Polycystic Ovary Syndrome (PCOS) is a prevalent endocrine condition impacting women of reproductive age. In women with PCOS, several fluid-filled cysts form along the periphery of the ovary and harbor immature follicles that do not consistently release mature eggs from the ovary, as observed in women with regular ovulation (1). Globally, PCOS impacts roughly 8–13% of women (2).
Although PCOS is primarily recognized for inducing irregular menstruation, infertility, and metabolic disorders, there is growing concern regarding its possible association with specific cancer types.
PCOS and Endometrial Cancer: Hormonal imbalance in PCOS women can cause prolonged exposure to estrogen, which stimulates the growth of the endometrial lining of the uterus. When the uterine lining builds up significantly without being shed, it can increase the risk of endometrial hyperplasia, a condition where the endometrial tissue becomes abnormally thick. Over time, this can lead to the development of endometrial cancer (3). Although there is evidence in the literature that polycystic ovarian syndrome (PCOS) and endometrial cancer are connected, it is unclear how strong this link is due to limited data and inconsistency of findings. Furthermore, it is still unclear if confounding variables like age and body mass index (BMI) impact the disease risk level (4).
PCOS and Ovarian Cancer: PCOS may increase the risk of ovarian cancer due to increased androgen exposure, which is a characteristic of PCOS. This elevated androgen exposure significantly raises the risk of ovarian cancer, especially in women who experience prolonged anovulation (5). This can lead to persistent follicular cyst production and hormonal imbalances that stimulate the growth of malignant cells in the ovaries. However, the link between PCOS and ovarian cancer remains contested, with some research finding no apparent association.
PCOS and Breast Cancer: There has always been controversies about the causal relationship between PCOS and breast cancer. A recently published article highlighted the increased risk of breast cancer among women with a history of PCOS, describing that the increased risk was seemingly confined to postmenopausal women (6). The link between PCOS and breast cancer is still not wholly proven; some studies show no association (7), while others suggest that the long-term estrogen exposure and insulin resistance often seen in women with PCOS may modestly raise their risk.
PCOS and other Gastrointestinal Cancers: The correlation between PCOS and other gastrointestinal cancers hasn’t been as widely correlated as observed with gynecological cancers. In a case-control study, PCOS was strongly associated with an increased risk of pancreatic cancer (8). However, this is the second study to establish the correlation, making it difficult to generalize the findings.
Additionally, researchers have hypothesized that there is a slightly increased risk of colorectal cancer in PCOS women due to insulin resistance and obesity, which are common in PCOS. These variables contribute to the development of colorectal tumors by fostering chronic inflammation and cell proliferation (9).
What do these findings mean for Women with PCOS?
The findings on the connection between PCOS and various cancers highlight the importance of proactive health management for women with this condition. Women with PCOS, especially those with prolonged lack of ovulation, are at a heightened risk for endometrial cancer, attributed to prolonged exposure to unrestricted estrogen. While the overall percentage of women with PCOS developing cancer remains small, other factors like obesity, genetics, and age can amplify these risks.
Emerging research also hints at a possible, but less clear, association with ovarian and breast cancers, potentially linked to hormonal and metabolic imbalances. Furthermore, limited studies suggest a connection to gastrointestinal cancers like pancreatic & colorectal cancer, though more robust data is needed to generalize these findings.
Given these risks, regular screenings and proactive management are essential. Routine gynecological exams, pap smears, and imaging tests can facilitate the early detection of abnormalities, improving outcomes. Lifestyle modifications such as maintaining a healthy weight, following an anti-inflammatory diet, and managing insulin resistance through exercise or medication can also significantly reduce cancer risk.
Hormonal therapies like oral contraceptives can also regulate estrogen and progesterone levels, lowering the risk of endometrial hyperplasia and other related cancers.
Tailored communication and individualized care plans are also vital to ensuring that women with PCOS remain informed and take appropriate steps to safeguard their health. While the risks are noteworthy, they can be managed effectively with early interventions and consistent medical follow-ups.
References
1. Mayo Foundation for Medical Education and Research. (2022, September 8). Polycystic ovary syndrome (PCOS). Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/pcos/symptoms-causes/syc-20353439#
2. World Health Organization. (n.d.). Polycystic ovary syndrome. World Health Organization. https://www.who.int/news-room/fact-sheets/detail/polycystic-ovary-syndrome
3. Cheng-Che Shen, Albert C. Yang, Jeng-Hsiu Hung, Li-Yu Hu, Shih-Jen Tsai, A Nationwide Population-Based Retrospective Cohort Study of the Risk of Uterine, Ovarian and Breast Cancer in Women With Polycystic Ovary Syndrome, The Oncologist, Volume 20, Issue 1, January 2015, Pages 45–49, https://doi.org/10.1634/theoncologist.2014-0311
4. Johnson JE, Daley D, Tarta C, Stanciu PI. Risk of endometrial cancer in patients with polycystic ovarian syndrome: A meta‑analysis. Oncol Lett. 2023 Mar 8;25(4):168. doi: 10.3892/ol.2023.13754. PMID: 36960190; PMCID: PMC10028221.
5. Shetty C, Rizvi SMHA, Sharaf J, Williams KD, Tariq M, Acharekar MV, Guerrero Saldivia SE, Unnikrishnan SN, Chavarria YY, Akindele AO, Jalkh APC, Eastmond AK, Hamid P. Risk of Gynecological Cancers in Women With Polycystic Ovary Syndrome and the Pathophysiology of Association. Cureus. 2023 Apr 7;15(4):e37266. doi: 10.7759/cureus.37266. PMID: 37162768; PMCID: PMC10164440.
6. Frandsen, C.L.B., Nøhr, B., Gottschau, M. et al. Polycystic ovary syndrome and risk of breast cancer in premenopausal and postmenopausal women: a nationwide population-based cohort study. Breast Cancer Res Treat 208, 535–542 (2024). https://doi.org/10.1007/s10549-024-07467-8
7. Barry, J. A., Azizia, M. M., & Hardiman, P. J. (2014). Risk of endometrial, ovarian and breast cancer in women with polycystic ovary syndrome: A systematic review and meta-analysis. Human Reproduction Update, 20(5), 748–758. https://doi.org/10.1093/humupd/dmu012
8. Peeri NC, Landicino MV, Saldia CA, Kurtz RC, Rolston VS, Du M. Association Between Polycystic Ovary Syndrome and Risk of Pancreatic Cancer. JAMA Oncol. 2022 Dec 1;8(12):1845-1847. doi: 10.1001/jamaoncol.2022.4540. Erratum in: JAMA Oncol. 2022 Dec 1;8(12):1856. doi: 10.1001/jamaoncol.2022.5738. PMID: 36201203; PMCID: PMC9539727.
9. Newman, M. (2024, October 21). New perspectives on PCOS. Endocrine News. https://endocrinenews.endocrine.org/new-perspectives-on-pcos/
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