Investigating The Effects of The Model Covariates on Breast Cancer Risk Using the Knapp-Hartung Adjusted Random-Effects Meta-Regression

Background: Breast cancer is a leading cause of cancer-related morbidity and mortality among women worldwide. Reproductive and familial factors are known to influence breast cancer risk, but their effects vary across studies. This study aimed to investigate the impact of selected covariates on breast cancer risk using a Knapp–Hartung adjusted random-effects meta-regression. Methods: A random-effects meta-regression analysis was conducted using data from 60 samples. The model assessed the associations between breast cancer risk and age at menarche, history of breastfeeding, age at menopause, and family history of cancer. The Knapp–Hartung adjustment was applied to account for uncertainty in between-study variance. All statistical analyses were performed using R software. Results: Ever breastfed was significantly associated with a reduced risk of breast cancer (coefficient = ?0.4135, p = 0.001), Menopause (coefficient = 0.1082, p = 0.024) and family history of cancer (coefficient = 0.2435, p = 0.015) were significantly associated with increased breast cancer risk. Menarche demonstrated a positive but borderline significant association with breast cancer risk (coefficient = 0.1116, p = 0.063). Conclusion: Breastfeeding appears to confer a protective effect against breast cancer, whereas menopause and family history of cancer are associated with elevated risk. These findings emphasize the importance of reproductive and familial factors in breast cancer risk evaluation and prevention strategies.