Sarcopenia and survival in colorectal cancer without distant metastasis: a systematic review and meta-analysis

Background and Aim: Despite prior attempts to evaluate the effects of sarcopenia on survival among patients with colorectal cancer (CRC), the results of these studies have not been consistent. The present study aimed to evaluate the association between sarcopenia and survival among patients having CRC without distant metastasis by aggregating multiple studies. Methods: We performed a literature search using computerized databases and identified additional studies from among the bibliographies of retrieved articles. The quality of each study was evaluated using the Newcastle–Ottawa Scale, and meta-analyses were performed to evaluate overall survival (OS) and disease-free survival (DFS). Results: Thirteen studies with up to 6600 participants were included in the meta-analyses, with a mean age of 63.6 years (range: 18–93 years). We found that preoperative sarcopenia was associated with worse OS (hazard ratio [HR]: 1.61; 95% confidence interval [CI]: 1.38–1.88) and worse DFS (HR: 1.57; 95% CI: 1.10–2.24). Compared with patients without sarcopenia after tumor resection, those with postoperative sarcopenia had worse OS (HR: 1.76; 95% CI: 1.47–2.10) and DFS (HR: 1.79; 95% CI: 1.46–2.20). Conclusion: These meta-analyses suggest that sarcopenia, no matter observed before or after tumor resection, is associated with worse OS and DFS in patients with CRC who have no distant metastasis.