Association of Pre-Diagnosis Breast Assessment Practices and Risk Factors with Breast Cancer Stage at Diagnosis: A Single-Center Cross-Sectional Study.

Objective: To describe breast assessment before diagnosis among women with breast cancer (BC) and examine its association with stage at diagnosis. Methods: This single-center cross-sectional study included 191 women with BC attending a medical oncology clinic. Participants completed a face-to-face questionnaire on breast self-examination (BSE), clinical breast examination (CBE), mammography, and patient characteristics. The stage was obtained from medical records. Mammography history was self-reported, and screening mammography could not be distinguished from diagnostic imaging. Exploratory logistic regression compared stage IV with stages I-III. Results: At diagnosis, 41 women (21.5%) had stage IV disease. Regular monthly BSE, regular CBE, and biennial mammography were reported by 8.4%, 3.7%, and 21.4%, respectively. Metastatic disease was present in 7.3% of women who reported biennial mammography and in 25.3% of other women (p = 0.013). In the exploratory multivariable model, biennial mammography was associated with lower odds of metastatic disease (adjusted OR 0.242, 95% CI 0.067-0.869), whereas later menarche was associated with higher odds (adjusted OR 1.273, 95% CI 1.017-1.592). Smoking and hormonal medication use also showed inverse associations, but these findings may reflect confounding or selection and should not be viewed as protective. Conclusions: Self-reported biennial mammography was associated with earlier stage and lower odds of metastatic disease at diagnosis. This cross-sectional study of women with BC cannot establish causality or screening-program effectiveness.