Immunohistochemical assessment of estrogen and progesterone receptors in stored imprints and cryostat sections of breast carcinomas.

A peroxidase-antiperoxidase technique was used to visualize estrogen and progesterone receptors in stored imprints and cryostat sections of breast carcinomas that were prepared at the time of biopsy or frozen section diagnosis. This was done to provide an alternate technique for the assessment of the receptor status of tumors that could not be adequately assayed with other biochemical or immunocytological methods. Fixation in Zamboni's fixative followed by passage through cold methanol and acetone before storage at -80 C insured good preservation of the receptor proteins over extended periods of time (up to 56 weeks). Immunostaining of these stored preparations with monoclonal antibodies against estrogen receptor (H222) and progesterone receptor (JZB39 and KD68) showed a high degree of correspondence with immunocytochemical assays (ER-ICA and PR-ICA) and biochemical analysis. This technique is easy to perform and provides reliable information, even in tumors that are too small and/or ill defined to permit separate sampling for receptor assays.