Aim: Systemic inflammation has been implicated in the progression of patients with colorectal cancer (CRC). We evaluated the prognostic ability of a comprehensive score based on several inflammatory indexes in operable CRC patients.
Patients and Methods: Between July 2013 and September 2017, this study retrospectively identified 1279 CRC patients receiving radical surgery in Wuhan Union Hospital and randomly assigned them into training (N=921) and validation (N=358) sets. A novel score, the CRC-specific inflammatory index (CSII), was developed from a series of inflammatory indexes significantly associated with survival in patients with CRC. This novel score was then divided into three categories and compared to the well-known systematic inflammatory index (SII) and TNM stage. Finally, a survival nomogram was generated by combining the CSII and other informative clinical features.
Results: The CSII-OS was calculated as 1.110×lg ALRI + 1.082×CAR + 0.792×PI, while CSII-DFS was 1.709×lg ALRI + 1.033×CAR based on multivariable Cox regression analysis. Patients with high CSII experienced a worse OS (HR=23.72, 95% CI, 11.30– 49.78, P < 0.001) and worse DFS (HR=15.62, 95% CI, 6.95– 35.08, P < 0.001) compared to those in CRC patients with low CSII. Moreover, ROC analyses showed that the CSII possessed excellent performance (AUC=0.859) in predicting OS and DFS. The AUC of the OS nomogram based on CSII, TNM stage, and chemotherapy was 0.897, while that of the DFS nomogram based on CSII, T stage, and TNM stage was 0.873. High-quality calibration curves in both OS and DFS nomograms were observed. Verification in the validation dataset showed results consistent with those in the training dataset.
Conclusion: The CSII is a CRC-specific prognostic score based on the combination of available inflammatory indexes. High CSII is a strong predictor of worse survival outcomes. The CSII also exhibits better predictive performance compared to SII or TNM stage in operable CRC patients.
Keywords: colorectal cancer, systemic inflammation, prognosis, CRC-specific inflammatory index, survival nomogram