BACKGROUND: The optimal treatment for stage IIIA-N2 non-small cell lung cancer (NSCLC) is controversial. We aimed to address this important issue through a Bayesian network meta-analysis.

METHODS: We performed a search of electronic databases for randomized controlled trials comparing the following treatments: surgery, radiotherapy, chemotherapy, and their multiple combinations before March 25, 2018. Pooled data on overall survival and treatment-related deaths were analyzed within the Bayesian framework.

RESULTS: Eighteen eligible trials reporting 13 treatments were included. In terms of overall survival, neoadjuvant chemotherapy followed by surgery and adjuvant chemotherapy or radiotherapy, which tended to be consistent (hazard ratio [HR] 1.14, 95% credible interval [CrI] 0.21 to 5.93), ranked superior to other treatments. Notably, neoadjuvant chemotherapy followed by surgery and adjuvant radiotherapy was significantly more effective in prolonging survival than surgery alone (HR 0.38, 95% CrI 0.18 to 0.81), surgery plus adjuvant radiotherapy (HR 0.51, 95% CrI 0.29 to 0.92) and potentially surgery plus adjuvant chemotherapy (HR 0.49, 95% CrI 0.23 to 1.05). Overall, with 29% as the highest possibility of causing the fewest treatment-related deaths, neoadjuvant chemotherapy followed by surgery and adjuvant chemotherapy or radiotherapy was the safest treatment option.

CONCLUSIONS: Neoadjuvant chemotherapy followed by surgery and adjuvant chemotherapy or radiotherapy has the greatest possibility to be the optimal treatment with the best overall survival and fewest treatment-related deaths for stage IIIA-N2 NSCLC.