Weight loss does not decrease risk of breast cancer-related arm lymphedema.

BACKGROUND: The goal of this study was to determine the relationship between postoperative weight change and breast cancer-related lymphedema (BCRL). METHODS: In this cohort study, 1161 women underwent unilateral breast surgery for breast cancer from 2005 to 2020 and were prospectively screened for BCRL. Arm volume measurements were obtained via an optoelectronic perometer preoperatively, postoperatively, and in the follow-up setting every 6 to 12 months. Mean follow-up from preoperative baseline was 49.1 months. The main outcome was BCRL, defined as a relative volume change of the ipsilateral arm of ≥10% at least 3 months after surgery. RESULTS: A total of 92 patients (7.9%) developed BCRL. Net weight loss versus net weight gain from baseline to last follow-up was not protective against developing BCRL (hazard ratio, 1.38; 95% confidence interval, 0.89-2.13; P = .152). CONCLUSIONS: Although weight loss may be recommended as part of an individualized lifestyle management program for overall health, weight loss alone may not decrease the risk of developing BCRL.