Abstract
The bimodal five-year distribution curve of cancer of breast observed in this Institute from January 1970 to May 1976 has been partly explained as a result of a two-peak curve of comedocarcinoma, two unimodal early curve of solid and cribriform carcinoma and a late unimodal curve or « plateau » of papillary carcinoma. The association with the mammary lobules of these tumors is discussed.