based on an analysis of nearly 3.5 million women in a large Swedish database.
Women with PCOS had a sixfold increased risk of endometrial cancer, a tripling of endocrine gland cancers, and more than a doubling in the risk of ovarian and pancreatic cancers. Once women reached menopausal status, however, their cancer risk was comparable to that of women without a history of PCOS.
“Several carcinogenic processes are associated with PCOS, including dyslipidemia, hyperinsulinemia, and chronic inflammation,” wrote Weimin Ye, MD, PhD, of the Karolinska Institutet, Stockholm, and his colleagues. “Our study indicates that cancer may need to be added to the spectrum of long-term health consequences of PCOS and warrants increased surveillance among those patients.”
The research letter was published online in JAMA Oncology.
The team examined the relationship between PCOS and primary cancers in about 3.5 million women over a span of up to 24 years (1985-2009), although the mean follow-up time was not mentioned. To examine the potential impact of menopause, they conducted separate multivariate logistic regression analyses for those younger than 51 years, and those aged 51 years or older. The analyses controlled for use of some medications (metformin, oral contraceptives, and hormone therapy); as well as educational level (a proxy for socioeconomic status); smoking; parity (a proxy for fertility); parental cancers; and diabetes.
Overall, 14,764 women had been diagnosed with PCOS; they were a mean of 28 years at baseline and 182 developed a primary cancer 1 year or more after PCOS diagnosis.
These women had a 15% overall increased risk of cancer, compared with women without PCOS.
The risks for specific cancers also were increased, compared with women without PCOS, including endometrial (hazard ratio, 2.62), ovarian (HR, 2.16), endocrine (HR, 1.92), pancreatic (HR, 3.4), kidney (HR, 3.0), and skeletal and hematopoietic (HR, 1.69) cancers.
The risks were associated with younger age, however. In the group under age 51 years, the overall risk was 22% higher. The increased risk of specific cancers were endometrial (HR, 6.45), ovarian (HR, 2.55), pancreatic (HR, 6.68), kidney (HR, 4.57), and endocrine (not thyroid) gland (HR, 2.9) cancers.
The authors had no relevant financial disclosures.
SOURCE: Yin W et al. JAMA Oncol. 2018 Nov 29. doi:10.1001/jamaoncol.2018.5188.