Commonly Prescribed Chronic Pharmacological Medications as Risk Factors for Breast Cancer-Related Lymphedema: An Observational Retrospective Cohort Study.

Background/Objectives: Breast cancer-related lymphedema (BCRL) is a significant complication of breast cancer (BC) treatment, characterized by swelling and fluid accumulation. Many risk factors have already been proven to be related to BCRL; meanwhile, many others are still debated and poorly investigated in the literature. This study investigated the potential involvement of commonly prescribed chronic medications in BCRL development. Methods: This observational retrospective cohort study included 162 post-surgical breast cancer survivors attending an oncological rehabilitation outpatient service between January 2021 and April 2023. BCRL was diagnosed by physicians through clinical evaluation and objective measures (≥2 cm increase in circumferential girth measurements). Descriptive statistics summarized patient characteristics, and Cox regression models (univariable and multivariable) were employed to analyze risk factors for BCRL. Results: BCRL was observed in 53% of participants. The univariable model identified BMI (hazard ratio 1.07, 95% CI 1.02-1.11), overweight (BMI ≥ 25) (HR 1.46, 95% CI 0.95-2.25), and breast prosthesis implantation (HR 1.75, 95% CI 1.09-2.80) as potential risk factors for lymphedema. In the multivariable model, overweight (HR 2.90, 95% CI 1.18-7.14), hypertension (HR 5.09, 95% CI 1.88-13.79), radiotherapy (HR 3.67, 95% CI 1.43-9.38), and breast prosthesis implantation (HR 8.93, 95% CI 2.77-28.81) were identified as independent risk factors for BCRL. Conclusions: The findings emphasize the need for further research to understand the role of chronic medications in BCRL risk comprehensively.