Low Prognostic Nutritional Index Predicts Poor Clinical Outcomes in Patients with Stage IIIB Non-small-cell Lung Carcinoma Undergoing Chemoradiotherapy

PURPOSE: To investigate the prognostic utility of the prognostic nutritional index (PNI) in stage IIIB non-small-cell lung carcinoma (NSCLC) patients undergoing concurrent chemoradiotherapy (CRT). METHODS: A total of 358 stage IIIB NSCLC patients who received a total dose of 60–66 Gy (2 Gy/fraction) radiotherapy and ≥1 cycle(s) of platinum-based chemotherapy were analyzed. The receiver operating curve analysis was utilized to identify the optimal PNI cut-off value demonstrating a significant connection with the overall survival (OS), locoregional progression-free survival (LRPFS), and progression-free survival (PFS). RESULTS: At a median follow-up time of 22.5 months (range: 2.4–123.5), 30.2% and 14% of the patients were still alive and free of disease progression, respectively.The median OS, LRPFS, and PFS were 25.2 [95% confidence interval (CI): 36.3–46.6 months], 15.4 (95% CI: 26.6–35.3 months), and 10.7 (95% CI: 36.8–69.9 months), individually, for the whole study accomplice. The ROC analysis revealed an optimum rounded cut-off that associated meaningfully with each of the OS [area under the curve (AUC): 84.1%; sensitivity: 75.9%;72.4% specificity], LRPFS (AUC: 92.4%; sensitivity: 87.9%; 85.1% specificity), and PFS (AUC: 80.1%; sensitivity: 73.7%; 71.6% specificity) at a value of 40.5. Comparative analyses revealed that the patients presenting with PNI≤40.5 had significantly inferior OS (16.8 vs 36.7; P<0.001), LRPFS (11.5 vs 19.5; P<0.001), and PFS (8.6 vs 13.6; P<0.001) outcomes compared to patients with PNI>40.5. In univariate analyses, lower T-stage (1–2 vs 3–4; P< 0.001), lower N-stage (N2 vs N3; P< 0.001), anemia status (absent vs present; P< 0.001), weight loss status (<5% vs ≥5%; P< 0.001), and PNI group (≤40.5 vs >40.5; P<0.001) were the factors found to be associated with OS, LRPFS and PFS results. The results of multivariate analysis exhibited that the PNI was independently associated with each of the OS (P<0.001), LRPFS (P<0.001), and PFS (P<0.001) outcomes. CONCLUSION: The pretreatment PNI appears to be a robust novel prognostic factor that stratifies patients with stage IIIB NSCLC into two significantly distinct survival groups after CRT.