[Results of surgical treatment of stage I lung cancer]

In this study, survival curves and background factors affecting prognosis of resected stage I lung cancer were reviewed. A total of 735 patients with primary lung cancer, including 288 cases (39.2%) of stage I lung cancer, were surgically treated at Kanazawa University Hospital from January 1973 through September 1989. The cumulative 5-year survival rate after operation for all cases of stage I lung cancer was 61.7%. The background factor which was most concerned with the survival rate was the T factor. The 5-year survival rates according to T factor were as follows: T1N0M0; 74.5%, T2N0M0; 53.8%. There was significant difference of survival rates between them (p < 0.05). Of these 288 cases, 128 cases with adenocarcinoma showed significant prolonged survival when compared to 120 cases with squamous cell carcinoma (p < 0.01). In female patients with stage I lung cancer the 5-year survival rate was significantly better than in male patients with stage I lung cancer (p < 0.01). When the survival rates were compared by ploidy pattern of the primary tumor, patients with diploid tumors showed significantly better survival than those with aneuploid tumors (p < 0.05). It is possible that adjuvant therapy is recommended to improve the survival rate of patients with stage I lung cancer, especially, those in the T2N0M0 classification.