Predictive value of prognostic nutritional index on infection after radical gastrectomy: a retrospective study

The prognostic nutritional index (PNI) is a useful tool to evaluate nutritional status, which is associated with postoperative complications and prognosis of patients with cancer. Recent studies have shown that PNI has important predictive value for postoperative infection in cancer patients. However, the role and clinical value of PNI in infection after radical gastrectomy remains unclear. This study investigated the relationship between PNI and infection after radical surgery for gastric cancer (GC), focusing on the predictive value of PNI.

A total of 1,111 patients with primary gastric cancer who underwent radical surgery in our hospital from December 2010 to December 2020 were included in this retrospective study. The demographic and clinicopathological data of all patients were acquired through hospital information system (HIS). Preoperative serum albumin (ALB) level and peripheral blood lymphocyte count were obtained for PNI calculation. We selected 812 patients by propensity score matching to reduce biases due to the different distributions of co-variables among the comparable groups. The factors influencing postoperative infection in the matched patients were explored using univariate and multivariate analyses.

Baseline characteristics significantly differed among patients with different PNI scores. After one-to-one matching, the clinicopathological data of the 2 groups were comparable, and 812 patients were included for further analysis. Among these patients, 101 developed infections, with an infection rate of 12.4%, which were mainly caused by gram-negative bacteria. The incidence of infection was significantly higher in the low PNI group than in the high PNI group. Univariate and multivariate analyses identified body mass index (BMI) ≥25 kg/m² [odds ratio (OR) =2.314, P=0.004], diabetes mellitus (OR =1.827, P=0.042), PNI score <45 (OR =2.138, P=0.037), combined multi-organ resection (OR =2.946, P<0.001), operation time ≥240 minutes (OR =2.744, P=0.023), and perioperative blood transfusion (OR =2.595, P=0.025) as risk factors for infection after radical surgery for GC.

Infection is the most common complication after radical gastrectomy for GC, and a low preoperative PNI score is a risk factor for postoperative infection.