Prognostic significance of serum creatinine and sarcopenia for 5-year overall survival in patients with colorectal cancer in Korea: a comparative study

Abstract

Purpose: Previous studies have demonstrated that the serum creatinine level and skeletal muscle index (SMI) (correlated with the overall survival [OS] of patients with colorectal cancer [CRC]). However, the combined significance of these 2 factors is not fully understood. The goal of this study was to investigate the prognostic potential of the combination of these two factors in patients with CRC. Methods: The patients were categorized into subgroups based on preoperative serum creatinine level, with a cut-off value of 1.01 mg/dL for males and 0.80 mg/dL for females. The patients were further categorized into 4 groups based on SMI. Data were analyzed using the Cox proportional hazards model and Harrell’s concordance index (C-index). Results: Poor 5-year OS was observed in patients with high SMI and high serum creatinine levels (hazard ratio [HR]=1.676, 95% confidence interval [CI]=1.110–2.529, P=0.013), low SMI and low serum creatinine levels (HR=1.916, 95% CI=1.249–2.938, P=0.002), and low SMI and high serum creatinine levels (HR=2.172, 95% CI=1.279–3.687, P=0.004) compared to those of patients with high SMI and low serum creatinine levels. Grouping patients based on both SMI and serum creatinine levels led to improved prognostic stratification (C-index, 0.626; 95% CI=0.587–0.666) compared to grouping based on SMI (CI difference=0.062, 95% CI=0.031–0.103, P=0.0011) or serum creatinine (CI difference=0.043, 95% CI=0.017–0.081, P=0.0072) alone. Conclusion: Incorporating both SMI and serum creatinine levels enhances the prognostic stratification for 5-year OS in patients with CRC, surpassing the prognostic power of grouping solely based on SMI or creatinine.