[Surgical treatment of N2 involved non-small cell lung cancer--the systematic extended lymph node dissection based on the regional lymphatic drainage].

From the study on regional lymphtic drainage, we have decided the extent of lymphadenectomy as follows; a) For the left lung cancer and the right upper lobe primary, systematic bilateral mediastinal dissection (R3 alpha) through a median sternotomy, b) For the cases with the highest mediastinal node involvement, lower half of radical neck dissection (R3 gamma) through a cervical collar incision in addition to a). The cN diagnosis by CT interpretation and pN diagnosis were compared. The under estimated rates of N were 32% of 137 patients with the left lung primary. 46 patients with pN2(+) included 14 patients (31%) with pN3 disease. As for the right upper lobe primary, 17 patients with pN2(+) included 13 patients (76%) with pN3 disease. Postoperative survival rates calculated with Kaplan-Meiermethod; 1) The five-year survival rates were 43% of 46 patients with pT1-3 N2-3 of the left lung primary. 2) As for the right upper lobe primary, the two-year survival rates were 51% of 17 patients with pT1-4 N2-3. 3) The three-year survival rates of 26 patients with pN3 gamma diagnosed as cN0-3 alpha preoperatively were 41%. These systematic extended dissection (R3 alpha, R3 gamma) would bring better prognosis in the patients with pN2-3 disease.