A promising prediction model for survival in gallbladder carcinoma patients: pretreatment prognostic nutrient index

The pretreatment nutritional and immunological status play indispensable roles in predicting the outcome of patients with various types of malignancies. The aim of the study was to investigate whether preoperative prognostic nutritional index (PNI), which simply accounts for nutritional and immunological status, was associated with overall survival (OS) in patients with gallbladder carcinoma (GBC). The retrospective study included a total of 315 GBC patients after surgery between 2002 and 2012. PNI was calculated according to the following formula: 10× serum albumin (g/dl) +0.005× total lymphocyte count (per mm³). A receiver operating characteristic (ROC) curve for survival prediction was plotted to verify the optimal cutoff value for LMR, which was set at 46.14. According the value, patients were categorized into two different groups, namely high-PNI group (n = 133) and low-PNI group (n = 182). The univariate and multivariate Cox regression models were used to identify the independent prognostic factors. The results showed that low pretreatment PNI value was significantly associated with elderly age, partial surgery procedure, and advanced tumor status such as tumor stage, node stage, and tumor-node-metastasis stage (P < 0.05). The low-PNI group had a worse OS compare with the high-PNI group (P < 0.05). Via univariate and multivariate analyses, pretreatment PNI was identified as an independent prognostic factor for OS [HR: 0.613; 95%CI: 0.448-0.838; P < 0.001]. Subgroup analyses further revealed that PNI was significantly associated with postoperative OS independent of tumor node metastasis stage and surgical procedure. In conclusion, pretreatment PNI might serve as an effective predictor to evaluate prognosis of GBC patients after surgery. Based on the findings, PNI, characterized with accessibility, objectivity and noninvasiveness, should be included in the routine assessment of GBC.