Low muscle mass-to-fat ratio is an independent factor that predicts worse overall survival and complications in patients with colon cancer: a retrospective single-center cohort study.

Purpose: This study was performed to investigate influencing factors of preoperative muscle mass-to-fat ratio (MMFR) and its impact on overall survival and postoperative complications of colon cancer.

Methods: Patients who underwent colectomy for stage I-III colon cancer at the Second Affiliated Hospital of Soochow University between January 2016 and December 2022 were included. The skeletal muscle and fat area at the third lumbar vertebra were measured with preoperative CT measurement. MMFR was defined as the ratio of skeletal muscle area to total fat area, and low MMFR was defined as the 2 lowest tertiles (≤0.585). Univariate and multivariable analyses were conducted to assess the impact of MMFR on overall complications and survival outcomes. Kaplan-Meier survival curves and log-rank test were used to compare the overall survival between high MMFR and low MMFR groups.

Results: A total of 885 patients were analyzed. Female sex, older age, high body mass index, sarcopenia, and high cancer stage were more likely to result in low MMFR. Complications, including intestinal fistula, chylous fistula and organ space surgical site infection were significantly higher in the low MMFR group. Low MMFR was an independent factor associated with overall complications (odds ratio, 1.940; 95% confidence interval [CI], 1.252-3.007; P < 0.01) and long-term survival (hazard ratio, 2.222; 95% CI, 1.443-3.425; P < 0.01). Furthermore, patients with high MMFR had a higher survival rate than patients with low MMFR (P < 0.01).

Conclusion: Low MMFR is an independent factor that predicts worse overall survival and complications in patients with colon cancer.