The prognostic value of skeletal muscle mass and density in breast cancer: a systematic review and meta-analysis.

Aim: The effect of skeletal muscle mass and density on the long-term survival outcome of breast cancer patients is unclear.Materials & methods: Systematically searched all articles in PubMed, Web of science, Springerlink, EMBASE and Wiley databases that studied the association between skeletal muscle and survival outcomes of breast cancer by 25 September 2023. The hazard ratios and confidence intervals of the multiple factor analysis results controlling for confounding variables in the study were collected and analyzed using STATA 14.0 software.Results: This meta-analysis included a total of 13 studies, with a median age of 48.2 years. Meta results showed that the survival (hazard ratio [HR]: 0.98, 95% CI: 0.89-1.08) and recurrence (HR: 0.96, 95% CI: 0.92-1.00) outcomes of breast cancer patients with sarcopenia were not significantly affected compared with those without sarcopenia. No significant heterogeneity or publication bias was observed in the study.Conclusion: The conclusion that skeletal muscle is regarded as a useful factor that can guide and optimize the prognosis of breast cancer patients is uncertain, or the result is very weak. Considering the impact of research quality and confounding factors, prospective studies are needed in the future to further demonstrate.PROSPERO identifier: CRD42023463480 (www.crd.york.ac.uk/prospero).