[Surgical results on N2 lung cancer with special reference to correlation between tumor size and extension of lymph node metastases].

Systematic lymph node dissection was performed for every patients undergoing surgical intervention. Since 1981, there were 218 stage IIIA-N2 patients who underwent resection with two operative mortality. The five-year survival rate of whole cases was 22.6%, and that of 152 completely resected cases was 30.0%. Favorable factors on long-term survival of pN2 patients were cN0, T1-2 N2M0, single mediastinal node involvement, and tumor less than 20 mm or less. The five-year survival rates of stage IIIA-N2 patients with tumor diameter of < or = 20 mm, 21-30 mm, 31-50 mm, and > or = 51 mm were 48.1%, 27.7%, 31.2%, and 16.7%, respectively. When micrometastases to lymph node in the p-stage I patients (diagnosed by H-E staining) were examined by immunohistochemical staining, 36 patients (27%) out of 132 verified micrometastases in the lymph nodes.