Influence of Postoperative Changes in Sarcopenia on Long-Term Survival in Non-Metastatic Colorectal Cancer Patients

SIMPLE SUMMARY: The number of colorectal cancer survivors is increasing due to improvements in oncologic outcomes. Therefore, the risks of metachronous cancer and second cancer are also increased, as well as recurrences. The influence of muscle mass measured as sarcopenia on long-term survival has been studied recently in colorectal cancer patients. Sarcopenia is a factor controllable by lifestyle modification and has gained interest more recently. This study showed an influence of changes in sarcopenia on long-term oncologic outcomes in colorectal cancer and suggests a basis for further investigation of body composition factors, including sarcopenia. ABSTRACT: The effect of perioperative sarcopenic changes on prognosis remains unclear. We conducted a retrospective cohort study with 2333 non-metastatic colorectal cancer patients treated between January 2009 and December 2012 at the Asan Medical Center. The body composition at diagnosis was measured via abdominopelvic computed tomography (CT) using Asan-J software. Patients underwent CT scans preoperatively, as well as at 6 months–1 year and 2–3 years postoperatively. The primary outcome was the association between perioperative sarcopenic changes and survival. According to sarcopenic criteria, 1155 (49.5%), 890 (38.2%), and 893 (38.3%) patients had sarcopenia preoperatively, 6 months–1 year, and 2–3 years postoperatively, respectively. The 5-year overall survival (OS) (95.8% vs. 92.1%, hazard ratio (HR) = 2.234, p < 0.001) and 5-year recurrence-free survival (RFS) (93.2% vs. 86.2%, HR = 2.251, p < 0.001) rates were significantly lower in patients with preoperative sarcopenia. Both OS and RFS were lower in patients with persistent sarcopenia 2–3 years postoperatively than in those who recovered (OS: 96.2% vs. 90.2%, p = 0.001; RFS: 91.1% vs. 83.9%, p = 0.002). In multivariate analysis, postoperative sarcopenia was confirmed as an independent factor associated with decreased OS and RFS. Pre- and postoperative sarcopenia and changes in the condition during surveillance were associated with oncological outcomes.