Predicting radiation-induced esophagitis in locally advanced NSCLC using baseline clinical factors
Radiation-induced esophagitis (RE) is a common toxicity of thoracic radiotherapy for NSCLC. Pooled analysis of eight phase 2-3 trials (1288 patients) in Japan assessed clinical impact of RE in patients with unresectable stage III NSCLC undergoing concurrent chemoradiotherapy. Grade 2 RE occurred in 15% of patients and grade 3 in 2.0%, Grade ≥ 2 RE was not significantly associated with progression-free survival (PFS, HR 0.98; 95% CI 0.72-1.34) or overall survival (OS; 1.20; 0.82-1.75) whereas grade ≥ 3 RE was associated with worse PFS (1.62; 1.12-2.34) but not OS (1.22; 0.58-2.60). Eight variables independently predicted grade ≥ 2 RE: female sex, T stage ≤ 4, N3 status, adenocarcinoma histology, primary tumor in the left upper lobe, cisplatin use, white blood cell count < 11 x 109/L, and hemoglobin ≤ 12 g/dL The model achieved ad c-statistic of 0.85 (95% CI 0.81-0.88). The authors conlcude that this eight-variable model provides a practical tool for predicting grade ≥ 2 RE and may facilitate tailored supportive care.