Oestrogen receptor activity in intraduct and invasive breast carcinomas

Breast cancers analysed for oestrogen receptor activity over a ten-year period have been surveyed in order to select a group of intraduct carcinomas without invasion and a second, control group of invasive carcinomas without intraduct carcinoma. Examination of histological sections taken from the face of the tumour samples used for receptor analysis showed only 13 purely intraduct carcinomas without any invasion. Each of these was matched for age, menstrual status, hospital of origin, and approximate assay date with two purely invasive ductal carcinomas of no specialized type (26 invasive carcinomas in all).