[The relationship between the pathways of the lymphatic drainage into the mediastinal nodes and the survival rate for N2 lung cancers underwent curative resection].

The pathways of the metastases to the mediastinal nodes were determined in each case of 68 N2 lung cancer patients undergoing mediastinal lymph node dissection. The relationship between the pathways of the metastases and the survival rate was examined in the 57 N2 lung cancer patients undergoing curative resection. The results were as follows: (1) The direct metastatic passage to the mediastinal nodes was observed in 32.1% in the right upper lobe. The survival rate of this group was 55.4% (4-year survival rate), and that of cases metastasized to the intrapulmonary and/or hilar nodes as well as mediastinal nodes was 42.4% (3-year survival rate). (2) The dominant lymphatic drainage from the middle lobe and the lower lobes flowed into the subcarinal nodes through the hilar nodes. 75% had involvement of the subcarinal nodes, and 33.3% had involvement of the upper mediastinal nodes. 5-year survival rate of the cases without the upper mediastinal nodes metastases was 59.0%, and that of cases metastasized to the upper mediastinal nodes was 26.7% (3-year survival rate). (3) The dominant lymphatic drainage from the left upper lobe flowed into the subaortic or paraaortic nodes. 5-year survival rate in the left upper lobe was 50.0%. It suggested that the cases metastasized to the mediastinal nodes via the direct passage in the right upper lobe, the cases in the left upper lobe, and the cases metastasized to the subcarinal nodes without the upper mediastinal nodes metastases in the middle lobe and the lower lobes had better prognosis.