Application of prognostic nutritional index in prognostic evaluation of colorectal cancer

Abstract

Objective To investigate the correlation between the prognostic nutritional index(PNI)and clinicopathological features and long-term prognosis of colorectal cancer patients after radical resection. Methods The clinical data of 211 colorectal cancer patients who underwent radical resection was analyzed retrospectively.The PNI value was calculated by serum albumin(g/L)+ 5×lymphocyte count(×109/L). The receiver operating characteristic(ROC)curve and Youden index were used to determine the cutoff value of the PNI.Survival curves were described by the Kaplan-Meier method and compared by the Log-rank test.The univariate and multivariate analysis were performed with the Cox proportional hazard model to identify the prognostic factors. Result The mean PNI value was 43.10±7.09.The mean values of the PNI in age, tumor location, tumor differentiation, tumor depth, negative lymph node, negative metastasis, and TNM staging were significantly higher than those in patients without such factors(all P<0.05). When the PNI was 45, the Youden index was maximal, with a sensitivity of 57.6%and specificity of 79.5%.The mean age in high PNI group were significantly lower than those in low PNI group(χ2=55.464, P<0.001). Tumor located more in rectum in high PNI group(χ2=5.849, P=0.016). Tumor differentiation level in high PNI group was better than that in low PNI group(χ2=4.237, P=0.04). Tumor infiltration depth in high PNI group was less than that in low PNI group(χ2=6.240, P=0.012). The proportion of lymph node metastasis(χ2=13.889, P<0.001)and distal metastasis(χ2=4.490, P=0.034)in high PNI group was were significantly lower than thore in low PNI group.The overall survival rate in high PNI group was higher than that in low PNI group(χ2=27.676, P<0.001). The univariate and multivariate analyses showed that the PNI value<45(OR, 2.083; 95%CI 1.191-3.644; P<0.001)was an independent factor for predicting overall survival rate. Conclusion Prognostic nutritional index is a valuable clinical marker in preoperative estimation as well as prognosis prediction for colorectal cancer. Key words: Colorectal Neoplasms; Nutrition Assessment; Prognosis