Immunohistochemical evaluation of biological markers in mammary carcinoma in situ: correlation with morphological features and recently proposed schemes for histological classification

In situ carcinoma (CIS) of the breast, particularly of ductal type, is being diagnosed with increasing frequency owing to the widespread use of mammographic screening and there is considerable interest in the prognosis of different histological types of ductal carcinoma in situ (DCIS). Evaluation of biological markers as prognostic indicators in invasive breast carcinomas is well established. Antibodies to many of these markers are now available and immunohistochemical techniques can be applied to in situ as well as infiltrating carcinoma. Definite patterns of marker expression relating to both lobular carcinoma in situ (LCIS) and different morphological types of DCIS are now emerging. Poorly differentiated DCIS, usually of comedo pattern, tends to be oestrogen receptor (ER) and progesterone receptor (PR) negative, nearly always has a high proliferation rate and frequently expresses c-erbB-2 and p53 protein. LCIS and well differentiated DCIS, the latter usually of cribriform or micropapillary pattern, is nearly always ER and PR positive, has a low proliferation rate and rarely, if ever, expresses c-erbB-2 or p53 protein. Biological markers may help in both predicting the outcome of DCIS treated by conservation therapy and in establishing new criteria for histological classification.