Prognostic Value of Sarcopenia in Lung Cancer: A Systematic Review and Meta-analysis

Background Evidence regarding the association between sarcopenia (skeletal muscle depletion) and outcomes in patients with lung cancer varies across studies. We aimed to systematically review the prognostic value of sarcopenia in lung cancer. Methods We searched Ovid MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials through July 23, 2018 to identify retrospective or prospective cohort studies. We applied the Quality in Prognostic Studies instrument to assess the risk of bias in individual studies. We examined the heterogeneity and publication bias and performed subgroup analyses and sensitivity analyses. Results We included 13 studies (1,810 participants). The pooled prevalence of sarcopenia was 43% in patients with non-small cell lung cancer (NSCLC) and 52% in patients with small cell lung cancer (SCLC). Sarcopenia was associated with a shorter overall survival (OS) in patients with lung cancer (hazard ratio [HR], 2.23; 95% CI, 1.68-2.94). This association existed for both NSCLC (HR, 2.57; 95% CI, 1.79-3.68) and SCLC (HR, 1.59; 95% CI, 1.17-2.14). Sarcopenia was an independent predictor of shorter OS in both stage I-II NSCLC (HR, 3.23; 95% CI, 1.68-6.23) and stage III-IV NSCLC (HR, 2.19; 95% CI, 1.14-4.24). However, sarcopenia was not an independent predictor of disease-free survival in patients with NSCLC (HR, 1.28; 95% CI, 0.44-3.69). Conclusions Sarcopenia is highly prevalent in patients with lung cancer (approximately one in two) and an important predictor of impaired OS in patients with SCLC or with different stages of NSCLC.