Failure patterns and oligometastasis after concurrent chemoradiotherapy for stage III-IV non-small cell lung cancer

Objective: To investigate the failure patterns and oligometastasis after concurrent chemoradiotherapy for stage III-IV non-small cell lung cancer (NSCLC), and to discuss the significance of local radiotherapy. Methods: The patterns of failure including oligometastasis were analyzed in 299 previously untreated patients with stage III-IV NSCLC who underwent concurrent chemoradiotherapy from 2007 to 2014. Results: Of all the patients with NSCLC, 88 patients with stage III NSCLC failed, among whom 22(22.7%) experienced primary tumor recurrence with or without distant metastasis and 27(30.1%) experienced oligometastasis, and brain metastasis was the most common failure pattern. A total of 211 patients with stage IV NSCLC failed, among whom 11.4% experienced primary tumor recurrence with or without distant metastasis, 10.0% experienced recurrence of the primary metastatic lesions, and 9.0% experienced new lesions in the organs with metastasis; 9 out of 94 patients with oligometastasis and 12 out of 117 patients without oligometastasis, respectively, experienced recurrence of the primary metastatic lesions. Brain metastasis had the highest incidence rate (38.2%). Conclusions: After concurrent chemoradiotherapy, nearly 1/3 patients with stage III NSCLC and 10% patients with stage IV NSCLC experience the failure of oligometastasis, and brain metastasis is the most common pattern of failure. Radical radiotherapy for primary tumors in stage IV NSCLC can reduce local recurrence. (authors)