Preoperative Controlling Nutritional Status(CONUT) as an optimal prognostic nutritional index to predict the long-term outcome after radical surgery for colorectal cancer

Abstract Background Controlled nutritional status (CONUT) can effectively reflect the nutritional status of the body, which is closely related to cancer prognosis. The purpose of this study was to investigate the relationship between the CONUT score and prognosis after radical surgery for colorectal cancer, and to compare the predictive ability of the CONUT score with other indexes. Methods A retrospective analysis included 217 patients with newly diagnosed colorectal cancer was performed. The CONUT score was calculated based on the serum albumin level, total lymphocyte count, and total cholesterol level. The cutoff value of the CONUT score for predicting prognosis was 4 according to the Youden Index by Receiver operating characteristic curve. The associations between the CONUT score and the prognosis were performed by Kaplan-Meier curves and Cox regression analysis. Results Stratified by the cutoff value of the CONUT score, patients were divided into CONUT LOW group(n = 189) and CONUT HIGH group (n = 28). CONUT HIGH group had worse overall survival(p = 0.013) and Replase-free survival(P = 0.015). The predictive performances of CONUT were superior to NLR, mGPS and PNI. Meanwhile, the predictive performances of CONUT + TNM stage for 3-year OS (AUC = 0.803) and 3-year RFS (AUC = 0.765) were no less than SMI + TNM stage. The CONUT score was negatively correlated with SMI(p<0.01). Conclusions The CONUT score as a nutritional indicator could predict long-term outcome after radical surgery for colorectal cancer, and its predictive ability was superior to other indexes. The correlation between the CONUT score and skeletal muscle may be one of the factors that play a predictive role.