Bronchial cancer - a clinical and pathological study. II. Frequency according to age and sex during a 12-year period.

A necropsy series of bronchial cancer combined with a retrospective clinical study comprising 747 cases of bronchial cancer from a defined population is described. A significant successive increase in the frequency of bronchial cancer during the 12-year period 1958-1969 was found. The increase during three successive 3-year periods will be as much as 45, 86 and 146%, respectively, if the 1958-1960 frequency is set to 100%. In contrast to many other investigations this increase was found in both women and men (the relative increase was exactly the same in both sexes) and for both Group I and Group II tumours. The ratios between men and women and between Group I and Group II tumours in the present material were thus constant throughout the investigation. This may be explained by the assumption that the female population today has smoked cigarettes for a sufficiently long period to stimulate the development of bronchial cancer and that there seems also to be a correlation between Group II tumours and cigarette smoking.