Estrogen receptor concentrations in 269 cases of histologically classified human breast cancer

This report provides a histological review of 264 female primary breast cancers analyzed for estrogen receptor protein (ER). We also describe 5 cases of male breast cancer all of which bound estradiol specifically. Generally the ER concentrations were lower in the tumors of premenopausal women than in those of postmenopausal women. Three types of cancer with specific morphological features were shown to have ER concentrations that differed significantly from the other types of cancer. Medullary and comedo carcinoma had very low and papillary carcinoma very high levels of ER. No obvious trend in ER concentration was found in unspecified ductal carcinoma, colloid carcinoma, nor in lobular carcinoma. A positive correlation was demonstrated between ER content and degree of differentiation in ductal carcinoma. Cancer with lymphoid infiltration generally showed low ER levels.