[Incidence of lymph node involvement in pN2 non-small cell lung carcinoma and reevaluation of the lymph node dissection method].

We reported post operative survival rate of 134 pN2 squamous cell carcinoma and adenocarcinoma patients in our institute, and analyzed the level of the mediastinal lymph node metastasis to evaluate the standard lymph node dissection method (R2b). Post operative survival rate showed no difference between the left and right lung carcinoma but it showed significant difference between the upper lobe and lower lobe of the both side. Compared with the upper lobe lung cancer, the lower lobe cancer showed higher incidence of metastasis to #7, #8 or #9 lymph node. It is suspected that lymph node dissection of ipsilateral #12 (U), contralateral hilar and #4 lymph node should be considered for the lower lobe cancer especially with #7 lymph node metastasis.