Abstract: | The need of lymph node dissection in the case of operative lung cancer with negative mediastinoscopy was discussed. As a preliminary study, the N-number obtained from the mediastinoscopy and that of postoperative examination was compared. The rate of agreement of N-number was as high as 96%. Secondary, 183 cases of lung cancer with squamous-or adenocarcinoma pathologically T-1 or 2. N-0 and P-0 or 1 were picked up and examined. In those cases, the result of 3 years survival rate was 80% in the cases of absolute curative operation and 60% in that of relative non-curative cases, and 5 years survival rate was 70% and 52% respectively, and the cases of absolute curative operation was statistically excellent than that of another group. However, the background of the two groups was different to some degree on account of the advancement of the cancer and the age of the patients. Therefore, the randomized study as for the lymph node dissection in the cases of negative mediastinoscopy was finally performed. In the 30 cases of squamous cell carcinoma where dissection was carried out in 13 cases and not done in 17 cases, the result of 3 years survival was 84% (dissecting group) and 89% (non-dissecting group), and 5 years survival was 73% and 63% respectively. In 23 cases of adenocarcinoma (13; dissecting, 10; non-dissecting), the result of 3 years survival was 100%, 63% and that of 5 years survival rate was 100%, 63% respectively.(ABSTRACT TRUNCATED AT 250 WORDS) |