Researchers led by Dr. Susan M. Pinney from the University of California, San Francisco (UCSF) and the Cancer Prevention Institute of California presented a new study at the AACR Annual Meeting 2024. The study found a significant link between exposure to per- and polyfluoroalkyl substances (PFAS), commonly known as 'forever chemicals,' in drinking water and an increased risk of breast cancer among women in the San Francisco Bay Area.
The research team analyzed residential water samples from 106 women diagnosed with breast cancer and a matched control group of 106 women without a diagnosis, all part of the California Teachers Study cohort between 1995 and 2015. By combining PFAS measurements in water with geographic information systems, they estimated individual cumulative exposure levels. The findings indicated that women with the highest estimated cumulative exposure to perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) experienced a 17% and 19% increased risk of breast cancer, respectively, compared to those with the lowest exposure.
The study also suggested a stronger association for women who had their first menstrual period at an older age or were diagnosed with estrogen receptor-negative (ER-) breast cancer. This research is noted as one of the first to directly link PFAS in drinking water to breast cancer risk. Dr. Pinney highlighted the need for further, larger studies to confirm these findings and investigate how PFAS specifically impact breast tissue, emphasizing the importance of understanding the health implications of widespread PFAS exposure.
