Background: Obesity has long been considered a risk factor for breast cancer-related lymphedema (BCRL), but the benefits of weight reduction in managing BCRL have not been clearly established.

Objective: To evaluate the beneficial effects of weight loss interventions (WLIs) on the reduction and prevention of BCRL.

Methods: We conducted a systematic review and meta-analysis by searching the PubMed, Scopus, and Embase databases from their earliest record to October 1st, 2019. We included randomized and non-randomized controlled trials involving adult patients with a history of breast cancer, that compared WLI groups with no-WLI groups, and provided quantitative measurements of lymphedema.

Results: Initial literature search yielded 461 nonduplicate records. After exclusion based on title, abstract, and full-text review, four randomized controlled trials involving 460 participants were included for quantitative analysis. Our meta-analysis revealed a significant between-group mean difference (MD) regarding the volume of affected arm (MD = 244.7 mL, 95% confidence interval [CI]: 145.3-344.0) and volume of unaffected arm (MD = 234.5 mL, 95% CI: 146.9-322.1). However, a nonsignificant between-group MD of -0.07% (95% CI: 1.22-1.08) was observed regarding the interlimb volume difference at the end of the WLIs.

Conclusions: In patients with BCRL, WLIs are associated with decreased volume of the affected and unaffected arms but not with decreased severity of BCRL measured by interlimb difference in arm volume.

Keywords: Breast cancer lymphedema; Breast neoplasms; Diet; Exercise; Weight loss.