Prediction of postoperative pulmonary complications using preoperative controlling nutritional status (CONUT) score in patients with resectable non-small cell lung cancer

Abstract

Postoperative pulmonary complications (PPCs) significantly impact surgical outcome. We investigated the predictive ability of controlling nutritional status (CONUT) for PPC after lung resection in patients with non-small cell lung cancer (NSCLC). We retrospectively reviewed data of 922 patients with NSCLC who underwent complete resection from January 2016-December 2017. We analyzed the frequency and characteristics of PPCs and compared receiver operating characteristic (ROC) curves of various prognostic models to predict PPCs. A CONUT score higher than 1 was considered as a high CONUT score. Total incidence of PPCs was 8.6% (n = 79). The proportion of pneumonia was significantly larger in the high CONUT group (P < 0.05). The CONUT consistently had a higher area under curve (AUC) value (0.64) than other prognostic models (prognostic nutritional index (PNI): AUC = 0.61, Glasgow prognostic score (GPS): AUC = 0.57, and assessment of respiratory risk in surgical patients in Catalonia (ARISCAT): AUC = 0.54). Multivariate analysis identified underweight [Odds ratio (OR) = 4.57, P = 0.002] and high CONUT score (OR = 1.91, P = 0.009) as independent PPCs prognostic factors. One-year mortality rate for high CONUT score was significantly higher (hazard ratio = 7.97; 95% confidence interval, 1.78-35.59). Preoperative CONUT score is an independent predictor of PPCs and 1-year mortality in patients with resectable NSCLC.

Figure 1

Frequency distribution of CONUT scores and comparison of the area under the ROC curve for PPCs predictability of the CONUT depending on different cut-off values. (A) Distribution of the study population depending on CONUT score. Approximately half of the study population had a CONUT score of 0 or 1 (452 of 922, 49.0%). (B) ROC curves for PPCs according to the various cut-off values of CONUT. The AUCs were 0.594 (CONUT > 0), 0.642 (CONUT > 1), 0.601 (CONUT > 2), and 0.591 (CONUT > 3). AUC area under curve, CONUT controlling nutritional status, PPCs postoperative pulmonary complications, ROC receiver operating characteristic, CI confidence interval.

Figure 2

Comparison of the area under the ROC curve for PPCs predictability of the CONUT and inflammation-based prognostic scores/ARISCAT score. The ability of various preoperative risk assessment scores to predict PPCs was compared using ROC curve. The AUC of the CONUT, PNI, GPS, and ARISCAT were 0.64 (95% CI 0.63–0.69), 0.61 (95% CI 0.58–0.65), 0.57 (95% CI; 0.54–0.60) and 0.54 (95% CI 0.51–0.57), respectively. The AUC of the CONUT was significantly higher than that of the GPS (P = 0.01) and the ARISCAT (P < 0.01). ARISCAT assessment of respiratory risk in surgical patients in Catalonia, AUC are under curve, CONUT controlling nutritional status, GPS Glasgow prognostic score, PNI prognostic nutritional index, PPCs postoperative pulmonary complications, ROC receiver operating characteristic, CI confidence interval.

Figure 3

Kaplan–Meier survival curves according to CONUT status of (A) all subjects, (B) subjects with PPCs. One-year mortality was higher in the high CONUT group than in the low CONUT group, both in whole study population (P < 0.001; A) and among the 79 patients with PPCs (P = 0.028; B). CONUT controlling nutritional status, PPCs postoperative pulmonary complications