Induction chemoradiation is not superior to induction chemotherapy alone in stage IIIA lung cancer

Background: The optimal treatment strategy for patients with operable stage IIIA (N2) non-small cell lung cancer is uncertain. We performed a systematic review and meta-analysis to test the hypothesis that the addition of radiotherapy to induction chemotherapy prior to surgical resection does not improve survival compared with induction chemotherapy alone. Methods: A comprehensive search of PubMed for relevant studies comparing patients with stage IIIA (N2) non-small cell lung cancer undergoing resection after treatment with induction chemotherapy alone or induction chemoradiotherapy was conducted using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) standards. Hazard ratios were extracted from these studies to give pooled estimates of the effect of induction therapy on overall survival. Results: There were 7 studies that met criteria for analysis, including 1 randomized control trial, 1 phase II study, 3 retrospective reviews, and 2 published abstracts of randomized controlled trials. None of the studies demonstrated a survival benefit to adding induction radiation to induction chemotherapy versus induction chemotherapy alone. The meta-analysis performed on randomized studies (n = 156 patients) demonstrated no benefit in survival from adding radiation (hazard ratio 0.93, 95% confidence interval 0.54 to 1.62, p = 0.81), nor did the meta-analysis performed on retrospective studies (n = 183 patients, hazard ratio 0.77, 95% confidence interval 0.50 to 1.19, p = 0.24). Conclusions: Published evidence is sparse but does not support the use of radiation therapy in induction regimens for stage IIIA (N2). Given the potential disadvantages of adding radiation preoperatively, clinicians should consider using this treatment strategy only in the context of a clinical trial to allow better assessment of its effectiveness.