The prognostic nutritional index and postoperative complications after curative lung cancer resection: A retrospective cohort study

Objective: The prognostic nutritional index is a score that represents a patient's immune-nutritional status based on the lymphocyte count and serum albumin concentration. We hypothesized that preoperative prognostic nutritional index is associated with postoperative complications and long-term outcomes after curative resection of lung cancer. Methods: We retrospectively analyzed 1011 patients with pathologic stage I-III adenocarcinoma and squamous cell carcinoma who underwent open thoracotomy for curative resection of lung cancer. The preoperative prognostic nutritional index was calculated as follows based on preoperative laboratory data: 10 × serum albumin (g/dL) + 5 × total lymphocyte count (/nL). The cutoff value of prognostic nutritional index (cutoff value: 50) was obtained by receiver operating characteristics curve and patients were classified as high and low groups. Outcomes were compared with the use of propensity scores and inverse probability weighting adjustment to reduce treatment selection bias. Results: The low group exhibited more postoperative complications (34% [96/285] vs 24% [174/726]; P = .002) especially pneumonia (13% [36/285] vs 6% [41/756]; P < .001) and delirium (10% [29/285] vs 5% [36/726]; P = .002), and greater in-hospital mortality (4% [11/285] vs 1% [9/726]; P = .007) than the high group. A low prognostic nutritional index was associated with greater postoperative pulmonary complications [odds ratio, 1.7; 95% confidence interval, 1.3-2.3], lower recurrence-free survival (hazard ratio, 1.3; 95% confidence interval, 1.1-1.5), and overall survival (hazard ratio, 1.5; 95% confidence interval, 1.2-1.8) after balancing the covariables. Conclusions: The preoperative prognostic nutritional index was associated with postoperative pulmonary complications and long-term outcomes after curative resection of non–small cell lung cancer.