Abstract Purpose Identifying risk factors for breast cancer-related lymphedema (BCRL) is crucial for its prevention, necessitating large-scale epidemiological studies. Despite their suitability for large-scale surveys, to our knowledge, databases have not been the basis of any study done to investigate BCRL risk factors. This study aimed to test the hypothesis that a database-based study would be useful for identifying BCRL risk factors. Methods Patients with breast cancer diagnosed between April 2009 and March 2020 were identified from the Hiroshima University Hospital’s medical database. This retrospective observational study validated the risk factors for BCRL using logistic regression analysis ( p &lt; 0.05). Results Among the total 4471 breast cancer patients identified, 2359 met the study criteria, with a BCRL incidence of 4.8%. Identified risk factors included obesity with a BMI of 25–30 (OR = 3.066, 95% CI 1.408–6.677), severe obesity with a BMI &gt; 30 (OR = 5.791, 95% CI 2.239–14.97), surgical axillary lymph node dissection (OR = 3.212, 95% CI 1.918–5.378), chemotherapy with docetaxel (OR = 1.795, 95% CI 1.062–3.032), and conventional radiation to the breast or chest wall including lymph nodes in the irradiated area (OR = 3.299, 95% CI 1.842–5.910). Conclusions The BCRL risk factors identified by our database analysis were in line with those documented in previous studies, indicating the usefulness of database-based studies. Future studies should include more patients and study items.

Database study of risk factors for breast cancer-related lymphedema: a statistical analysis of 2359 cases over 10 years