Prognostic significance of a novel index score based on the inflammation‐based prognostic scores of patients with colorectal cancer

Background and Aim This study aimed to clarify the prognostic value of various inflammation‐based prognostic scores (IBPSs) in patients who underwent radical surgery for colorectal cancer (CRC) and to develop a novel prognostic index using IBPSs and other predictive factors. Methods Data of 1157 patients who underwent radical surgery for CRC were reviewed. The predictive value of various IBPSs in determining the CRC prognosis was compared. A novel index score based on the IBPSs and other parameters that were associated with survival in patients with CRC was established, and its usefulness was evaluated. Results The patients were randomly divided into the training ( n = 694) and validation ( n = 463) sets. Male sex ( P = 0.0001), age ≥ 75 years ( P < 0.0001), a carcinoembryonic antigen (CEA) level of > 5 ( P = 0.0009), a C‐reactive protein/albumin ratio (CAR) of ≥ 0.04 ( P = 0.0033), and a prognostic nutritional index (PNI) of < 43.1 ( P = 0.0004) were poor independent prognostic factors of overall survival. The novel index score was calculated based on the scores of these five prognostic factors. The Kaplan–Meier survival curves showed that the CRC patients with higher novel index scores in the training and validation datasets had poorer overall survival. Conclusions CAR and PNI were superior to other IBPSs for predicting the prognosis of CRC patients. The novel index score established based on sex, age, CEA level, CAR, and PNI can predict the prognosis of CRC with more precise and clearer stratification than the individual parameters alone.