[Etiological and histological study of 448 cases of lung cancer (author's transl)].

The study of this series of hospitalized patients extended over a period of 8 years, and the number of cases was estimated to be 1/8 of the total lung cancer population seen in the area serviced by the hospital. Distribution according to sex was in the ratio 18.6/1 and the mean age (60 to 62.8 years) was identical whatever the sex, smoking habits, presence or a absence of exposure to asbestos, and the histological type. The epidermoid type was more frequent, both in men (77.6 p. cent) and women (39.1 p. cent). A significant relationship with smoking was observed in the epidermoid form but not with adenocarcinomas. In men who smoked there were 78.6 p. cent of epidermoids against 53.8 p. cent in women, in whom the percentage of undifferentiated types (15.3 p. cent) exceeded that of the men (5.7 p. cent). In nonsmokers, adenocarcinomas represented 70 p. cent in women against 37.5 p. cent in men. In 9 p. cent of the cancers the patient had been exposed to asbestos during their occupation, the degree of exposure being low or moderate in 78 p. cent. The cancers were more frequently proximal (73 compared with 54.2 p. cent), bilateral (8 compared with 3.4 p. cent), derived from the inferior lobe (superior to inferior lobe ratio: 1.2 to 2.75), more often undifferentiated (20 against 4.2 p. cent), and less frequently of the epidermoid type (65 compared with 80.1 p. cent). The histological type is discussed as a function of the methodology of the histological diagnosis, and of the etiological factors, particular smoking and exposure to asbestos.