RESUMO
Current data suggest that low skeletal muscle mass provides prognostic information in patients with cancer and may even be considered a biomarker in research and clinical evaluations. The aim of this systematic review was to explore whether low muscle mass is associated with overall survival (OS) in patients with incurable cancer. A systematic search was conducted for published literature using PubMed/MEDLINE, Scopus, LILACS, and the Cochrane Library, with no restrictions on language or publication date, to examine whether low muscle mass is associated with OS in patients with incurable cancer. Eligible studies included low muscle mass evaluated using gold standard techniques (dual energy x-ray absorptiometry or computed tomography). The studies quality assessment was performed using the Newcastle-Ottawa Scale. Thirteen studies were included. The studies reported on 1959 patients between 54.3 (median) and 72.9 (mean) y of age; pancreatic cancer was the most common type of tumor. According to the survival curves and most of the multivariate analyses, there was no statistically significant association between loss of muscle mass and reduced OS. Four studies reported that overweight or obese patients with muscle mass depletion had significantly shorter OS. These results indicate that there is insufficient evidence to associate low muscle mass with OS in patients with incurable cancer. Further studies deploying other muscle measurement methods suggest that use of low muscle mass cutoff alone is still necessary in the pursuit of OS prediction in this population.