The bimodal age distribution of patients with mammary carcinoma.Evidence for the existence of 2 types of human breast cancer

T femaIe subjects with mammary carcinoma was observed in mortality statistics as early as 1930 by von Pirquetl3 and has since been confirmed by morbidity statistics from cancer registries in many European countries and the United States of America.l4,17 The 2 peaks are in the 45-to 49-year age group and at about 65 years of age. As an example, Fig.