Immunohistochemical evaluation of hormone receptors with predictive value in mammary carcinomas

AIMS. Immunohistochemical evaluation of hormone receptors (ER, PR) and correlation of immunohistochemical and morpho-clinical data. METHOD. The study was performed on paraffin-embedded and HE stained tissues originating from 100 cases of invasive mammary carcinoma. Monoclonal antibodies anti-estrogen and anti progesterone receptors were used for the immunohistochemical study. The detection system was EnVision HRP and the visualization system was 3-3' diaminobenzidine tetrahydrochloride (DAB). The evaluation of the result was performed using the Allred score. REZULTS. The majority of the studied cases (57%) expressed both types of hormone receptors and in 32% of the cases the hormone receptors were completely absent. The rest of the cases presented a heterogeneous phenotype: 7% presented the ER-/PR+ type and 4%, the ER+/PR- type. Compared with the classical phenotype (ER+/PR-), ER+/PR- tumors were more frequent at patients over 50 years. The tumors with ER+/PR- were larger than the ER+/PR+ and they were of the invasive ductal carcinoma type with an Allred score for ER under 6. CONCLUSION. The predictive value is amplified when the ER status is correlated with the PR status because the heterogeneous phenotypes are identified, especially the ER+/PR- phenotype which have an aggressive behavior and the lowest response to tamoxifen therapy.