Clinical Features and Prognostic Factor of Thoracic Postoperative Oligo-Recurrence of Non-Small-Cell Lung Cancer

Objective: The study aimed to clarify clinical features and prognostic factors of thoracic oligo-postoperative recurrences that underwent local therapy of non-small-cell lung cancer (NSCLC). Methods: From 2332 patients of resected pathological stage I-IIIA NSCLC between 2008 and 2015, a total of 542 patients in follow developed recurrence. Thoracic oligo-recurrence was defined as 1-3 loco-regional confined to lung lobe, hilar/mediastinal lymph nodes, bronchial stump, or chest wall. This study included 56 thoracic oligo-recurrences. Local therapy included secondary surgery, stereotactic radiotherapy, radiotherapy with a 45 Gy or higher dose, and proton radiation therapy, performed with radical intent. We retrospectively reviewed the postoperative data and performed the univariate and multivariate analysis by Kaplan-Meier methods and Cox regression models, respectively. Results: Thoracic Oligo-recurrence was identified in 56(542,10.3%) patients, mainly in lung lobe(n=22,39%) and regional lymph nodes(n=19,34%). Compared with distant oligo-recurrences, more of the thoracic oligo-recurrences were II-III in pathological stage at initial surgery(p=0.002) and less were adenocarcinoma(p=0.005). The 5-year postoperative survival rate and postoperative progression-free survival rate of thoracic oligo-recurrence were 10.8% and 6.7%, respectively. Median post-recurrence survival (PRS) was 31 months, and the median postoperative progression-free survival (PR-PFS) was 17 months. Multivariate analyses revealed that time to recurrence >/= 12 months was associated with improved PRS [odds ratio (OR) 0.74, confidence interval (CI) 0.65-0.85], and regional lymph node oligo-recurrence was associated with poor PRS [OR 1.48, CI 1.38-1.60]. All the five long-term (>/=5-year) progression-free survivors were with a solitary pulmonary recurrence. Conclusion: Thoracic postoperative oligo-recurrence of non-small-cell lung cancer is a limited but highly heterogeneous population, with different prognosis at different recurrence sites. Local therapy for thoracic oligo-recurrence of NSCLC achieved favourable PRS in a selected population. Pulmonary solitary oligo-recurrence may achieve a long survival time.