Incidence of breast cancer in women: a reanalysis

The assumption was made that the incidence of carcinoma of the breast in women was a power function of the age of the population. This produced equations that provided excellent descriptions of the 2 lines obtained (correlation coefficients of 0.98 and 0.99). The "common point" of the 2 equations of incidence versus age was 42 years of age, suggesting that events just prior to menopause may be related to the lower rate of increase of carcinoma of the breast. The dual line description also appears, based on reported mortality data, to be relevant to cancer of the ovary, cervix and corpus uteri in women.