Virus, Lifestyle and Genes, Danish Cancer Institute, Strandboulevarden 49, 2100, Copenhagen, Denmark.
Department of Obstetrics and Gynecology, University Hospital of Herlev and Gentofte, Copenhagen, Denmark.
Breast Cancer Res Treat. 2024 Dec;208(3):535-542. doi: 10.1007/s10549-024-07467-8. Epub 2024 Aug 21.
Although some reproductive and metabolic characteristics of polycystic ovary syndrome (PCOS) are known risk factors for breast cancer, the evidence regarding a potential association between PCOS and breast cancer is scarce. In this population-based cohort study including all 1,719,452 women born in Denmark between 1940 and 1993, we investigated the association between PCOS and breast cancer.
PCOS diagnoses, cancer diagnoses, covariates, migrations, and vital status were all obtained from national population and health registers. Hazard ratios (HR) and 95% confidence intervals (CI) for breast cancer overall and for histological subtypes separately were calculated based on adjusted cox proportional hazards models.
During a median follow-up of 26 years, 63,078 women were diagnosed with breast cancer. We found an increased risk of breast cancer overall among women with PCOS compared with women without PCOS (HR: 1.21, 95% CI 1.02-1.44). In analyses stratified for menopausal status, the increased risk was restricted to postmenopausal women (HR: 1.63, 95% CI 1.23-2.15). The results for ductal and lobular histological subtypes analyses separately resembled those observed for breast cancer overall.
This is the first study to report an increased risk of breast cancer among women with a history of PCOS. The increased risk was seemingly confined to postmenopausal women. Our results therefore contribute to an increased knowledge of the etiology of breast cancer, but our findings should be further confirmed in other large cohort studies with an appropriately long follow-up period.
尽管多囊卵巢综合征（PCOS）的一些生殖和代谢特征是乳腺癌的已知危险因素，但关于 PCOS 与乳腺癌之间潜在关联的证据很少。在这项基于人群的队列研究中，纳入了 1940 年至 1993 年间在丹麦出生的所有 1719452 名女性，我们调查了 PCOS 与乳腺癌之间的关联。
PCOS 诊断、癌症诊断、协变量、迁移和生存状况均从国家人口和健康登记处获得。基于调整后的 cox 比例风险模型，计算了乳腺癌总体和不同组织学亚型的风险比（HR）和 95%置信区间（CI）。
在中位随访 26 年期间，有 63078 名女性被诊断患有乳腺癌。与没有 PCOS 的女性相比，患有 PCOS 的女性乳腺癌总体风险增加（HR：1.21，95%CI 1.02-1.44）。在按绝经状态分层的分析中，这种风险增加仅限于绝经后女性（HR：1.63，95%CI 1.23-2.15）。分别对导管和小叶组织学亚型进行分析的结果与乳腺癌总体观察结果相似。
这是第一项报告有 PCOS 病史的女性乳腺癌风险增加的研究。这种风险增加似乎仅限于绝经后女性。因此，我们的研究结果有助于增加对乳腺癌病因的认识，但需要在其他具有适当长随访期的大型队列研究中进一步证实我们的发现。
