Early recurrence factors in patients with stage III non‐small cell lung cancer treated with concurrent chemoradiotherapy

BACKGROUND: The clinical characteristics and risk factors for cancer recurrence have not been well evaluated regarding early recurrence in patients with unresectable locally advanced non‐small cell lung cancer (LA‐NSCLC) who receive concurrent chemoradiotherapy (CRT). The aim of this study was to determine the clinical characteristics and risk factors of patients with stage III unresectable LA‐NSCLC treated with CRT who developed early recurrence. METHODS: We retrospectively reviewed the clinical records of 46 patients diagnosed with stage III unresectable LA‐NSCLC treated with CRT at our center between July 2012 and July 2021. A tumor proportion score (TPS) < 50% was defined as “low expression” and a TPS > 50% was defined as “high expression.” RESULTS: A total of 17 (37.0%) patients had a confirmed recurrence within 1 year of treatment. More patients had a lower body mass index in the early recurrence group than in the later recurrence group (p = 0.038). A higher number of patients in the late recurrence group underwent surgery after CRT (p = 0.036). Patients with a higher TPS were more likely to experience late recurrence than early recurrence (p = 0.001), whereas more patients with stage N3 disease were in the early recurrence group (p = 0.011). Multivariate analysis identified lower TPS expression as an independent risk factor for early recurrence after CRT. Overall survival was prolonged in the late recurrence group (p < 0.001). CONCLUSIONS: A lower TPS may be a predictor of early recurrence after CRT in patients with LA‐NSCLC. These patients should be closely monitored for post‐treatment recurrence.