Model for predicting completion of chemoradiotherapy in patients with unresectable stage III non-small cell lung cancer: Analysis of pooled data from a clinical trial database

Concurrent chemoradiotherapy (CCRT) is the standard treatment for unresectable stage III non-small-cell lung cancer (NSCLC). Completion of CCRT affects subsequent therapy and impacts overall survival. The aim of this study was to develop a model for predicting completion of CCRT and thus guide individualized treatment strategies. We conducted a pooled analysis of data from the Japan Lung Cancer Society-Integrated Database, which includes data from eight randomized phase II/III trials of CCRT for unresectable stage III NSCLC in Japan. Clinical factors associated with CCRT completion were identified through multivariable logistic regression analysis and used to develop a scoring model. The scoring model includes neutrophil count ≥4500/μL = two points, C-reactive protein concentration <1.00 mg/dL = two points, cisplatin-based therapy = one point, and PaO 2 ≥83.0 mmHg = one point for a total of six points (NCCP score). NCCP score categories were defined as low (0–3) or high (4–6). Completion rates of CCRT were 39.7% (95% CI = 34.1–45.5%) in the low and 63.9% (95% CI = 56.6–70.7%) in the high NCCP score groups (p < 0.001). High NCCP scores were also significantly associated with better objective response rate, disease control rate, progression-free survival, time-to-treatment failure, and overall survival) ( p <0.001, 0.003, 0.003, <0.001, and <0.001, respectively). The NCCP score, composed of neutrophil count, use of cisplatin, CRP concentration, and PaO 2 , predicts completion of CCRT and may contribute to optimizing CCRT treatment as a supplementary risk stratification in patients with stage III NSCLC.