A Randomized Phase II Study of Adjuvant Concurrent Chemoradiotherapy vs Chemotherapy Alone in Completely Resected Microscopic N2 Non-small Cell Lung Cancer

Approximately 15% of patients with non-small cell lung cancer are diagnosed with stage IIIA-N2 disease. However, this subgroup is heterogeneous, with lymph nodes that are only microscopically invaded to those that are radiologically visible with bulky ipsilateral mediastinal lymph node involvement. Surgical resection in selected patients results in 5-year survival rates of 7-24%. The standard treatment for locally advanced clinical N2 disease is definitive concurrent chemoradiotherapy or induction chemotherapy (± radiation) followed by operation. However, in some patients, N2 status could be confirmed only after curative operation without any evidence of N2 diseases through preoperative evaluation methods (CT, PET, mediastinoscopy). We usually define those N2 disease found only after curative operation as microscopic N2, and do adjuvant chemotherapy, radiotherapy or concurrent chemoradiotherapy. However, little data about the adjuvant therapy for completely resected N2 disease have been available, Hence, we propose a randomized phase II study of adjuvant concurrent chemoradiotherapy vs chemotherapy alone in completely resected microscopic N2 NSCLC.