and the occurrence of breast cancer: An exploratory analysis

Overall, 29.5% of cases and 32.5% of controls had probable occupational exposure to one or more xenoestrogens. Probable exposure to nonylphenol (21.5% of cases, 21.4% of controls), butyl benzyl phthalate (10.0% of cases, 13.2% of controls), BHA (7.3% of cases, 9.6% of controls), bisphenol A (9.6% of cases, 11.6% of controls), and 4-tert-butylphenol (2.7% of cases and 5.3% of controls) were relatively commons, while probable exposure to the other xenestrogens was rare. Only PCBs and 4-octylphenol were associated with moderate increase in the odds of breast cancer (PCBs: 5 exposed cases and 6 exposed controls, adjust odds ratio: 3.2, 95% CI = 0.8-12.2, and 4-octylphenol: 6 exposed cases and 5 exposed controls, adjusted odds ratio: 2.9, 95% CI = 10.8).