Estrogen receptors in ductal carcinoma in situ of breast.

A number of investigators have suggested treatment of precursor lesions for invasive breast cancer such as ductal carcinoma in situ with antiestrogen. However, very little information is available on the incidence of estrogen receptor in such lesions and the probability of treatment success. Fourteen formalin-fixed tissue specimens of intraductal carcinoma in situ from 14 female patients aged 40 to 66 years were evaluated for the presence of estrogen receptor by immunoperoxidase technique using estrogen receptor antibody. Eight of the 14 lesions (57%) were positive for estrogen receptor. The incidence of estrogen receptor in intraductal carcinoma in situ is very similar to that of invasive carcinoma of breast, leading to the speculation that ER-positive invasive carcinoma originates from ER-positive precursor lesions. Since only 70 per cent of positive receptor lesions are expected to respond to antiestrogens, it appears that only 40 per cent of patients with ductal carcinoma in situ of breast will benefit from endocrine therapy.