Abstract
BACKGROUND: Breast cancer is the most commonly diagnosed cancer among women worldwide, and it is associated with significant number of metabolic and reproductive risk factors. Despite the overlap between hormonal and metabolic factors involved in the development of PCOS and many known risk factors for breast cancer, the relationship between PCOS and breast cancer, the most common type of cancer among women, remains unknown. This study was conducted with the aim of determining the relationship between breast cancer and clinical symptoms of PCOS. METHODS: This case-control study was conducted on 285 women with breast cancer and 285 healthy women referred to three centers in Tehran in 2023. Both the case and control groups were matched in terms of age and body mass index. The data collection tool in this study was a researcher-made data registration form, that was completed in person by qualified individuals. A history of PCOS was identified according to the Rotterdam criteria. Women aged 15-49 years who were able to read and write were included in the study. The case group had a history of breast cancer, while the control group did not. Participants who did not consent to having their data use in the analysis were excluded. Data was analyzed using an independent t-test, a chi-square test and a logistic regression model. RESULTS: The mean age of the participants in the case group was 43.05 ± 4.92 years and that of the control group was 42.78 ± 5.06 years. The two groups showed a statistically significant difference in terms of PCOS history (p < 0.001). After adjusting for confounding variables, the logistic regression model showed that women with PCOS had a significantly higher chance of developing breast cancer (0R: 3.677, 95%CI: 1.529-8.840, P = 0.004). Among PCOS symptoms, women with a history of hirsutism had a higher chance of developing breast cancer (OR: 2.188, 95% CI: 1.014-4.720, P = 0.046). CONCLUSION: The findings of the present study suggest that PCOS is a risk factor for breast cancer. Well-designed further studies are highly recommended to determine the role of PCOS in predicting breast cancer.