RESUMEN
PURPOSE: To clarify how body mass index (BMI) affects the development and temporal trend of breast cancer-related lymphedema (BCRL). METHODS: This is a prospective study in which patients with operable breast cancer were registered in a single institute between November 2009 and July 2010. The incidence of lymphedema at 1, 3, and 5 years after surgery was assessed according to BMI, and the trend of newly developed BCRL was examined. Obesity was defined as BMI ≥25 in accordance with the Japan Society for the Study of Obesity. RESULTS: A total of 368 patients were included in this study. The multivariate analysis of the whole population showed that high BMI, axillary dissection, and radiotherapy remained as risk factors for BCRL. Patients with high BMI showed a significantly higher incidence of new lymphedema than those with low BMI at 1 year (p < 00.001) regardless of axillary procedures (39.1 % vs 16.3 % for axillary dissection; 15.6 % vs 1.5 % for sentinel lymph node biopsy) but not at 3 and 5 years. Once BCRL developed, patients with high BMI showed slow recovery and 50.0 % of the patients retained edema at 5 years while patients with low BMI showed rapid recovery and 26.7 % retained after 3 years (p = 0.04). CONCLUSION: The preoperative BMI affected the incidence and temporal trend of BCRL regardless of axillary procedures or radiotherapy. Patients with high BMI should be given appropriate information about BCRL before surgery with careful follow-up for BCRL after treatment.