Factors influencing survival and recurrence and potential significance of postoperative radiotherapy and adjuvant chemotherapy for stage ⅢA-N2 non-small cell lung cancer

Abstract

Objective: To investigate the survival, recurrence patterns and risk factors in patients with stage ⅢA-N2 NSCLC treated with curative surgery and adjuvant chemotherapy and to explore the significance of postoperative radiation therapy. Methods: The clinical data of 290 patients with pathologically diagnosed stage ⅢA-N2 NSCLC after curative resection and adjuvant chemotherapy from January 2010 to December 2014 at our department were retrospectively analyzed. The survival and recurrence patterns were observed, and the factors affecting locoregional recurrence were analyzed. Results: The median survival time was 31.5 months. The 1-, 3-and 5-year survival rates were 88.3%, 46.0% and 33.2%, respectively. The median locoregional control time was 38.5 months. The 1-, 3-and 5-year locoregional control rates were 78.6%, 55.2% and 41.0%, respectively. The median distant metastasis-free survival was 26.8 months. The 1-, 3-and 5-year distant metastasis-free survival rates were 76.4%, 45.5% and 39.5%, respectively. The median progression-free survival was 19.1 months. The 1-, 3-and 5-year progression-free survival rates were 64.1%, 32.5% and 23.8%, respectively. Univariate analysis showed that clinical N status, histological type, pathological T stage, operation mode, the number of positive N2 lymph nodes and the number of positive N2 lymph node stations had a significant influence on overall survival; clinical N status, histological type, the number of positive N2 lymph nodes and the number of positive N2 lymph node stations had a significant influence on locoregional control. Multivariate analysis demonstrated that the number of N2 positive lymph nodes (P= 0.017) was an independent factor for overall survival of stage ⅢA-N2 patients; the number of N2 positive lymph nodes (P=0.009) and histological type (P=0.005) were independent factors for locoregional recurrence. For left-sided lung cancer, the lymph node station failure sites were mostly in 2R, 4R, 5, 6 and 7, and the contralateral mediastinum was frequently involved. For right-sided lung cancer, the lymph node station failure sites were mostly in 2R, 4R, 7, 10R and surgical stump. Conclusions: Clinical N2, squamous cell carcinoma, positive N2 nodes of more than 3 and multiple positive N2 stations are poor prognostic factors for locoregional recurrence. Locoregional recurrence of left lung cancer frequently involves the contralateral mediastinum, while that of the right lung cancer usually locates in the ipsilateral mediastinum.