Prognostic effect of preoperative Controlling Nutritional Status score in patients with locally advanced rectal cancer: A two-center, retrospective study

This study aimed to identify the prognosis relevant to the Controlling Nutritional Status (CONUT) score in locally advanced rectal cancer patients who were treated with neoadjuvant chemoradiotherapy before radical surgery.

From a retrospective database of 568 patients undergoing radical surgery for rectal cancer at two Chinese institutions between 2012 and 2022, data for 300 patients with locally advanced rectal cancer were identified. The optimal cutoff value for the CONUT score in predicting overall survival (OS) was determined using X-tile software. The associations of the CONUT score with the recurrent metastasis and clinicopathologic parameters were analyzed. The CONUT score's ability to predict OS was also compared with other prognostic markers. Univariate and multivariate Cox regression analysis for OS was performed. Subgroup analysis was conducted to evaluate further the CONUT score's predicting value.

The optimal CONUT score cutoff value was determined as 5 according to X-tile. Patients were divided into CONUT-high (CONUT score ≥ 5) and CONUT-low (CONUT score < 5) groups. CONUT score is significantly correlated with hemoglobin, globulin, and platelets. Time-dependent receiver operating characteristic of the CONUT score predicting OS outperformed all common prognostic markers. Multivariate Cox regression analysis identified CONUT score as an independent prognostic factor for OS (hazard ratio = 5.701; 95% CI, 2.336-13.914; P < 0.001). In the subgroups of age, sex, carcinoembryonic antigen, ypTNM, and tumor response status, significant statistical differences can be observed between CONUT-high and -low.

The present study finds that the preoperative CONUT score may be a useful prognostic indicator in clinical scenarios.