Objective To investigate the role of postoperative radiotherapy in the patients treated with curative surgery and adjuvant chemotherapy in stage ⅢA-N2 non-small cell lung cancer (NSCLC).

Methods The clinical data of 313 patients pathologically diagnosed as stage ⅢA-N2 NSCLC with curative resection and adjuvant chemotherapy were retrospectively analyzed. Propensity score matching analysis was used to balance the variables differences. The survival and patterns of failure were observed. The role of postoperative radiotherapy and the subgroups that benefited from postoperative radiotherapy were analyzed.

Results After propensity scores matching, the 3- and 5-year overall survival rates of PORT(+) and PORT(-) were 76.5%, 58.3% and 52.1%, 40.6%, respectively (P=0.162). The 3- and 5-year locoregional control rates of PORT(+) and PORT(-) were 82.9%, 73.7% and 56.5%, 42.4%, respectively (P=0.036). The 3- and 5-year progression-free survival rates of PORT(+) and PORT(-) were 74.8%, 65.5% and 39.5%, 29.6%, respectively (P=0.021). Subgroups analyses suggested that the patients with involvement of subcarinal lymph nodes, tumor diameter≥3cm, multiple N2 metastases, nonskip N2 metastasis and clinical N2 status, and PORT was associated with improved locoregional control rates.

Conclusion PORT could increase the local-regional control rate and progression-free survival rate in stage ⅢA-N2 NSCLC with curative resection and adjuvant chemotherapy; Patients with involvement of subcarinal lymph nodes , tumor diameter≥3cm, multiple N2 metastases, nonskip N2 metastasis and clinical N2 status may benefit most from PORT.