RESUMEN
A comparative study of estrogen and progesterone receptor bindings of breast carcinoma tissue was done by immunoperoxidase and dextran-coated charcoal (DCC) methods. Fifteen cases of paraffin embedded formalin fixed tissue of mammary carcinomas which had previously been evaluated by the DCC method were selected. Twelve cases were ductal carcinoma and 3 were of lobular origin. Lymph node tissue showing metastasis was available in 3 cases. By immunoperoxidase technique, 12 and 10 (80 and 66.7%) cases were positive for estrogen and progesterone receptor respectively compared with 8 and 3 (53.3 and 20%) cases by the DCC technique. Corresponding results of both methods to detect estrogen and progesterone bindings were 9 and 8 (60 and 53.3%) of all cases, respectively. Five cases for estrogen and 6 cases for progesterone positive by immunoperoxidase could not be detected by the DCC technique. Only one case of estrogen negative by the immunoperoxidase gave a positive result with the DCC technique. Variability of staining occurred between primary and metastatic lesions, 2 out of 3 cases displayed positive staining in both sites; one remaining case was positive only in the lymph node metastasis. Immunoperoxidase is a relatively simple, swift and inexpensive technique in comparison to the DCC technique. Using fixed embedded tissue makes it possible for retrospective studies and providing a permanent record for reevaluation. Moreover, morphology of the tumor can be determined at the same time as detection of hormonal receptor bindings.