Objective To explore the correlation of the pan-immune-inflammation value (PIV) and the prognosis of patients with resectable colorectal cancer (CRC) and establish a predictive model.

Methods A total of 753 patients who underwent primary lesion resection and were pathologically diagnosed with CRC were enrolled. They were randomly divided into training (n=527) and test (n=226) cohorts. The best cutoff value of PIV was determined by the time-dependent receiver operator characteristics curve, and patients were divided into high- and low-level groups to analyze the relationship between the high- and low-level groups of PIV and the clinicopathological characteristics and survival of patients. Chi-square test, Kaplan-Meier survival analysis, and Cox regression analysis were used to evaluate the prognosis. The accuracy of the model was evaluated by C index and Brier score.

Results In the univariate model of overall survival (OS), high (> 231) baseline PIV (HR=1.627; 95%CI: 1.155-2.292, P=0.005) suggested that PIV level might be an independent prognostic factor for OS. The nomogram plotted according to PIV had a C index of 0.823. Its calibration curve showed good agreement between predicted and observed outcomes for one- and three-year OS probabilities, with Brier score of 0.035 and 0.068 for OS, respectively.

Conclusion PIV can be used as a prognostic marker in patients with resectable CRC, and a novel prognostic model to guide clinical decision-making in CRC is successfully established.