Adjuvant chemotherapy plus radiotherapy is superior to chemotherapy following surgical treatment of stage IIIA N2 non-small-cell lung cancer

The use of additional radiotherapy for resected stage IIIA N2 non-small-cell lung cancer in the setting of standard adjuvant chemotherapy remains controversial. A comprehensive search (last search updated in March 2015) for relevant studies comparing patients with stage IIIA N2 non-small-cell lung cancer undergoing resection after treatment with adjuvant postoperative chemotherapy alone or adjuvant postoperative chemoradiotherapy (POCRT) was conducted. Hazard ratios (HRs) were extracted from these studies to give pooled estimates of the effects of POCRT on overall survival (OS) and disease-free survival (DFS). Six studies were included. The meta-analysis demonstrated that POCRT had a greater OS benefit than postoperative chemotherapy (HR =0.87, 95% confidence interval [CI]: 0.79-0.96, P=0.006). Unfortunately, there was no significant difference in DFS between the two groups: the combined HR for DFS was 0.91 (95% CI: 0.57-1.46, P=0.706). In a subgroup analysis of two randomized controlled trials (n=172 patients), adding radiation was of no benefit to either OS (HR =0.72, 95% CI: 0.49-1.06, P=0.094) or DFS (HR =1.45, 95% CI: 1.00-2.09, P=0.047). In summary, compared with postoperative chemotherapy, POCRT was beneficial to OS but not DFS in patients with stage IIIA N2 non-small-cell lung cancer.