Are women with PCOS at greater risk of cancer?

According to a new study in Gynecologic Oncology, women who have polycystic ovary syndrome (PCOS) may be at greater risk of developing some types of cancer.

Researchers at the Danish Cancer Society Research Center used the Danish National Patient Register to identify 12,070 women who were diagnosed with PCOS from 1977 to 2012 when they were aged 9 to 49 years. The Danish Cancer Registry was used to follow the cohort through 2012 and compare the incidence of cancer in the cohort against the general Danish female population using standardized incidence rations (SIRs).

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During the course of study, cancer was diagnosed in 279 women with PCOS (SIR = 1.19; 95% confidence interval [CI] = 1.06–1.34). A nearly fourfold increased risk of endometrial cancer was found (numbers observed [N] = 16, SIR = 3.9; 95% CI = 2.2–6.3), which confirms prior findings. Most of the endometrial cancer cases were type 1 (N =  14, SIR = 4.7; 95% CI = 2.6–7.9). The researchers did note however that the excess absolute risk of 13.1 per 100,000 person-years would represent just a few extra cases of endometrial cancer in PCOS patients than in those who don’t have the syndrome. No apparent association was seen between PCOS and breast (N = 59, SIR = 1.1; 95% CI = 0.8–1.4) or ovarian cancer (N = 10, SIR = 1.8; 95% CI = 0.8–3.2). Increased numbers of women with brain (8.2 cases expected vs 18 observed), kidney (1.6 cases expected vs 6 observed), and colon cancer (5.2 cases expected vs 11 observed) were also noted.

The investigators concluded that their results add further support that women with PCOS are at increased risk of endometrial cancer. They also urge further study on the increased risk of brain, colon, and kidney cancer in women with PCOS.

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