We studied 494 patients with lung cancer who had been treated in our hospital from January 1985 through December 1994. Of the total number of cases, 20.4% were stage I; 4.5%, stage II; 12.1%, stage IIIA; 23.8%, stage IIIB; and 34.3%, stage IV. The 5-year-survival rate of patients with non-small cell lung cancer (NSCLC) was 61.0% in stage I, 43.4% in stage II, 21.2% in stage IIIA, 0% in stage IIIB and 0.9% in stage IV. The 3-year-survival rate and median survival time (MST) of patients with small cell lung cancer was 10.3% and 13.7 months in limited disease, and 0% and 4.8 months in extensive disease.
By histologic type, the 5-year-survival rate of patients with NSCLC was 19.7% in squamous cell carcinoma, 19.5% in adenocarcinoma and 5.3% in large cell carcinoma. The 5-year-survival rate of patients who were discovered by health screening was 39.4%; by subjective symptoms, 9.8%; and during the observation of other diseases, 14.7%. The 5-year-survival rate and MST of the patients with NSCLC treated in the Department of Internal Medicine of our hospital (stage III or IV) from 1985 through 1989, and from 1990 through 1994, were 1.9% and 7.4 months in the former period, and 3.7% and 9.9 months in the latter. Approximately 75% of the cases of lung cancer treated in our hospital were stage III or IV disease, and prognosis was very poor. Therefore, prevention and detection in the early stage of lung cancer are important.