Progesterone receptors in routinely paraffin-embedded primary breast carcinomas and lymph node metastases

Systematic review on hormone receptor testing in breast cancer

Assessment of hormone receptors (estrogen and progesterone) helps to direct therapy for women with breast cancer. Immunohistochemistry is most commonly used to assess hormone receptor status and it is essential that these tests are performed accurately and reliably within and across laboratories. The overall purpose of this guideline is to improve the quality and accuracy of hormone receptor testing and its utility as a prognostic and predictive marker for invasive and in situ breast cancer. Medline, EMBASE, the Cochrane Database of Systematic Reviews, and abstracts from the San Antonio Breast Cancer Symposium were searched. An environmental scan of the internet and of international guideline developers and key organizations was performed. Preanalytic elements such as the collection, fixation, and storage of samples, and analytic elements such as selection of antibodies and scoring methods that seem to offer the best results for immunohistochemical assessment of hormone receptors are presented. Proficiency testing or quality assurance of immunohistochemistry is described.

Cancer care Ontario guideline recommendations for hormone receptor testing in breast cancer

Hormone receptor testing (oestrogen and progesterone) in breast cancer at the time of primary diagnosis is used to guide treatment decisions. Accurate and standardised testing methods are critical to ensure the proper classification of the patient's hormone receptor status. Recommendations were developed to improve the quality and accuracy of hormone receptor testing based on a systematic review conducted jointly by the American Society of Clinical Oncology/College of American Pathologists and Cancer Care Ontario's Program in Evidence-Based Care. Evidence-based recommendations were formulated to set standards for optimising immunohistochemistry in assessing hormone receptor status, as well as assuring quality and proficiency between and within laboratories. A formal external review was conducted to validate the relevance of these recommendations. It is anticipated that widespread adoption of these guidelines will further improve the accuracy of hormone receptor testing in Canada.

Progesterone receptor by immunohistochemistry and clinical outcome in breast cancer: a validation study

Progesterone receptor is a surrogate marker of estrogen receptor activity in breast cancer and its utility in helping predict clinical outcome has been established using biochemical assays. However, most laboratories worldwide have switched to immunohistochemistry to assess progesterone receptor, but unfortunately no validated immunohistochemical assay exists for progesterone receptor. The purpose of this study was to develop and validate an immunohistochemical assay for progesterone receptor in breast cancer. The assay was based on monoclonal antibody 1294 (DakoCytomation) and slides were scored microscopically using the 'Allred score' on a scale of 0-8. The assay was compared to ligand-binding assay in 1235 breast cancers, and a subset (n=362) that received only hormonal therapy was used to define a cutoff for progesterone receptor-positive. Clinical utility was validated in an independent set of samples (n=423) from a clinical trial randomizing premenopausal breast cancer patients to tamoxifen+oophorectomy vs observation following surgery. A cutoff of >2 (corresponding to >1% positive cells) dichotomized patients with significantly better or worse clinical outcome (P=0.0014). Progesterone receptor by immunohistochemistry provided significantly better results than progesterone receptor by ligand-binding assay in predicting clinical outcome. In the clinical trial, a positive result in univariate analyses was associated with significantly improved disease-free and overall survival both in untreated (hazard ratios/P=0.656/0.060 and 0.479/0.005, respectively) and hormonally treated patients (hazard ratios/P=0.529/0.017 and 0.451/0.007, respectively). Positive progesterone receptor remained significant for improved disease-free and overall survival (hazard ratios/P=0.666/0.038 and 0.549/0.007, respectively) in multivariate analyses including the standard variables of tumor size, nodal status, treatment, histological grade, and HER-2/neu status. Estrogen and progesterone receptors are codependent variables and progesterone receptor was a weaker predictor of response to endocrine therapy than estrogen receptor when both were included in multivariate analysis. This is the first comprehensive study assessing the clinical usefulness of progesterone receptor by immunohistochemistry in archival tissue in breast cancer. Progesterone receptor assessed by immunohistochemistry provides useful information about clinical outcome and it is better than progesterone receptor measured by ligand-binding assay.

Steroid Hormone Receptor Immunohistochemistry in Breast Cancer: Past, Present, and Future

This article reviews the development of steroid hormone receptor detection using the biochemical approach and the disadvantages inherent in these systems. The early history of methods for the in situ detection of receptors is related, culminating in the development of histologic immunoassays using monoclonal antibodies. Correlation of the latter with disease-free and overall survival and with clinical endocrine response are presented together with preliminary findings utilizing a new generation of antireceptor antibodies. Current problems with test scoring and interpretation are detailed with a section devoted to image analysis for assay quantification. Emphasis is placed on the fact that because so many different antibodies and tissue substrates have been employed in the past, these histologic receptor immunoassays cannot yet be considered to be fully validated. It is stressed that different laboratories must employ the same antibodies, substrates, detection systems and methods of scoring, and then correlate findings with measurable clinical end points. Only then can the assays be included in the brief list of approved breast cancer prognostic and predictive markers to eventually replace the routine biochemical methods of steroid receptor detection.

Absence of progesterone receptor associated with secondary breast cancer in postmenopausal women

The relationship between expression of receptors for oestrogen and progesterone (ER and PR) and disease progression in breast cancer was investigated by comparing immunocytochemical determinations of ER and PR in fine needle aspirates from primary and secondary breast tumours. Rates of receptor expression were significantly higher in primary than in secondary lesions: for ER 63.3% (n = 689) compared with 45.3% (n = 223), and for PR 53.7% (n = 443) compared with 33.1% (n = 121). The effect of menopausal status was examined by subdividing the patient cohort into those over or under the age of 50 years. In both instances, ER expression in secondary tumours was relatively low; however, only postmenopausal patients had significantly lower rates of PR expression in secondary tumours. Consistent with this, an increase in the ER+PR- profile in secondary tumours compared with primary cases from postmenopausal patients was seen, and in a multivariate analysis, a specific absence of PR expression in secondary tumours was revealed. Comparison of ER and PR expression in simultaneously sampled primary tumours and lymph node metastases from the same patient showed that receptor expression was stable with progression to a metastatic site as results were concordant for ER in 92% (n = 88) and PR in 93.8% of cases (n = 65). These results suggest that absence of PR expression in primary breast cancer is associated with disease progression and may be a marker of an aggressive tumour phenotype.

Immunocytochemical versus biochemical receptor determination in normal and tumorous tissues of the female reproductive tract and the breast

The development of highly specific and sensitive monoclonal antibodies directed against human estrogen (ER) and progesterone receptors (PR) provides a new approach in precise histochemical receptor location independent of hormone binding. Over the years receptor determination was the domain of the radioligand-binding assay, in which receptors are measured by tritiated ligand and unbound ligand is removed by the dextran-coated charcoal (DCC) procedure. Presented here are the results and experiences obtained by the classic DCC and the immunocytochemical method in the different normal and tumorous tissues of the female reproductive tract and the breast. The results of both methods were compared, and overall concordance of the results was found to vary considerably among the different types of tissue analyzed. Best agreement (86%) was found for PR determination in breast cancer, and the lowest rate of concordance for ER determination in fibrocystic disease of the breast. Special attention was directed toward the heterogeneity of receptor distribution in the specimens examined. In all tissues investigated, ER and PR were located in the nuclei of cells in both paraffin and frozen sections. Staining intensity varied among different cell types and from cell to cell for a single cell type, as well as in tumorous and normal tissues. In breast cancer, randomly scattered single cell receptor positivity was distinguished from focal/clonal positivity. Paraffin-embedded lymph node metastases showed significantly weaker staining as compared with their respective primary tumors. In the normal ovary, the corpus luteum and the stromal layer of the outer cortex were revealed as highly receptive elements for progestins, whereas ER was barely demonstrable in the normal ovary. Benign serous and mucinous ovarian tumors showed opposite ER and PR distribution among the stromal and epithelial components. Of special interest were the highly significant changes in ER and PR content in the stromal and glandular cells of the different layers of the normal endometrium throughout the menstrual cycle.