PCOS increases the risk of some types of cancer.
For instance, some research has shown that risk of cancer of the endometrium (pronounced en-doh-MEE-tree-uhm), the inside lining of the uterus, may be higher for women with polycystic ovary syndrome (PCOS) than it is for women without PCOS.1 Irregular periods, or a lack of periods, can cause the endometrium to build up and become thick. This thickening can lead to endometrial cancer.2,3,4
Data on links between breast cancer, ovarian cancer, and PCOS are limited. While some small studies have suggested that a lack of ovulation, as occurs with PCOS, is linked with an increased risk of breast cancer, other studies have not shown an association.1 While some research has shown more than a doubling of the risk of ovarian cancer in women with PCOS,5 scientists have not confirmed these links in large population studies, and further studies hint that women with PCOS may have a lower risk of ovarian cancer.1,2,6 Therefore, any associations between breast or ovarian cancers and PCOS remain inconclusive.
Learn more about these different types of cancers on the National Cancer Institute website: