Semiquantitative oestrogen receptor assay in formalin-fixed paraffin sections of human breast cancer tissue using monoclonal antibodies

Canine mammary tumors: a review and consensus of standard guidelines on epithelial and myoepithelial phenotype markers, HER2, and hormone receptor assessment using immunohistochemistry

Although there have been several studies on the use of immunohistochemical biomarkers of canine mammary tumors (CMTs), the results are difficult to compare. This article provides guidelines on the most useful immunohistochemical markers to standardize their use and understand how outcomes are measured, thus ensuring reproducibility of results. We have reviewed the biomarkers of canine mammary epithelial and myoepithelial cells and identified those biomarkers that are most useful and those biomarkers for invasion and lymph node micrometastatic disease. A 10% threshold for positive reaction for most of these markers is recommended. Guidelines on immunolabeling for HER2, estrogen receptors (ERs), and progesterone receptors (PRs) are provided along with the specific recommendations for interpretation of the results for each of these biomarkers in CMTs. Only 3+ HER2-positive tumors should be considered positive, as found in human breast cancer. The lack of any known response to adjuvant endocrine therapy of ER- and PR-positive CMTs prevents the use of the biological positive/negative threshold used in human breast cancer. Immunohistochemistry results of ER and PR in CMTs should be reported as the sum of the percentage of positive cells and the intensity of immunolabeling (Allred score). Incorporation of these recommendations in future studies, either prospective or retrospective, will provide a mechanism for the direct comparison of studies and will help to determine whether these biomarkers have prognostic significance. Finally, these biomarkers may ascertain the most appropriate treatment(s) for canine malignant mammary neoplasms.

The estrogen receptor pathway in rhabdomyosarcoma: a role for estrogen receptor-beta in proliferation and response to the antiestrogen 4'OH-tamoxifen

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. Highly malignant, RMS frequently fails to respond to conventional aggressive multimodal radiation, surgery, and chemotherapy treatment protocols that also cause significant sequelae in the growing child. Other tumors of mesenchymal origin, such as locally aggressive fibromatoses and desmoid tumors, have been successfully treated with a selective estrogen receptor (ER) modulator, tamoxifen. In an effort to identify new targets for RMS therapy, our group investigated the previously uncharacterized ER pathway in RMS cell culture and primary tumors. We detected ER isoform beta (ER beta), but not isoform alpha, RNA, and protein in five RMS cell lines. Immunohistochemical staining of primary RMS tumor sections confirmed high levels of ER beta but not ER alpha protein. RMS cell growth was dramatically inhibited in steroid-free conditions, and this growth inhibition was rescued with 17-beta-estradiol (E2) supplementation. Exposure of RMS cells to 4'OH-tamoxifen (4OHT) decreased cell viability and inhibited colony formation as detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and colony-forming assays. 4OHT also induced apoptotic signaling in RMS cells as detected by cleavage of caspase-3 and poly(ADP)ribose polymerase. This effect increased 3- to 8-fold in steroid-deprived conditions but was rescued by supplementation with E2. Immunofluorescence studies detected a change in the subcellular localization of ER beta in response to 4OHT. Together, these data suggest an active ER beta-mediated signal transduction pathway in RMS. The ability of 4OHT to induce apoptotic signaling and disrupt estradiol-mediated proliferation provides a rationale to explore a role for selective ER modulators in the treatment of RMS.

UDP-glucuronosyltransferase and sulfotransferase polymorphisms, sex hormone concentrations, and tumor receptor status in breast cancer patients

INTRODUCTION

UDP-glucuronosyltransferase (UGT) and sulfotransferase (SULT) enzymes are involved in removing sex hormones from circulation. Polymorphic variation in five UGT and SULT genes - UGT1A1 ((TA)6/(TA)7), UGT2B4 (Asp458Glu), UGT2B7 (His268Tyr), UGT2B15 (Asp85Tyr), and SULT1A1 (Arg213His)--may be associated with circulating sex hormone concentrations, or the risk of an estrogen receptor-negative (ER-) or progesterone receptor-negative (PR-) tumor.

METHODS

Logistic regression analysis was used to estimate the odds ratios of an ER- or PR- tumor associated with polymorphisms in the genes listed above for 163 breast cancer patients from a population-based cohort study of women in western Washington. Adjusted geometric mean estradiol, estrone, and testosterone concentrations were calculated within each UGT and SULT genotype for a subpopulation of postmenopausal breast cancer patients not on hormone therapy 2-3 years after diagnosis (n = 89).

RESULTS

The variant allele of UGT1A1 was associated with reduced risk of an ER- tumor (P for trend = 0.03), and variants of UGT2B15 and SULT1A1 were associated with non-statistically significant risk reductions. There was some indication that plasma estradiol and testosterone concentrations varied by UGT2B15 and SULT1A1 genotypes; women with the UGT2B15 Asp/Tyr and Tyr/Tyr genotypes had higher concentrations of estradiol than women with the Asp/Asp genotype (P = 0.004). Compared with women with the SULT1A1 Arg/Arg and Arg/His genotypes, women with the His/His genotype had elevated concentrations of testosterone (P = 0.003).

CONCLUSIONS

The risk of ER- breast cancer tumors may vary by UGT or SULT genotype. Further, plasma estradiol and testosterone concentrations in breast cancer patients may differ depending on some UGT and SULT genotypes.

Estrogen receptor expression profile of disseminated epithelial tumor cells in bone marrow of breast cancer patients

The estrogen receptor (ER) status in primary breast cancer represents an important prognostic factor and has a profound impact on therapeutic decisions. However, ER expression profile on disseminated breast cancer cells is largely unknown, although these cells are one of the main target structures in adjuvant therapy after local curative resection (R0) achieved in most breast cancer patients. Thus, the present pilot study was designed to evaluate the ER expression profile on disseminated epithelial cells in bone marrow, one of the preferential organs for manifestation of distant metastases in breast cancer. Using the alkaline phosphatase anti-alkaline phosphatase-immunogold double staining procedure, in a panel of 17 breast cancer patients, epithelial cells (mab CK2) detected in bone marrow were analyzed for ER expression (mab 1D5) and compared with ER expression in the corresponding primary tumors. Whereas eleven of the 17 patients (64.7%) were ER-positive in primary carcinomas, only two patients (11.8%) revealed ER-positive epithelial cells in bone marrow. In addition, one of these two patients demonstrated a heterogeneous ER expression pattern, with both ER-positive and ER-negative epithelial cells in bone marrow. Although in both of these cases the ER-positive epithelial cells in bone marrow derived from ER-positive primary tumors, in this small patient cohort none of the prognostic relevant clinical and pathological factors tested, i.e., TNM-classification, grading, and ER status in primary breast cancer, correlated with the ER status in bone marrow. The striking discrepancy between ER expression in primary breast cancers and the corresponding disseminated epithelial cells in bone marrow suggests either the selective dissemination of ER-negative tumor cells into the bone marrow or a negative impact of the bone marrow microenvironment on epithelial ER expression. This phenomenon might influence therapeutic effects of antihormonal treatment.

Organochlorine exposures influence on breast cancer risk and survival according to estrogen receptor status: a Danish cohort-nested case-control study

BACKGROUND

The relationship between breast cancer and organochlorine exposure is controversial and complex. As estrogen receptor positive and negative breast cancer may represent different entities of the disease, this study was undertaken to evaluate organochlorines influence on breast cancer risk and survival according to receptor status.

METHODS

The background material stems from the Copenhagen City Heart Study (Denmark 1976-78). The breast cancer risk was investigated in a cohort nested case-control design including 161 cases and twice as many breast cancer free controls. The cases served as a cohort in the survival analysis. Serum organochlorine concentrations were determined by gaschromotography.

RESULTS

The observed increased breast cancer risk associated with exposure to dieldrin derived from women who developed an estrogen receptor negative (ERN) tumor (Odds ratio [OR] I vs. IV quartile, 7.6, 95% confidence interval [95% CI] 1.4-46.1, p-value for linear trend 0.01). Tumors in women with the highest dieldrin serum level were larger and more often spread at the time of diagnosis than ERP tumors. The risk of dying was for the remaining evaluated compounds higher among patients with ERP breast cancer when compared to those with ERN. In the highest quartile of polychlorinated biphenyls (SigmaPCB) it was more than 2-fold increased (Relative risk [RR] I vs. IV quartile, 2.5, 95% CI 1.1-5.7), but no dose-response relation was apparent.

CONCLUSION

The results do not suggest that exposure to potential estrogenic organochlorines leads to development of an ERP breast cancer. A possible adverse effect on prognosis of hormone-responsive breast cancers needs to be clarified.

Highly sensitive immunohistological study for detection of estrogen receptor in human breast cancer

BACKGROUND

Immunohistological methods for the detection of estrogen receptor in human breast cancer using formalin-fixed, paraffin-embedded tissue not only have the advantages of being cheaper and requiring less tissue but also have several theoretical advantages. For example, such methods enable direct histological visualization of the assessed tissue and thereby reduce sampling error. Traditional immunohistological methods (traditional LSAB), however, show false-negative reactions more often than the enzyme-binding immunoassay method (EIA).

METHODS

After determining 25 estrogen receptor-positive cases and 50 estrogen receptor-negative cases by EIA, we analyzed these same cases using a traditional LSAB method and a new highly sensitive immunohistological method for assaying formalin-fixed, paraffin-embedded tissue.

RESULTS

Using this new method, we detected 10 instances of positive estrogen receptors among the 50 EIA receptor-negative cases. The 25 EIA-positive cases were positive for estrogen receptor antigen except 1case using the new method.

CONCLUSIONS

This new method not only has the advantage of use in paraffin-embedded tissue but also is more sensitive than the EIA. We recommend this new method as a choice to decrease false-negatives.

The prognostic value of p53 and c-erb B-2 immunostaining is overrated for patients with lymph node negative breast carcinoma: a multivariate analysis of prognostic factors in 613 patients with a follow-up of 14-30 years

BACKGROUND

Approximately 30% of breast carcinoma patients with negative lymph nodes die of their disease. Biologic markers such p53 protein and c-erb B-2 have been related to tumor progression, but their prognostic value remains controversial.

METHODS

Two large series of a total of 613 lymph node negative breast carcinoma patients from a single institution were analyzed with respect to tumor size, histologic grade, and immunohistochemical staining for p53, c-erb B-2, estrogen receptor (ER), and progesterone receptor (PgR). Interobserver variation in histologic grading was evaluated by Kappa statistics. The two series had different treatment modalities: 228 patients (SACGS group) were treated surgically with mastectomy and given 1 perioperative chemotherapy course, and 385 patients (HOST group) were treated with mastectomy and ovarian radiation and further randomized to receive postoperative treatment with radiotherapy or no adjuvant treatment. The follow-up ranged from 14-30 years.

RESULTS

Immunoreactivities for p53, c-erb B-2, ER, and PgR did not differ significantly in the two series. p53 immunostaining was present in 187 of 613 tumors (29%), and c-erb B-2 immunoreactivity was present in 58 of the tumors (10%). Three hundred forty-eight tumors (57%) were positive for ER. Kappa statistics value of interobserver variation in the histologic grading of ductal carcinomas was 0.69, which is considered to be a substantial degree of agreement. No significant differences in survival were found when comparing p53, c-erb B-2, ER, and PgR positive and negative cases. However, both recurrence free survival rates and overall survival rates after 10 years were significantly better in the T1N0M0 group compared with the T2N0M0 group (81% vs. 67% [P < 0.0001] and 85% vs. 70% [P < 0.0001]). Ten-year recurrence free survival rates for patients with histologic Grade 1 versus Grades 2-3 (according to Elston and Ellis' modification of the Bloom and Richardson method) tumors were 90% and 70%, respectively (P < 0. 0001), and overall survival rates for the same groups were 94% and 81%, respectively (P=0.0002). After 30 years of follow-up, the overall survival rate for patients with tumors of histologic Grade 1 versus Grades 2-3 were 87% and 68%, respectively, and were 78% and 66%, respectively, for patients with tumors </= 2 mm versus those with tumors > 20-50 mm. Approximately 35% of the patients with tumors of histologic Grades 2-3 and measuring > 20 mm were dead after 10 years of follow-up, contrary to 6% of the patients with tumors of histologic Grade 1 measuring </= 20 mm. A significantly more favorable prognosis also was observed in patients in the HOST group treated with adjuvant radiotherapy.

CONCLUSIONS

Histologic grade and tumor size were found to be major prognostic factors for patients after 30 years of follow-up. c-erb B-2 and p53 immunostaining does not appear have any independent prognostic value. Adjuvant radiotherapy may be of value in the treatment of patients with localized tumors.

Retrieval of estradiol receptor in paraffin sections of resting porcine uteri by microwave treatment. Immunostaining patterns obtained with different primary antibodies

The unmasking of estradiol receptor in paraffin sections of Bouin's-fixed uterine tissue from ovariectomized gilts was attained with microwave treatment. Immunocytochemistry of the receptor was performed using a polyclonal or five monoclonal antibodies, two of which are commercially available, reacting with different domains of the protein and an amplified-peroxidase system for detection. With five of the antibodies, a predominance of nuclear staining was observed in cells of endometrial glands, while one monoclonal antibody (13H2), reacting with the receptor's domain E, showed a preference for the cytoplasmic receptor. In stroma, all antibodies detected more receptor in nuclei than in cytoplasm. In epithelium, the commercially available antibody H222, our monoclonals 13H2 and HT65, and the polyclonal antibody 402 demonstrated more receptor in cytoplasmic than in nuclear areas. In myometrium, the nuclei from longitudinal and ring muscles were definitely stained with the antibodies. We conclude that the accessibilities of the antibody epitopes of the receptor differ according to the functional uterine cell type.

Oestrogen receptor analysis of paraffin sections and cytosol samples of primary breast cancer in relation to outcome after adjuvant tamoxifen treatment. The South Sweden Breast Cancer Group

The aim of the present study was to compare oestrogen receptor (ER) analysis results obtained in cytosols of frozen breast cancer tissue (using biochemical assay) with those obtained in paraffin-embedded tissue (using immunoperoxidase staining with monoclonal antibodies (DAKO-ER, 1D5), and an ER positivity cut-off level of >10% stained nuclei). In 86% (84/98) of the samples the same ER status (28 negative and 56 positive) was obtained with both procedures. In eight cases, the paraffin section was ER positive but the corresponding cytosol sample ER negative, whereas six cases showed the opposite pattern. The ER positive subgroup manifested better outcome after adjuvant treatment than the ER negative subgroup (p = 0.003 (cytosol), and p = 0.004 (paraffin)). As compared with the percentage of stained nuclei, staining intensity yielded no additional information. Although the results of ER analysis of paraffin-embedded material seem promising, it is too early to prefer it to frozen tissue, though this would be useful when no frozen tissue is available.

A new immunohistochemical antibody for the assessment of estrogen receptor status on routine formalin-fixed tissue samples

We describe a method for the immunocytochemical assessment of estrogen receptor (ER) status on routinely processed, formalin-fixed tissue using a recently developed commercially available monoclonal antibody (Dako 1D5) with a microwave antigen retrieval technique. A series of 90 cases of human breast carcinoma was analyzed and the staining was assessed using a semiquantitative microscopic scoring method and by assessment of the percentage of nuclei showing positive staining. The results were compared with assessment using another commercially available antibody (Abbott H222) and with clinical response to tamoxifen therapy. Direct comparison of the paired sets of H scores and the percentage of positively stained nuclei using the two different techniques showed a significant correlation. By assigning an arbitrary cut-off for positivity of H score = 50, assessment of ER status using DAKO 1D5 antibody was found to correlate with response to tamoxifen therapy with a sensitivity of 90% and a specificity of 51%, similar to values in previous studies using other methods. We conclude that assessment of ER status using this new antibody and technique gives accurate results on routinely processed, formalin-fixed tissue and may be used as an alternative to other methods.

Wet autoclave pretreatment for immunohistochemical demonstration of oestrogen receptors in routinely processed breast carcinoma tissue

The immunohistochemical demonstration of oestrogen receptor (OR) was performed on 32 randomly selected and routinely processed breast carcinomas after wet autoclave pretreatment of sections. The autoclave method was compared to the OR status found on frozen sections as well as to alternative pretreatment methods such as enzymatic predigestion and microwave irradiation. Using four different monoclonal antibody clones (H222, LH1, CC4-5, 1D5.26), the OR status was evaluated for each of the various pretreatment methods applied. All cases with a high OR content on frozen sections (n = 11) also showed a high OR status on wet autoclave-pretreated paraffin tissues using antibody clones 1D5.26 and CC4-5; in cases with low OR content on frozen sections, no false-negative cases were recorded using only the antibody 1D5.26 neither after wet autoclave nor microwave pretreatment. In addition, with this antibody, OR was detectable after autoclave pretreatment in two cases which were considered to be OR-negative even on frozen sections. When the primary antibody was omitted, no false-positive cases were observed after wet autoclave pretreatment. Thus, in our hands, wet autoclave pretreatment, in combination with the antibody 1D5.26, offers a highly sensitive method for the immunohistochemical demonstration of OR in routinely formalin-fixed, paraffin-embedded sections of breast carcinomas.

The estrogen receptor expression in the male rabbit urethra and prostate following castration

The influence of castration on estrogen receptor (ER) expression in the male rabbit prostate and urethra, was investigated immunohistochemically and biochemically in 18 mature male, rabbits 14 days after bilateral orchiectomy, and in 15 controls. Immunohistochemical scores of ER were increased significantly in the prostatic stroma and the urethral submucosa (p < 0.05 Mann-Whitney), while the increase in the urothelium was not significant. Biochemically, the ER content was 87.4 +/- 42.6 f mol/mg protein in the normal prostate, and 190.0 +/- 28.0 f mol/mg protein following castration. The corresponding values for the posterior urethra were 228.3 +/- 43.2 f mol/mg protein and 354.9 +/- 60.1 f mol/mg protein. In both cases the increase was not significant. We conclude, that ERs in the prostate and the urethra of the male rabbit can be modified by hormonal manipulation. ERs may therefore be functionally active and not rudimentary.

Estrogen receptor assay in polymorphous low-grade adenocarcinoma and adenoid cystic carcinoma of salivary gland origin. An immunohistochemical study

An apparent relationship between breast cancer and salivary gland cancer has been observed, and there is one report in the literature that describes estrogen receptors in normal salivary gland and salivary gland cancers. With the use of a monoclonal antibody against estrogen receptor protein and the avidin-biotin immunoperoxidase procedure, we were unable to demonstrate estrogen receptors in formalin-fixed paraffin-embedded sections of either polymorphous low-grade adenocarcinoma or adenoid cystic carcinoma of salivary gland origin.

Immunocytochemical localization of oestrogen and progesterone receptors in primary adenocarcinoma of the cervix

Archival material from 47 primary invasive adenocarcinomas of the uterine cervix was examined using an immunocytochemical technique for detection of oestrogen receptor and progesterone receptor in paraffin-wax embedded tissues. Immunostaining for oestrogen receptor was noted within tumour cells in 12 cervical adenocarcinomas while 13 tumours contained progesterone receptor. Eleven cervical adenocarcinomas expressed both oestrogen and progesterone receptor simultaneously. There was no association between steroid receptor status and major histological subtype, grade of tumour, clinical stage or age of patient at presentation. However, oestrogen receptor immunoreactivity was associated with disease-free survival. This preliminary study raises the possibility that, as in breast carcinoma, steroid receptor status may be a useful prognostic factor in adenocarcinoma of the cervix.

Determination of Ki67 growth fraction and oestrogen receptors in screen-detected breast cancer using cytological preparations

Oestrogen receptor (ER) status of 77 cases of screen-detected breast cancer has been determined using cytological preparations. In 48% ER status was positive, which was the same proportion as that formed in a control group of age-matched patients with symptomatic breast carcinoma. Since the screen-detected group contained more low grade tumours, the percentage of ER-positive cases would be expected to be higher. The reasons for the discrepancy are discussed. Ki67 score has been determined for 41 cases of screen-detected cancer. Ki67 score showed a positive correlation with histological tumour grade and a negative correlation with ER status. However, there was no correlation with tumour size or lymph node status. The Ki67 scores in the screen-detected cancers were essentially similar to those found in an age-matched symptomatic group, but the very low scores were only found in the screened group.

Methodology of immunohistological detection of oestrogen receptor in human breast carcinoma in formalin-fixed, paraffin-embedded tissue: a comparison with frozen section methodology

We describe a method of immunohistochemically assessing estrogen receptor status on routinely processed formalin-fixed tissue, using a commercially available monoclonal antibody (Abbott H222), with pronase predigestion of tissue sections and overnight antibody incubation. The staining was assessed using the H score system. A series of 94 cases of breast cancer were analysed and the results were compared with assessment by oestrogen receptor immunocytochemical assay performed on frozen section. Direct comparison of the paired sets of H scores obtained with frozen tissue and formalin-fixed tissue showed a highly significant correlation of 0.8 (P < 0.001) between the two methods of oestrogen receptor assessment. Chi-squared analysis using H score cut off points of 50 and 100 also showed a similar significant association (P < 0.001). We conclude that this oestrogen receptor method, applicable to formalin-fixed, paraffin-embedded tissue, gives accurate results on routinely fixed tissue and could be used as an alternative to other methods.

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

Described here is an immunohistochemical technique using the commercially available monoclonal progesterone receptor (PR) antibody KD 68 in routinely fixed and paraffin-embedded breast carcinomas and lymph node metastases. The authors' technique is compared with several incubation variations. The method applying the primary antibody in a dilution of 1:10 overnight followed by a biotinylated second antibody showed the best results when Triton X-100 was added to the buffer. Using this method, comparison with the results on frozen sections of 34 breast carcinomas yielded a significant concordance of 94%. Correlation between the results on paraffin sections and those obtained by the standard dextran-coated charcoal cytosol assay was 80%. The value of the method for predicting endocrine therapy response was shown in 20 patients. Thus the reliability of the method has been demonstrated and was applied on 151 lymph node metastases and the corresponding primary breast carcinomas from 50 patients. Generally PR content in the metastases was lower than in the primary tumors (p < 0.001). This finding indicates that evaluation of PR in lymph node metastases should be included in the decision for endocrine therapy of breast cancer.

Oestrogen receptor protein and mRNA in adenocarcinoma of the uterine cervix

We have investigated the oestrogen receptor (ER) status of 20 cervical adenocarcinomas by immunocytochemistry for ER protein and non-isotopic in situ hybridisation for ER mRNA. Both methods, which are applicable to paraffin sections, were developed and validated in breast carcinomas with known ER content. Six cervical adenocarcinomas contained immunocytochemically demonstrable ER protein; all contained ER mRNA, but staining was less intense in poorly differentiated areas of four tumours. This disparity between protein and mRNA detection needs further investigation as does the possibility that oestrogens may play a role in the pathogenesis of cervical adenocarcinoma.

Immunocytochemical localization of estrogen and progesterone receptors in imprint preparations of breast carcinomas

The role of mammography as an effective means of early detection of breast cancer is well established. Needle localization of occult tumors under mammographic guidance has become the principle method of sampling impalpable breast lesions. As a result, the number of clinically inapparent breast carcinomas sampled has increased rapidly. Under these circumstances, as a result of the size and the nature of these "early carcinomas," it may not be possible to assess the hormone receptor expression of these tumors by conventional biochemical assay and/or immunocytochemical analysis. To determine the usefulness of imprint preparation for detecting hormone receptors, 214 examples of primary, recurrent, and metastatic breast cancers were studied. Immunostaining of imprint preparations with monoclonal antibodies against the estrogen (H222SPy) and progesterone receptors (KD68) showed a high degree of concordance with immunocytochemical assay and biochemical analysis done on frozen tissue of the same tumors. This technique can be done easily and is well suited for tumors that are too small and/or ill defined to permit separate sampling for hormone receptor analysis.

Aggressive stage I grade 1 endometrial carcinoma

BACKGROUND

Patients with Stage I Grade 1 endometrial carcinoma have an excellent prognosis and a 10-year survival rate of more than 90%. In every clinical series, however, a few patients in this group have recurrence and die of their disease.

METHODS

The authors reviewed 80 patients with Stage I Grade 1 endometrial carcinoma treated at their institution from 1955-1980. Eight patients died of recurrent disease within 4 years of diagnosis. The authors studied multiple clinical and histopathologic features, estrogen receptor (ER) and progesterone receptor (PR) status, DNA flow cytometric characteristics, and the expression of c-myb, H-ras, and neu oncogenes. Results were compared with those for a control group of 11 patients who survived more than 10 years free of disease.

RESULTS

The authors identified the following four statistically significant adverse prognostic factors: myometrial invasion, vascular invasion, 8 or more mitoses per 10 high-power fields, and an absence of PR. Residual tumor, aneuploidy, and high proliferative activity were associated with a more aggressive behavior, although the relationship did not reach statistical significance.

CONCLUSIONS

All patients who died of disease within 4 years had tumors with two or more of the significant adverse prognostic factors.

Determination of estrogen receptors in paraffin-embedded tissue. Techniques and the value in breast cancer treatment

Estrogen receptor (ER) analysis in breast cancer has been used in three clinical situations: to select patients with advanced breast cancer for hormonal therapy, as a prognostic parameter, and for selection of women with early breast cancer to adjuvant hormonal treatment. ER has traditionally been measured using labelled hormone in binding assays--often in dextran-coated charcoal assays (DCC). Monoclonal antibodies to ER has permitted development of a solid phase enzyme immunoassay (ER-EIA) used for quantitative determination of ER in tissue homogenates, and have also been used for determination of ER using an immunohistochemical assay in frozen sections (ER-ICA) or in formalin-fixed, paraffin-embedded tissue (ER-PAR). A large number of studies has compared ER-EIA with ER-DCC assays. There is a good linear correlation between the two types of assay but ER-EIA measure more ER and classify a larger fraction of tumors ER-positive than conventional ER assays. Lack of clinical data makes the significance of this uncertain. Numerous studies have reported on the correlation between ER-ICA and ER-DCC or ER-EIA. There is a good correlation among the assays on classification of ER status with a median 86% concordance, but a somewhat poorer correlation between semiquantified ER of immunohistochemical assays and ER determined by the quantitative methods (median coefficient of correlation 0.67). There is a large variation in the cut-off level for definition of ER-positive in immunohistochemical assays emphasizing the need for quality control studies. The major problem involved in ER analysis in paraffin-embedded tissue is a considerable loss of immunoreactivity compared to sections from frozen tissue. This can partly be overcome by modifications of the immunohistochemical technique using enzyme pretreatment and other amplification systems, but the sensitivity of ER-PAR remains lower than ER-ICA despite these modifications, and the ER status is less reliably determined in tumors with low ER contents (< 100 fmol). The prognostic value of ER-PAR was evaluated with a multivariate analysis. The endpoint was disease-free interval in systemically untreated patients with early breast cancer, and the variables used were: ER-DCC, ER-PAR, age, tumor size, tumor grade, and nodal status. A total of 133 patients from the Danish Breast Cancer Cooperative Group's (DBCG) 77c protocols had a complete set of variables. The analysis showed that only nodal status, ER-DCC, and tumor grade were significant and independent prognostic variables. An overview of larger multivariate studies on mainly node-negative patients failed to show independent prognostic significance of ER-DCC.(ABSTRACT TRUNCATED AT 400 WORDS)

Immunocytochemical determination of the estrogen-regulated proteins Mr 24,000, Mr 52,000 and DF3 breast cancer associated antigen: clinical value in advanced breast cancer and correlation with estrogen receptor

The Mr 24,000 and Mr 52,000 estrogen-regulated cytosol proteins, and the breast cancer-associated antigen DF3 have been studied in an immunocytochemical assay. Primary tumor specimens from 119 patients with advanced breast cancer who received endocrine therapy have been studied. Monoclonal antibodies were used for the detection of the proteins in formalin-fixed paraffin-embedded blocks. No correlation between Mr 52,000-positive specimens and the presence of estrogen receptor (ER) could be established (p = 0.87, chi-square test) whereas a statistically significant association between Mr 24,000 (p = 0.0002), DF3 antigen (p = 0.044) and ER was demonstrated. No intercorrelation was found between Mr 24,000 and Mr 52,000 or DF3 (p = 0.63, 0.98 and 0.12 respectively). Clinical response was evaluated for immunocytochemical findings, Mr 24,000 (p = 0.37), Mr 52,000 (p = 0.61) and DF3 (p = 0.68) showed no association whereas ER was statistically correlated (p = 0.00005). Neither overall survival nor disease-free survival correlated to Mr 24,000 (p = 0.18 and 0.75 respectively, logrank test), Mr 52,000 (p = 0.095 and 0.38), or DF3 (p = 0.22 and 0.13) staining, whereas ER-positive tumors did (p = 0.00005). Discrimination between ER-positive responders and ER-positive non-responders was not possible using either Mr 52,000, Mr 24,000 or DF3 staining. Based on our findings we conclude that immunocytochemical staining for Mr 52,000, Mr 24,000 or DF3 cannot be used as a marker to predict response to endocrine therapy in patients with advanced or recurrent breast cancer.

An immunohistochemical evaluation of progesterone receptor in frozen sections, paraffin sections, and cytologic imprints of breast carcinomas

Two monoclonal antibodies to progesterone receptor (PR), JZB39 and KD68, were used for the immunocytochemical visualization of PR in different kinds of breast cancer specimens including (1) cryostat sections of tumors frozen at -80 degrees C; (2) paraffin sections of tumors fixed in formalin or in Bouin's fixative for varying periods of time at room temperature or at 4 degrees C; and (3) imprints and cryostat sections prepared from the tissue used for frozen section diagnosis and stored at -80 degrees C after fixation in Zamboni's solution. Sections of conventionally frozen specimens as well as imprints and cryostat sections stored for varying periods of time were stained with the peroxidase-antiperoxidase technique, whereas the avidin-biotin technique was used for paraffin sections. In all types of specimens the PR immunostaining was localized to the nuclei of carcinoma cells and displayed considerable heterogeneity both in intensity and in distribution of positive cells. Close correspondence was found between the different immunohistochemical techniques as well as between immunostaining and steroid-binding assays. PR staining was more frequently positive in well-differentiated than in moderately or poorly differentiated carcinomas, whereas no meaningful correlation was found between PR staining and extent of the disease. Similar results were obtained with the immunostaining of estrogen receptor in the same material using monoclonal antibodies H222 and D75P3 gamma. Thus, by choosing the technique that best suits the type of specimen available, it is possible to obtain valid information on the receptor status of any breast carcinoma, regardless of its size and clinical presentation.

Relation between estrogen receptor and malignancy of thyroid cancer

The relationship between the histological grade of dedifferentiation of thyroid cancer and estrogen receptors (ER) was examined immunohistochemically. Thyroid cancers were from postmenopausal females of almost the same mean age (69-73 years old) and within the same period of time (1974-1983). ER immunoreactivity located in the nucleus of the epithelium was found in all 6 well differentiated papillary cancers, and 5 of them (83.3%) showed ER-immunoreactive (ER-IR) cells amounting to 20 or more per visual field (x 100) under a light microscope. Of the 6 cases of poorly differentiated papillary cancer, 5 (83.3%) had 1-19 ER-IR cells per visual field. ER-IR cells were negative in 5 out of 6 cases (83.3%) of anaplastic cancers. Thus, the number of ER-IR cells tended to decrease with the degree of atypism of thyroid cancer (P less than 0.001).

Oestrogen receptor staining of paraffin-embedded breast carcinomas following short fixation in formalin: a comparison with cytosolic and frozen section receptor analyses

This paper describes an improved immunohistochemical method for demonstrating oestrogen receptor (OR) protein in paraffin-embedded sections of tissue fixed for 1.5 h in formalin. Thirty-two cases of infiltrating ductal breast carcinoma were stained with a monoclonal anti-OR antibody (H222), using a standard streptavidin-biotin method, following pretreatment with pronase. OR counts in paraffin sections were compared with those of frozen sections and with cytosolic values determined by a dextran-coated charcoal method. Twenty-seven of the carcinomas were OR-positive in paraffin sections. There was concordance between the paraffin section and the frozen section-determined receptor status in 30 cases (94 per cent) and a strong correlation was observed (r = 0.76; P less than 0.0001). Similarly, OR counts in paraffin sections correlated with cytosolic OR values (r = 0.60; P less than 0.001) and there was concordance in 97 per cent of cases. The percentage of positively-stained tumour cells in paraffin sections ranged from 0 to 94 per cent with staining intensities comparable to those seen in frozen sections. Staining of paraffin sections identified more OR-positive tumours than either frozen section staining or cytosolic assay. This study validates immunohistochemical OR analysis in formalin-fixed, paraffin-embedded breast carcinomas using a commercial anti-OR antibody.

The prognostic value of immunohistochemical estrogen receptor analysis in paraffin-embedded and frozen sections versus that of steroid-binding assays

Estrogen receptors (ER) were independently analyzed using dextran-coated charcoal assays (ER-DCC) and immunohistochemical assays in frozen (ER-ICA) and paraffin-embedded tissue (ER-PAR) from 130 human breast cancer specimens drawn from postmenopausal high-risk patients registered in the Danish Breast Cancer Cooperative Group. ER was best detected with the ER-DCC assay followed by the ER-ICA (relative sensitivity 87%) and the ER-PAR assays (relative sensitivity 71%). The semiquantified staining features of the immunohistochemical assays were statistically significantly correlated with each other and with ER-DCC. Analysis of disease-free interval (DFI) and overall survival (OS) showed that all assays allowed statistically significant discrimination between a high risk and a low risk group, although the sensitivity differences tended to be reflected as small differences in clinical discriminatory power. The patient groups were then stratified according to adjuvant treatment [radiotherapy (RT) versus radiotherapy and tamoxifen (RT + TAM)]. The survival advantage was tied primarily to the receptor status itself in the steroid-binding assays, but was linked to both the receptor status and the adjuvant treatment in the immunohistochemical assays. Thus, the relative risks in terms of DFI and OS were of the same relative magnitude in the RT and RT + TAM groups for ER-DCC assays using a cut-off level of 10 fmol/mg cytosol protein, while there were large differences in the relative risks between RT and RT + TAM groups for ER-ICA and ER-PAR assays. We conclude that an ER assay in fresh tissue should be given first priority, but if there is no fresh tissue, an ER assay in paraffin-embedded tissue offers a reasonably good alternative as a prognosticator and an equivalent alternative as a predictor of the response to endocrine treatment.

Immunohistochemical analysis of estrogen receptors in human gallbladder

Estrogen receptors (ER) in human gallbladders were examined immunohistochemically using a specific monoclonal antibody against human ER. ER immunoreactivity was positive in 6 (19.4%) of 31 cases of cholelithiasis, 6 (33.3%) of 18 cases of epithelial polyp, 14 (53.8%) of 26 cases of adenoma, and 26 (22.8%) of 114 cases of adenocarcinoma. ER immunoreactivity was located at the nucleus of the epithelium of both non-neoplastic and neoplastic tissues, although the number of ER-immunoreactive cells was small. There was no sex difference in the incidence of ER immunoreactivity. No significant difference in survival rates could be demonstrated between ER-positive and ER-negative carcinomas. Epithelial polyps, adenomas and carcinomas were divided into metaplastic type and non-metaplastic type based on the presence or absence of metaplastic changes for comparison of the incidence of ER immunoreactivity. The incidence of ER immunoreactivity in the metaplastic type was significantly higher than that in the non-metaplastic type. We conclude that ER are present in the gallbladder mucosa in various disease states and suggest that the presence of ER is related to metaplasia of the gallbladder mucosa.

Assessment of oestrogen receptor content of breast carcinoma by immunohistochemical techniques on fixed and frozen tissue and by biochemical ligand binding assay

The oestrogen receptor content of 61 breast carcinomas was assessed by biochemical ligand binding assay and three immunohistochemical techniques--a frozen section method (Abbott ER-ICA) and on paraffin wax sections after fixation by two methods. The two fixatives used were Carson's buffered formalin and methacarn, and a DNAse pretreatment of sections was used. Overall agreement for the immunohistochemical methods with the ligand binding technique were 95%, 85%, and 86% for the frozen, formalin, and methacarn methods, respectively. A semiquantitative staining score was performed and all three methods gave significant correlations of staining scores with biochemical ligand binding values. The frozen section method was best (r = 0.88) with the fixed tissue methods yielding poorer correlation coefficients. Several factors affected staining, including the nature of the fixative and variable activity of DNAse. It is concluded that immunohistochemical assessment of oestrogen receptor content on fixed tissue provides acceptable qualitative information but that standardisation of protocols for tissue processing will be necessary for optimal utility and especially for quantitative assessments.

Immunohistochemical study of androgen receptor in benign hyperplastic and cancerous human prostates

Androgen receptor was detected immunohistochemically in benign as well as malignant prostatic tissues by using a monoclonal rat anti-human androgen receptor antibody (AN 1-15). In both benign and malignant cells, the androgen receptor was exclusively localized in nuclei. In hyperplastic prostate, the androgen receptor was stained in the glandular and the stromal cells. In the gland, cells facing the lumen were stained more intensively than those adjacent to the basal membrane. In cancer tissue, receptor-positive and -negative cancer cells were intermingled. The percent of strongly positive cancer cells was correlated inversely with grade. Relapsed cells showed a low population of strongly positive cells irrespective of grade.

Immunohistochemical detection of estrogen receptors in paraffin sections from primary and metastatic breast cancer

With the availability of monoclonal antibodies against the estrogen receptor (ER) it is possible to demonstrate the presence of ER immunohistochemically. Some of the antibodies are claimed to be reactive in formalin fixed, paraffin embedded tissue. We have evaluated the reactivity of one of these antibodies, D75 and found an acceptable reaction in routinely formalin fixed, paraffin embedded tissue. The antibody was applied to both primary and secondary tumors from a group of patients with recurrent breast cancer. The metastatic lesions consisted of lymph node metastases, bone marrow metastases, and liver metastases. While 41% of the primary tumors were ER-positive, this was only the case with 35%, 20%, and 17% of the lymph node, bone marrow, and liver metastases, respectively. The discordance between the ER-status of the primary tumor and the distant metastasis was 41% in cases of bone marrow metastases, and 44% in liver metastases. In most cases the shift was from an ER-positive primary tumor to an ER-negative metastasis. The results support the hypothesis that ER-negative tumor cells are probably more aggressive with a larger metastatic potential than the higher differentiated, ER-positive tumor cells.

Oestrogen receptors in benign epithelial lesions and intraduct carcinomas of the breast: an immunohistological study

We examined 198 breast lesions, representing commonly encountered benign epithelial proliferative disorders, lobular carcinoma in situ and intraduct carcinoma, immunohistologically for oestrogen receptors (ER). A mixture of three ER monoclonal antibodies--H222, D75 and D547--was used on sections of routinely processed and paraffin-embedded tissue blocks. Over 65% of the benign and malignant lesions showed some evidence of ER expression and significant staining was recorded by two observers in 28-31% of fibroadenomas, 18-28% of ductal epithelial hyperplasias, 30-40% of sclerosing adenosis cases, 38-45% of papillomas, 60% of in situ lobular carcinomas and 42-45% of intraduct carcinomas. Apocrine metaplastic cells and myoepithelial cells showed absent or only weak staining. Amongst intraduct carcinomas, less than 20% of comedo carcinomas and over 50% of cribriform, papillary and solid variants showed significant ER staining.

Immunohistochemical estrogen receptor determination in paraffin-embedded tissue. Prediction of response to hormonal treatment in advanced breast cancer

A new immunohistochemical assay using a monoclonal estrogen receptor (ER) antibody (H222, Abbott Laboratories, North Chicago) for determination of ER in formalin-fixed paraffin-embedded tissue was applied to evaluate its clinical value in a group of 145 previously untreated patients with advanced breast cancer. Suitable histologic material was accessible in 137 of these patients, of whom 70% had ER-positive tumors. The ER-positive patients had a significantly longer median overall survival than ER-negative patients (67 versus 32 months, P much less than 0.001) and this was an effect of both a prolonged disease-free interval (27 versus 17 months, P less than 0.05) and a prolonged survival after recurrence (41 versus 15 months, P much less than 0.001). Response to endocrine therapy was obtained in 49% of the patients with ER-positive tumors and in 7% with ER-negative tumors (P much less than 0.001). Relationship between response and semiquantified individual staining features could not be established. It is concluded that ER analysis in formalin-fixed paraffin-embedded tissue offers clinically useful information for allocation of patients to endocrine therapy.

Oestrogen and progesterone receptors in human term placenta. Measurement by binding assays and immunological methods

Oestrogen and progesterone receptors have been implicated in human placental steroidogenesis, but studies developed to measure their concentration in this tissue at term yielded discrepant results. Potential inaccuracy of the binding assays, the technique used in previous studies, might influence the discrepancy. In the present study, oestrogen and progesterone receptors were investigated by two different approaches: binding assays with radiolabelled ligand and immunoassays with monoclonal antibodies against receptors. Binding assays included techniques to quantify free and occupied sites in both the cytosolic and nuclear fraction. Conditions intended to block or decrease potential causes of inaccuracy, such as proteolysis or thermal denaturation of the sites, were included in the assays. Cytosolic specific binding was measured by two different techniques, dextran-coated charcoal and hydroxylapatite, whereas nuclear sites were studied on salt-extracts and by exchange. Negative or moderately positive results were obtained for either oestrogen or progesterone receptors, but high levels of non-specific binding made the technique unreliable. Immunoassays included the use of two techniques, histochemistry and enzyme-linked-immunosorbent-assay (ELISA). Both frozen and paraffin (Bouin solution or buffered formalin as fixatives) sections were stained with monoclonal antibodies against the oestrogen receptor. Results were always negative in all cases. Levels of oestrogen and progesterone receptors were measured in either cytosol or nuclear extracts by ELISA. This technique was highly sensitive and reproducible. Results were negative for both the cytosolic and nuclear fractions of oestrogen receptors. For progesterone receptors, low positivity was obtained in either crude (3.2 +/- 0.4 fmol/mg protein, mean +/- s.e.) or ammonium sulphate precipitated cytosols (12.6 +/- 3.5 fmol/mg protein, mean +/- s.e.), whereas the values for nuclear extracts were 62.0 +/- 9.0 fmol/mg DNA (mean +/- s.e.). We conclude that: (1) oestrogen receptors could not be detected in human term placenta by the methods used in this study, and (2) low levels of progesterone receptors were detected in both cytosolic and nuclear extracts.

Estrogen receptor analyses in breast cancer: comparison of monoclonal immunohistochemical and biochemical methods

The estrogen receptor content in 100 female breast carcinomas was determined using the biochemical dextran-coated charcoal (DCC) method and the monoclonal estrogen receptor immunocytochemical assay (ER-ICA). Great care was taken to make procedures optimal in order to minimize preanalytical errors. A statistically highly significant correlation was found between the results of the two methods, which were qualitatively in accordance in 91 cases, while nine gave a negative ER-ICA but a weak positive DCC result. The quantitative correlations were also statistically significant but varied considerably in individual cases. Under optimal conditions, ER-ICA provides results similar to the DCC method, but it is still uncertain if it can stand alone in routine diagnosis.

Oestrogen receptor status of primary breast carcinomas and their metastases. Relation to pattern of spread and survival after recurrence

Immunohistochemical antibody techniques for detection of oestrogen receptors (ER) were applied to formalin fixed, paraffin embedded sections from 62 primary breast cancers, the metastases of their original regional lymph nodes (29 cases), bone marrow carcinosis (43 cases) and liver metastases (20 cases). Forty per cent of the primary tumours and 31% of the regional lymph node metastases were ER positive; in contrast, less than 20% of liver and bone marrow metastases were ER positive. The ER status of regional lymph node metastases was concordant with that of the primary tumour in 90% of the cases. The concordance rate was 75% for liver metastases and 58% for bone metastases. Patients with ER positive primary tumours had recurrence significantly more often in bone; ER negative tumours recurred more often in the liver. The survival after recurrence (SAR) was significantly related to the ER status of the primary tumour and to that of the regional lymph node metastases. In contrast, the SAR was not associated with the ER status of bone marrow carcinosis or liver metastases. Cox analyses showed that age and ER status of the primary tumour were the most important independent prognostic factors compared to other clinical, therapeutic, pathoanatomical and biochemical features. The study supports the hypothesis that tumour cell clones with different ER content are selected and adapted to grow in various anatomical sites. Moreover, the ER status of the primary tumour seems to be more important for the prognosis than the ER status of bone and liver metastases.

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.

Immunocytochemical determination of the estrogen-regulated protein Mr 24,000 in primary breast cancer and response to endocrine therapy

Monoclonal antibodies against an estrogen-regulated Mr 24,000 cytosol protein (p24) were used for immunocytochemical localization of p24 in formalin-fixed paraffin-embedded specimens from the primary tumor in 103 patients who received endocrine therapy for advanced breast cancer. Sixty-one per cent of the tumors showed p24-positive staining, and this correlated well with the presence of estrogen receptor (ER) (P = 0.00017, chi-square test). Response to endocrine therapy was obtained in 43% of the patients. A statistically significant association between p24 status and response could not be established, while response and ER status were highly correlated (P = 0.0000029, chi-square = 21.6). Discrimination between ER-positive responders and ER-positive non-responders was not possible using p24 staining.

Estrogen and progesterone receptors in gallbladder cancer

Cancerous tissues from 21 patients with primary gallbladder cancer were examined immuno-histochemically for the presence of receptors for estrogen (ER) and progesterone (PGR). ER and PGR, localized in the nucleus, were evident in 52.4 per cent and 0 per cent of the patients, respectively. Furthermore, ER and PGR were positive only in the cytoplasm of cancer cells in 28.6 per cent and 66.7 per cent, respectively. There was a higher tendency of moderately- and poorly-differentiated adenocarcinoma to have an ER-positive rate than well-differentiated adenocarcinoma. With respect to the relationship between ER and sex, ER-positive nuclei were observed in 8 of 14 women (57.1 per cent) and 3 of 7 men (42.9 per cent), but the difference between the two was not significant due to the small number of subjects. These result suggested that gallbladder cancers with ER in the nuclei may respond to antihormone therapy.

Human breast tumors: a comparison between the biochemical method of measuring estrogen and progesterone receptors and that of an immunohistochemical method

In a series of 94 human mammary carcinomas, the determination of total estrogen (ER) and progesterone (PR) receptors by a single saturating dose method (5 nM for ER, 10 nM for PR) using dextran-coated charcoal was compared to an immunohistochemical method utilizing ER monoclonal antibody (ER-ICA test). There was a good correlation expressed in positive terms between the ER-ICA test and the biochemical determination of ER (94% of concordance) with a statistical value of P less than 0.01 being found between the concentration of ER (biochemical) and the percentage of labeled cells (ER-ICA). The ER-ICA test complements the ER and PR (biochemical) and is particularly useful for ER determinations on small tumor specimens as no additional tissue other than that from the biopsy is required.

The cytochemical detection of oestrogen receptors in fine needle aspirates of breast cancer; correlation with biochemical assay and prediction of response to endocrine therapy

A total of 98 breast aspirates from patients with breast cancer have been fixed and stained for oestrogen receptors using the Abbott ERICA kit. In a preliminary series of 41 aspirates, cytochemical staining index (% cells staining x mean intensity) related to the receptor concentration determined biochemically on a subsequent biopsy with a correlation coefficient of +0.65. In a second series of 56 aspirates examined after lysis and cytocentrifugation, the correlation coefficient was +0.73. For 14 patients, the response of the primary tumour to endocrine therapy was assessed objectively by serial clinical and mammographic measurements (Forrest et al., 1986) and was found to relate strongly to the cytochemical staining of the initial aspirate. The potential and limitations of this technique are discussed.

Quantification of oestrogen receptors in breast cancer: radiochemical assay on cytosols and cryostat sections compared with semiquantitative immunocytochemical analysis

A radiochemical oestrogen receptor assay on cytosol was correlated with a radiochemical and an immunohistochemical oestrogen receptor assay using cryostat sections from 50 breast cancer specimens. Oestrogen receptors were reliably quantitated in 6 micron cryostat sections with Scatchard analysis using radiolabelled oestradiol, and a good quantitative and qualitative relation with cytosol oestrogen receptor assay was found. Parallel sections were used for routine histological tissue verification and for direct comparison with immunohistochemistry for oestrogen receptor. Specific immunoperoxidase staining with a rat monoclonal antibody was scored by semiquantitative evaluation of the staining intensity of cancer cell nuclei. Oestrogen receptor scoring was highly reproducible when performed by the same observer. The semiquantitative immunohistochemical oestrogen receptor score correlated significantly better with the radiochemical assay on sections than with cytosol assay. Oestrogen receptor in breast cancer can be reliably assayed by semiquantitative evaluation of cryostat sections immunostained for oestrogen receptor, but only if the procedure is adequately standardised. The results underline the importance of cellular heterogeneity as a cause of variation in oestrogen receptor assay evaluation in breast cancer.

Relationship between radioligand binding assay, immunoenzyme assay and immunohistochemical assay for estrogen receptors in human breast cancer and association with tumor differentiation

We have studied the merit of a new enzyme immunoassay (EIA) in relation to the results obtained with a conventional dextran-coated charcoal assay (DCC) of estrogen receptors (ER) in cytosols and nuclear extracts of human breast cancer tissue. The results of the two assays were related to cytosolic progesterone receptor content (PgR), semiquantified ER content in formalin-fixed paraffin embedded tissue specimens and tumor differentiation. The EIA was found stable at low cytosol protein concentrations (0.5 mg/ml). The EIA and DCC assays were highly correlated both in cytosols (r = 0.92, n = 57) and nuclear extracts (r = 0.82, n = 25), but the EIA slightly overestimated the ER values in both ER fractions. A significant correlation between ER in nuclear (ER(N] and cytosolic (ER(C] fractions was established with both assays (DCC: r = 0.90, n = 56; EIA: r = 0.83, n = 24). A qualitative relationship was established between PgR and ER fractions as determined with both assays, the best quantitative association was between PgR and ER(N(DCC] (r = 0.58, n = 34, P less than 0.001). A significant qualitative and quantitative relationship was found between semiquantified ER content in formalin-fixed, paraffin-embedded tissue and ER(C(DCC] (r = 0.88), ER(N(DCC] (r = 0.86], ER(C(EIA] (r = 0.60), ER(N(CIA] (r = 0.64) and PgR (r = 0.65). Finally, we found tumor differentiation to be significantly associated with ER content as determined with all assays except for ER(N(EIA]. We recommend the use of the DCC assay for routine analysis of ER until the clinical correlation of EIA results has been established.

Estrogen and progesterone receptor determinations in breast cancer. Technology, biology and clinical significance

Our present state of knowledge regarding estrogen and progesterone receptors (ER and PgR) has led to changes in treatment strategies: patients without receptors in their tumor tissues cannot be expected to respond to endocrine therapy. Furthermore, groups of patients with specifically good or poor prognoses can be selected. Treatment of the disease now approaches being of a rational rather than of an empirical nature. However, it is imperative that we achieve a considerably higher level of understanding before we can predict, with high probabilities, which patients will benefit from endocrine therapy. Only through a coordinated effort by many centers can we hope to attain this goal. In such collaborations there are several factors that must be taken into consideration if reproducible conclusions are to be reached: a) sampling of the tumor biopsy for analysis, b) potential differences in assay procedures which may affect results, and c) the composition of the population studied. Since the traditionally used ligand binding assay (dextran-coated charcoal (DCC) method) is highly sensitive even to slight modifications in assay procedure, intra- and interlaboratory standardization of receptor analyses is challenging. Accordingly, correlations between receptor status and/or concentrations and the clinical course of the disease from different centers often demonstrate discrepant results. With the greater reproducibility and sensitivity of the newly developed immunoenzymometric assay (IEMA) methods, many of these problems might be solved in the future and inter-center clinical studies will thus be facilitated. In the national Danish Breast Cancer Cooperative Group (DBCG) project, approximately 90% of all patients with primary breast cancer are registered. Estrogen and progesterone receptor (ER and PgR) determinations have been performed on tumor tissue from approximately 30% of these patients in one single laboratory. The results of these analyses are presented here for approximately 4,000 patients in relation to age, menopausal status, tumor size, grade of anaplasia, and lymph node involvement. Biologically and clinically there appear to be three fundamental types of tumor tissues; hormone responsive (ER+PgR+ and ER-PgR+), hormone non-responsive (ER-PgR-), and tissues of a more dubious hormone responsive nature (ER+PgR-), which occur predominantly among postmenopausal patients. Several lines of evidence indicate that among the postmenopausal patients there may be an estrogen binding molecule similar to but distinct from the normal, physiologically functioning ER molecule.(ABSTRACT TRUNCATED AT 400 WORDS)

Estrogen receptors in gastric adenocarcinoma: a retrospective immunohistochemical analysis

Estrogen receptors (ER) in human gastric carcinomas were examined immunohistochemically using a specific monoclonal antibody to human ER. ER-immunoreactivity (ER-IR) was positive in 30 (27.8%) of the 108 gastric carcinomas examined. ER-IR was located in the nucleus of cancer cells. The incidence of ER-IR positive gastric carcinoma was not significantly different between male and female cases. However, the positive tumour cells were observed in 28 (39.4%) out of the 71 poorly differentiated adenocarcinoma, the incidence being significantly higher than that in well differentiated adenocarcinoma (p less than 0.01). There was no significant difference in the incidence of ER-IR between scirrhous carcinoma and non-scirrhous poorly differentiated adenocarcinoma. Synchronous expression of ER and epidermal growth factor receptor was found in 8 of the 26 scirrhous carcinomas (30.8%). Patients with ER-IR positive scirrhous gastric carcinomas showed a much worse prognosis than those with ER-IR negative scirrhous carcinomas.

Relationship between estrogen receptor status in the primary tumor and its regional and distant metastases. An immunohistochemical study in human breast cancer

Treatment of metastatic breast cancer based on the estrogen receptor content (ER) of the primary tumor builds on the assumption that the ER status of the primary tumor and the metastases are largely equal. Studies addressing this question have used ligand-binding assays for ER determination and have consequently been subject to the limitations of this technique. Reported disparity rates have been 20%. In order to avoid some of these limitations, we used an immunohistochemical assay in paraffin-embedded tissue. Among a total of 92 examined regional lymph node metastases, ER status was equal with that of their 37 primaries in 84 cases (91%). Semiquantified ER content was significantly correlated in primary tumor and the metastases (r = 0.67, p less than 0.001). Among a total of 51 distant metastases, equal ER status was found in 44 (86%) cases and a quantitative relationship could not be established. Disparities can be due to methodological errors in the histochemical assay or tumor heterogeneity.

Immunohistochemical analysis of estrogen receptors (ER) using formalin-fixed paraffin-embedded breast cancer tissue: correlation with clinical endocrine response

A new immunohistochemical assay utilizing anti-ER monoclonal antibodies (H 222, Abbott) for detection of ER in formalin-fixed paraffin-embedded breast cancer tissue has been clinically evaluated. It is shown that tumors containing immunoreactive epithelial cells are much better candidates for hormonal manipulation than those without. In addition, primary tumors and corresponding regional lymph node metastases contain qualitatively the same ER pattern. The potentials and limitations of the present method are discussed in relation to other well-known ER assays.

Gynecomastia. Immunohistochemical demonstration of estrogen receptors

Immunohistochemical estrogen receptor (ER) analysis using a monoclonal ER antibody was performed on a total of 30 specimens from 26 patients with gynecomastia. Twenty-six specimens were ER-positive, 3 were ER-negative, and the analysis failed in one case. Immunohistochemical analysis proved more sensitive than biochemical ER analysis in a group of 20 patients, and in a group of 6 patients, the immunohistochemical analysis correlated well with in vitro hormonal sensitivity of the gynecomastic tissue. Semi-quantified ER content was inversely correlated with patient age. There was no relationship between ER content and either histopathologic features or hormonal status. In conclusion, this study demonstrates that the intracellular ER responsible for estrogenic stimulation is present in most gynecomastic tissue specimens, supporting the general assumption that estrogen can be one of the hormones responsible for the development of gynecomastia.

Identification of oestrogen receptors in cells of paraffin-processed breast cancers by IGSS

Oestrogen receptor (ER) analysis of breast cancers by the standard dextran coated charcoal (DCC) method and the oestrogen receptor immunocytochemical assay (ERICA), shows that ERICA is more sensitive. We find that the immunogold-silver staining technique (IGSS), which is used on paraffin sections, is applicable to the ERICA antibody and that the DCC and IGSS methods have comparable sensitivity. Reasons for wishing to develop an improved method for oestrogen receptor localisation in paraffin sections and its advantages are given.