[Hormone receptor determination in breast carcinoma tissue. Comparison of recent immunohistologic techniques with...

For evaluation of the hormone receptor status in breast cancer tissues two methods are mainly used: immunohistochemical detection by monoclonal antibodies on frozen sections (ER-ICA, PgR-ICA) and the biochemical radioligand-binding assay (DCC) of fresh tissue. Using new antibodies makes it possible to evaluate the estrogen and progesterone receptor status in formalin-fixed and paraffin-embedded tissue. In the present retrospective study, tissues from 223 primary breast carcinomas or breast carcinoma recurrences were re-evaluated with the three methods mentioned above and the results were compared. We used antibody 1D5.26 reacting with the estrogen receptor and mPR1 specific for the progesterone receptor in paraffin-embedded tissue. The agreement of positive and negative cases between these two immunohistochemical procedures was 97.8% for the estrogen receptor and 85.7% for the progesterone receptor. Comparison of immunohistochemistry on paraffin-embedded tissue and biochemical evaluation showed an agreement of 74.7% for the estrogen receptor and 68.7% for the progesterone receptor. These results are comparable to the correspondence between ER-ICA and PgR-ICA and the DCC method. This study proves that the prognostically and therapeutically important hormone receptors can be reliably determined in formalin-fixed and paraffin-embedded tissues. These results are not only important for the evaluation of hormone receptors of a small breast carcinoma that is not found in the frozen section, but for the considerable difference in costs among the different methods.