[A survey of primary lung cancer among NTT workers in the Tokyo area. The incidence and mortality during the past 30 years and significance of radiologic screening].

An epidemiological study of primary lung cancer was conducted on NTT workers in the Tokyo area (about 40,000 persons). During the past 30 years (1960-1989), 77 cases (71 males and 6 females) of primary lung cancer were detected by routine medical examination (radiologic screening by radiophotography at their workplaces) or by clinical symptoms, of whom 59 (54 males and 5 females) were dead as of the end of December 1991. Standardized incidence rate and standardized death rate of the males by the direct method (5-yr age groups from 20 to 59 yr of age, per 100,000 population) were 4.5 in the 1960's, 9.9 in the 1970's and 9.8 in the 1980's, and 3.3 in the 1960's, 7.9 in the 1970's and 8.2 in the 1980's, respectively, with increase being observed from the 1970's. Standardized incidence ratio and standardized death ratio of the males by the indirect method (5-yr age groups from 20 to 59 yr of age) were 107 in the 1970's, 86.8 in the 1980's, and 53.8 in the 1960's, 99.4 in the 1970's and 98.5 in the 1980's, respectively. No significant difference could be observed when compared to the national average. By histological type, 44 cases of adenocarcinoma, 12 cases of squamous cell carcinoma, 8 cases of small cell carcinoma, 7 cases of large cell carcinoma and 6 cases of other or unclear types were detected. Excluding the 3 unclear cases, of the 77 cases, 54 cases were peripheral type and the remaining 20 cases were hilar type on radiophotography. Peripheral adenocarcinoma was the most common type.(ABSTRACT TRUNCATED AT 250 WORDS)