Receptors for estrogen and progesterone in breast carcinoma in situ.

In contrast to the situation in invasive breast carcinoma, there are only few reports on the levels of receptors for estrogen (ER) and progesterone (PgR) in pre-invasive (in situ) breast carcinoma. In the present study ER and PgR levels were analyzed in 57 in situ human mammary carcinomas using a quantitative enzyme immunoassay method. Intraductal carcinoma was the dominating histopathological subgroup (75%). Within this subgroup the non-comedo and comedo variants comprised 66 and 34 percent respectively. Intralobular and papillary in situ subtypes were the second most frequent subgroups, representing 11% each. Using a cut-off level of 0.05 fmole/microgram DNA to define receptor poor and rich tumors we found that thirty-one out of the 57 cases (54%) were ER-rich. In the ER-rich tumors the receptor levels varied between 0.05 and 6.50 fmole/microgram with a mean concentration of 0.80 fmole/microgram DNA. Fifteen of 51 (30%) tumors were classified as PgR-rich tumors in which the levels ranged between 0.05 and 2.90 fmoles/microgram DNA, with a mean concentration of 0.45 fmoles/microgram DNA. Two thirds of the non-comedo, lobular and papillary variant were ER rich. A majority (80%) of comedo tumors were ER poor. Our findings show that 54% of in situ breast carcinomas have the molecular prerequisites for response to antiestrogen therapy which is of interest when planning adjuvant treatment protocols.