Immunocytochemical detection of progesterone receptor in breast cancer with monoclonal antibody. Relation to biochemical assay, disease-free survival, and clinical endocrine response

Estrogen, Progesterone Receptors and Proliferating Activity Evaluated by Immunocytochemistry in Breast Cancer

The correlation of the most important prognostic indicators was evaluated in 75 breast cancer cases. Estrogen-progesterone receptors and proliferating activity were analyzed by immunocytochemical methods (ER-ICA, PR-ICA, Ki-67). Both steroid receptors were inversely correlated with the proliferating activity (ER-ICA vs Ki-67, p < 0.003; PR-ICA vs. Ki-67, p < 0.0001). No correlation was found between steroid receptors or cell kinetics and tumor size or lymph node status. These findings confirm the relevance of biochemical and kinetic parameters as independent markers in breast cancer and suggest a routine use of the simple immunocytochemical methods in assessing the biological behavior of tumors.

The Significance of c-erbB-2 Overexpression and p53 Expression in Patients With Axillary Lymph Node—Negative Breast Cancer: A Tissue Microarray Study

We conducted this study to examine whether the expression of c-erbB-2 and p53 is the prognostic indicator for patients with early-stage breast cancer in which axillary lymph node metastasis is absent. We examined 326 patients with early-stage breast cancer in which axillary lymph node metastasis is absent. Tissue microarrays were constructed. Following this, immunohistochemical staining was done for estrogen receptor (ER), progesterone receptor (PR), c-erbB2, and p53. The results were as follows: (1) expression of c-erbB-2 was correlated with other clinicopathologic factors (eg, patient's age, presence of menopause, tumor size, histologic and nuclear grade, and presence of hormone receptors such as ER and PR); and (2) expression of p53 was correlated with survival rate, patient's age, presence of menopause, and tumor size. However, these results were not statistically significant. In conclusion, our results indicate that expression of c-erbB-2 and p53 did not have any prognostic value in patients with early-stage breast cancer in which axillary lymph node metastasis is absent.

Breast cancer patients with progesterone receptor PR-A-rich tumors have poorer disease-free survival rates

PURPOSE

No study has yet analyzed whether changes in relative expression levels of progesterone receptor (PR) isoforms A and B in human breast tumors have significance in predicting clinical outcome. Human PRs are ligand-activated nuclear transcription factors that mediate progesterone action. Their presence in breast tumors is used to predict functional estrogen receptors (ERs) and, therefore, also to predict the likelihood of response to endocrine therapies and disease prognosis. The two PR isoforms, PR-A and PR-B, possess different in vitro and in vivo activities, suggesting that in tumors, the ratio of their expression may control hormone responsiveness. In general, PR-B are strong transcriptional activators, whereas PR-A can act as dominant repressors of PR-B and ER. Thus their balance may affect tamoxifen response in breast cancers.

EXPERIMENTAL DESIGN

To determine whether differential expression of the PR isoforms is associated with clinical outcome and hormonal responsiveness, PR-A and PR-B were measured by immunoblot analysis of cell lysates from 297 axillary node-positive breast tumors.

RESULTS

Expression of the two isoforms correlated with each other, as well as with ER. Additional analyses revealed that patients with PR-positive tumors but high PR-A:PR-B ratios, which were often caused by high PR-A levels, were 2.76 times more likely to relapse than patients with lower ratios, indicating resistance to tamoxifen.

CONCLUSIONS

This study suggests that knowledge of the PR-A:PR-B ratio may identify a subgroup of ER-positive/PR-positive patients with node-positive breast cancer that benefit poorly from endocrine therapy.

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.

Comparative analysis of the biochemical and immunohistochemical determination of hormone receptors in invasive breast carcinoma influence of the tumor-stroma ratio

Tumor samples obtained from 106 primary breast cancer patients were examined biochemically (DCCA) and immunohistochemically (IHC) for estrogen (ER) and progesterone receptors (PR) to assess a quantitative relationship between both assays and to study the influence of the tumor-stroma ratio on this quantitative relationship. We used a model of logit transformation of IHC values (% of positive cells) and logarithmic transformation of DCCA values (fmol receptor/mg cytosolic protein). Tumors were subdivided into three categories according to the tumor-stroma ratio (more (t > s), equal amounts (t = s) or less (t < s) tumor than stroma), and the influence of the tumor-stroma ratio was studied using multiple regression analysis. We report a mathematical relationship between the results of the biochemical and immunohistochemical assays for the determination of ER status and PR status in primary breast cancer patients (ER: log DCCA(fmol/mg) = 0.369 logit (IHC(%pos cells)) + 2.328 (r = 0.573; p < 0.0001); PR: log DCCA (fmol/mg) = 0.474 logit (IHC(%pos cells)) + 0, 00 (r = 0.634; p < 0.0001)). In tumors overexpressing ER immunohistochemically (>10% nuclear positivity), median ER-DCCA is significantly higher if the tumor-stroma ratio is greater than 1. As these patients respond to hormonal treatment, depending on the degree of expression of both receptors, this study suggests that the biochemical assay be avoided because this technique is hampered by false-negative or falsely low results due to the loss of morphological information on the tumor-stroma ratio.

Comparison of different antibodies for detection of progesterone receptor in breast cancer

Monoclonal antibodies directed against human estrogen receptor (ER) and progesterone receptor (PR) have been used extensively for biochemical and immunohistochemical detection of receptors independent of hormone-binding assays. These antibodies have been valuable both for experimental work and for detection of receptors in clinical breast cancer specimens. The purpose of this study was to characterize the sensitivity and specificity of different antibodies for detection of PR by immunohistochemistry (IHC) of formalin-fixed paraffin breast carcinoma sections. The panel of twelve antibodies included two new ones (PgR636 and PgR1294) produced prospectively to be resistant to formalin fixation and paraffin embedding. Fifty-nine breast carcinomas, having known PR levels by biochemical ligand-binding assay, were used to prepare multitumor paraffin-embedded tissue blocks for characterization of the PR antibodies. Of all the antibodies tested, both PgR636 and PgR1294 stained the highest percentage of breast carcinomas known to be positive by the biochemical assay (95-98%) and they exhibited the highest concordance with the biochemical assay (88-90%). The PgR636 and PgR1294 antibodies, along with one other, PR 88, also gave the highest intensity of nuclear staining, while PgR636 and PgR1294 stained the highest mean percentage of tumor cell nuclei. Antigen retrieval was not necessary for PR immunostaining by PgR636 and PgR1294 in most tumors and other tissues examined, but did slightly increase the staining intensity. The majority of the other antibodies tested were highly dependent on antigen retrieval; only PR 88 and KD 68 antibodies approached the performance of PgR636 and PgR1294 without antigen retrieval. These results indicate that PgR636 and PgR1294 are optimal antibodies for IHC detection of PR in routine paraffin tissue blocks.

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.

Computer-assisted immunocytochemical determination of breast cancer steroid receptors. Frozen sections vs paraffin sections

Previously we have demonstrated that determination of oestrogen (ER) and progesterone (PR) receptors by immunocytochemical assay (ICA) on frozen sections (FS) and cytological smears with image analysis is effective for evaluating steroid receptors. The aim of this study was to determine concordance between ER and PR assessed by ICA on FS and paraffin sections (PS) both evaluated by image analysis. There were 115 breast carcinomas selected. For all cases, ER and PR determination was performed on FS and PS. Computer-assisted image analysis was performed using CAS 200. Results were expressed as percent positive area of neoplastic nuclei compared with total nuclear area of the examined neoplastic cells. Good correlation was demonstrated for both ER (r=0.759; concordance=83.4%) and PR (r=0.800; concordance=87.8%). The unexpected relatively low concordance for ER led to further investigations. We divided the 115 cases in two groups. The first group included specimens from our hospital; the second group specimens from suburban hospitals. In the first group there was better correlation for both ER (r=0.897) and PR (r=0.915) with a concordance of 91.5% and 93.6%, respectively. In the second group, correlation was worse for both ER (r=0.724) and PR (r=0.708), with a concordance of 77.9% and 83.9% respectively. From analysis of discordant cases we conclude that reduction in correlation and concordance with increased false negative cases in group 2 are probably due to delayed fixation. Our data suggest that ICA with automated image analysis is efficient in evaluating ER and PR on paraffin section only when the tumour samples are correctly fixed.

Assessment of Tissue Estrogen and Progesterone Receptor Levels: A Survey of Current Practice, Techniques, and Quantitation Methods

The assessment of steroid hormone receptors in resected breast carcinoma tissue is currently the standard of practice. The traditional method for assessment of receptor status is the ligand binding assay. More recently, immunohistochemistry (IHC) has become a popular method for such testing. Despite the widespread use of IHC and the availability of many antibodies, standardization of quantitative IHC for assessment of estrogen and progesterone receptors has not been achieved. While the College of American Pathologists (CAP) offers a Quality Assurance (QA) program for IHC quantitation of estrogen receptor (ER) and progesterone receptor (PgR), no universal standard is currently recognized in assessment of ER and PgR by IHC. We surveyed 300 laboratories within the United States for their current practices regarding the assessment of ER and PgR status in breast cancer tissue specimens. Eighty usable responses were received. Forty-nine (61%) laboratories performed the assay in-house, while the remainder sent the material out for assay. All responding laboratories performing their steroid receptor analysis in-house used the IHC technique. Forty-three (80%) laboratories answering the question on material accepted for analysis performed the assay only on paraffin-embedded material, three (6%) used either paraffin block or frozen material, and two (4%) used only frozen material. Eighty-eight percent of laboratories performing steroid receptor analysis in-house used a manual quantitation technique. Four (8%) used computer-assisted image analysis, and a single laboratory used laser scanning cytometry. Eight different antibodies were used among the 44 laboratories documenting the antibody supplier, and for any given commercially prepared antibody a wide variety of dilutions were used, with the exception of the standard solution used with the Ventana antibody. Of the laboratories using manual estimation techniques, 61% simply estimated the percentage of positive cells, 29% evaluated both the intensity of staining and percentage of nuclei staining, 6% used formal H-score analysis, 2% evaluated only intensity of nuclear staining, and 2% mainly counted the percentage of nuclei staining for ER but used a formal H score in the assessment of PgR. Cutoff points for the separation of positive and negative results varied widely, with some laboratories assessing any demonstrable positivity as a positive result, while others required as many as 19% of the nuclei to stain before a specimen was declared positive. Standardization techniques differed considerably among laboratories. Eighty-six percent used the CAP program for QA. While all laboratories utilized some form of intralaboratory control for assessment of ER and PgR, the nature of that control varied from laboratory to laboratory. Our survey indicates that a majority of laboratories perform their steroid hormone receptor analysis in-house using IHC. There is considerable variability in the antibodies utilized, the dilutions applied, and the quantitation method and level of expression used to dichotomize specimens into positive and negative groups. Finally, no universal control for interlaboratory standardization appears to exist.

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.

Chromosome 11 aneuploidy detected by fluorescent in situ hybridization (FISH) in breast cancer: relation with progesterone receptor expression

Progesterone receptor (PR) expression is known to be impaired in breast cancer. As the PR gene is located on chromosome 11 which is also often affected, we studied their relationship in 15 patients with breast carcinoma. Tumoural imprints were used for PR immunocytochemistry and for FISH with chromosome 11 centromeric probes. Distribution profiles of chromosome 11 number in PR+ and PR- cell populations were examined. No difference in the number of chromosome 11 was found between PR+ and PR- breast tumours. Thus, loss of PR expression in breast cancer cannot be explained only by loss of chromosome 11; other genetic or non-genetic mechanisms should be advanced.

Comparison of immunohistochemical and biochemical measurement of steroid receptors in primary breast cancer: evaluation of discordant findings

Tumor samples of 240 patients with primary breast cancer were biochemically and immunohistochemically investigated for estrogen receptors (ER) and, in 130 of the samples, for progesterone-receptors (PgR) in order to examine reasons for discordant findings. The biochemical (DCCA) and immunohistochemical assays (ICA) yielded positivity in 71% for ER, and in 44% for PgR. Concordant ER-DCCA and ER-ICA results were obtained in 84%; two thirds of the discordant ER-findings manifested as DCCA-neg/ICA-pos. Concordance in the case of PgR amounted to 72%, and of the discordances 60% were DCCA-neg/ICA-pos. Significant association with postmenopausal status existed only for ER positivity in ICA (p = 0.01), whereas ER-DCCA, PgR-DCCA and PgR-ICA were all more or less independent of the menopausal status. The frequency of discordances was independent of menopausal status. Discordance for ER-assays increased significantly near the respective cut-off point; this was not unequivocally true for PgR-assays. The correlation of tumor types of sparse cellularity, as well as prominent stroma content ('scirrhous carcinoma') with increased frequency of the constellation DCCA-neg/ICA-pos was of borderline significance for PgR (p = 0.06), but not for ER. The percentage of discordant ER-findings, figuring as DCCA-neg/ICA-pos, was statistically significantly increased in locally advanced breast cancer (p = 0.03). Fibrocystic disease in peritumoral breast tissue had no impact on receptor-assay discordance. In any case, the models derived from theoretical thought, laboratory data and singular observations can only in part explain the discordance in steroid receptor values measured with different methods.

Immunoperoxidase staining for estrogen and progesterone receptors in archival formalin fixed, paraffin embedded breast carcinomas after microwave antigen retrieval

Immunoperoxidase staining was performed for estrogen and progesterone receptors in 93 cases of primary breast carcinoma. Breast tumor samples were fixed in formalin and embedded in paraffin. Antigen retrieval was performed by microwave heating in citrate buffer, pH 6.0, using precisely defined and reproducible conditions. The cases studied included material from the current year and from paraffin blocks retrieved from archival storage dating back to 1981. In all cases, estrogen and progesterone receptor values determined by biochemical assay were available for comparison with the immunohistochemical results. We found 94% agreement of results between the two methods.

Steroid receptor measurement in breast cancers: comparison between ligand binding and enzyme-immunoassay in cytosolic and nuclear extracts

We have analysed cytoplasmic and nuclear extracts of breast-cancer tissue from a total of 799 patients, measuring both oestrogen and progesterone receptors (ER, PR) using either the ligand binding assay (LBA) or the enzyme immunoassay technique (EIA). Mean and median receptor levels were much lower than those widely reported by others. For ER, this may in part be a consequence of the younger median age of the patient group. The frequency of positivity, using consensus cut-off values for clinical evaluation, was also lower than that reported by the EORTC Receptor Study Group. Although the measurements comparing the 2 methods were statistically correlated in terms of positivity, based on the above criteria for clinical assessment, concordance was considered to be relatively poor, particularly for ER when assayed in the same samples by the 2 methods. In cytosolic but not nuclear extracts, the LBA method gave a higher median value for ER than the EIA (except in the group that had EIA values greater than 15 fmol/mg protein); for PR, median values were higher with EIA in both cell fractions. There was an excellent correlation between receptor amounts in cytosolic and nuclear extracts for both ER and PR using the EIA; this was significantly better than with LBA. We also observed a correlation between ER and PR in both cytosolic and nuclear fractions which was most pronounced when the analysis was done by EIA. The amounts of ER in the cytosolic fraction were also correlated with the those of PR in the nuclear fraction and ER in the nuclear fraction with PR in the cytosolic fraction, but only when the EIA method was used. We conclude that the EIA method appears to be more sensitive and gives biologically more reliable results. However, the disagreement between the methods may be due to legitimate recognition of altered forms of the receptor and may be of biological significance. Although the presence of receptor in the cytosolic fraction is artifactual, its measurement by EIA does parallel the amounts of nuclear receptor, which may be a more relevant biological parameter.

A prospective analysis of immunohistochemically determined hormone receptors and nuclear features as predictors of early recurrence in primary breast cancer

The immunohistochemically determined receptor status, as well as first-generation risk factors (tumor size, lymph node status, histologic grading including subfactors, tumor histology, and biochemically determined receptor status) were prospectively analyzed in 288 cases of primary breast cancer for their impact on recurrence-free survival (RFS) and overall survival (OS) after a median observation period of 41 months. Immunohistochemically (ER-ICA) and biochemically determined estrogen receptors (ER-DCC), as well as tumor size, lymph node status, histologic grading, mitotic rate, and nuclear polymorphism, were of prognostic value for recurrence-free survival and/or overall survival. In multivariate analysis, lymph node status, tumor size, and mitotic rate proved to be independent prognosticators; ER-ICA showed significance in the univariate analysis which dropped, however, when multivariate analysis was applied. The prognostic power of histologic grading in our series seemed to depend mainly on the subfactors which relate to nuclear features.

Immunohistochemical detection of progesterone receptors in paraffin sections. A novel method using microwave oven pretreatment

The benefits of microwave oven pretreatment of formalin-fixed routinely processed paraffin sections were assessed using citric acid solution to demonstrate progesterone receptors (PR). Parallel frozen and paraffin sections from 25 cases of breast cancer were stained with the PR-ICA kit (Abbott). Compared with untreated paraffin sections a great enhancement of PR immunostaining occurred after microwave irradiation. In 21 cases the percentage of positively stained tumor cell nuclei in microwave oven-pretreated paraffin sections was practically identical to that in the frozen ones. After microwave irradiation the PR score in paraffin sections was in three cases higher than in the frozen material. In comparison with the frozen sections, only one tumor of 25 showed a lower percentage of stained malignant cells after the irradiation. It is concluded that microwave oven pretreatment is a simple, reliable and reproducible method to detect PR in routinely fixed paraffin-embedded tissues.

Prognostic factors in early breast carcinoma

Several investigators, the SEER data, and the ECOG/Intergroup study have shown that patients with small tumors (< 0.5 cm) have a recurrence rate of less than 2%, compared to 20-25% for large tumors (> or = 5 cm). Nuclear grade and tumor differentiation are established indicators; however, the interobserver lack of concordance has thwarted their use in clinical trials. The presence of peritumoral lymphatic and blood vessel invasion (PLBI) is associated with a relative risk of recurrence of 4.7. The predictive value of the presence of hormone receptors in tumors is associated with a favorable disease free and overall survival difference of 8-10%; however, this advantage is being eroded by the early appearance of other factors, such as the epidermal growth factor receptor (EGFR), proliferative capacity (S-phase), nuclear grade, and HER-2/neu oncogene. Concordance among the different methods of hormone-receptor assay (immunocytochemical, sucrose gradient, and dextran-coated charcoal) is essential to refine the true value of these factors. DNA flow cytometry measurements of ploidy (DNA content) and S-phase fraction are the most characterized of the prognostic factors. There are conflicting reports regarding the clinical significance of ploidy status, while measurements of S-phase fraction clearly indicate a robust association with disease free and overall survival. Our data continue to show that S-phase, but not ploidy, can predict time to recurrence significantly in untreated patients, even when data are stratified for tumor size. HER-2/neu oncogene is expressed in about 50% of ductal carcinoma in situ and 14% of invasive ductal carcinoma. The presence of this oncogene at high copy number may be a useful independent marker of poor prognosis and may be associated with drug resistance and correlated with tumor recurrence and shorter survival. EGFR could be measured in most breast tumors, and the level of its expression has inversely correlated with estrogen receptor protein expression. The value of EGFR as a predictor of prognosis remains controversial and is still being investigated. Cathepsin-D provides a provocative biologic rationale but is hindered by different and incongruent methods of analysis. The majority of large studies with more than 3-years' follow-up suggests that high cathepsin-D levels may be predictive of greater recurrence and lower survival. Angiogenesis has been implicated as a critical component of the metastatic process. Early studies show that tumor angiogenesis is an independent and highly significant prognostic indicator, and its presence may suggest the selection of "anti-angiogenic therapy."(ABSTRACT TRUNCATED AT 400 WORDS)

Comparison of estrogen and progesterone receptor status to lymphocyte immunity against tumor antigens in breast cancer patients

Estrogen (ER) and progesterone receptor (PgR) content of tumors were determined by both the dextran-coated charcoal (DCC) cytosol and immunocytochemical assays (ICA), and these hormone receptor results were compared to lymphocyte immunity against tumor antigen(s) for 52 breast carcinoma patients. Hormone receptor analysis by both methods demonstrated that 60% of the patients' tumors had ERs, while 44% were positive for PgRs. The ICA procedure was more sensitive than the cytosol technique for determining PgR content of the tumors. This increased sensitivity was not observed for ER by ICA. Patient age, tumor size, and nodal status were not related to the ER and PgR receptor status. A total of 21/52 (40%) of the patients had positive lymphocyte immunity against tumor antigen. This immunity was independent of patient age, tumor size, and nodal status. There was no significant relationship between lymphocytic immunity against tumor antigen and ER or PgR content of tumors, suggesting that patient lymphocyte immunity against tumor is independent of hormone receptor status. This is further evidence that lymphocyte immunity against tumor antigen status is an independent prognostic indicator that may be useful in the selection of a subset of node negative patients for adjuvant chemotherapy.

Immunohistochemical detection of female sex hormone receptors in meningiomas: correlation with clinical and histological features

Sixty-one meningiomas from 60 patients were screened for estrogen receptors and progesterone receptors (PgR) with monoclonal antibodies in an immunohistochemical assay. In addition, 43 of the cases were evaluated for tumor size and peritumoral edema, as seen on computed tomographic scans and magnetic resonance images. Sixty-one percent of the tumors contained significant amounts of PgR, whereas no estrogen receptor-positive tumor was observed. Thirteen percent of all tumors were classified as nonbenign variants (atypical and anaplastic meningiomas) and were more frequently found in male patients (P < 0.05). Nonbenign tumors more frequently showed an absence of PgR (P < 0.05), and there was a tendency for PgR-negative tumors to be larger than PgR-positive ones. No correlation was found between PgR status and edema. It is concluded that PgR status in meningiomas is related to tumor differentiation and may be of prognostic value with regard to biological behavior and clinical outcome.

Immunohistochemical and biochemical measurement of estrogen and progesterone receptors in primary breast cancer. Correlation of histopathology and prognostic factors

OBJECTIVE

The authors investigated correlations of estrogen-receptor and progesterone-receptor with conventional risk factors as well as histopathology in patients with primary breast cancer.

SUMMARY BACKGROUND DATA

Immunohistochemically determined hormone receptors have gained importance as prognosticators in primary breast cancer, but their definitive role has not yet been evaluated.

METHODS

Tumor samples from 299 patients were examined for estrogen and progesterone receptors by biochemical and immunohistochemical assay. Correlations with established risk factors (tumor size, lymph node status, menopausal status, grading including subfactors) and histopathology were analyzed.

RESULTS

The estrogen receptor, determined by immunohistochemical method revealed positivity in 80.6% of patients; biochemical measurement yielded 76.2% positive results. The progesterone receptor measured by immunohistochemistry yielded 61.3% positivity versus 55.8% detected by biochemical analysis. Invasive lobular, tubular, and ductal invasive carcinoma with prominent stroma content ("scirrhous carcinoma") rather than ductal invasive carcinoma was more frequently estrogen-receptor positive with immunohistochemistry than with biochemical assay. For progesterone receptor, the same pattern of positivity was seen with immunohistochemical assay. With progesterone receptor determined biochemically, "scirrhous" and lobular carcinoma showed positive results in a lower proportion than invasive ductal and tubular carcinoma. Significant correlations were observed between the estrogen-receptor status, the histologic grade of malignancy, nuclear polymorphism, and the rate of mitosis with both methods (p < 0.001 respectively). Different correlations were found between tumor size, menopausal status and estrogen receptor status with both assays respectively. For the progesterone receptor status, immunohistochemistry yielded significant correlations with the histologic grade of malignancy, nuclear polymorphism, rate of mitosis (p < 0.001 respectively) as well as growth pattern (p < 0.01), while biochemical analysis revealed a correlation with nuclear polymorphism (p < 0.05). The correlation analysis of both components of the immunoreactive score revealed a more significant impact of percentage of positive cells than of staining intensity.

CONCLUSIONS

Immunohistochemistry detected a closer correlation between prognostic factors and receptor data than biochemical analysis.

Interference of thyroperoxidase on immuno-cytochemical determination of steroid receptors in thyroid tissue

The presence of sexual steroid receptor proteins in thyroid tissue has been previously demonstrated by biochemical means. The aim of this study was to determine the estrogen (ER) and progesterone (PR) receptors in malignant (12 papillary and 1 follicular carcinoma) and nonmalignant (19 multinodular goiters, 1 Graves' disease, 1 Hashimoto's thyroiditis) thyroid diseases using immunocytochemical assay employing monoclonal anti-ER and anti-PR antibodies and the peroxidase-antiperoxidase technique. Positive results were obtained in 24/34 (70%) for ER (ER-ICA+) and 22/34 (64%) for PR (PR-ICA+). To evaluate the possible interference of thyroperoxidase in the immunostaining, in consecutive sections of a positive specimen, primary antibody or primary antibody plus bridging antibody or PAP complex was omitted. Using these modified procedures, staining distribution was similar to that obtained by the standard procedure: in contrast, no staining was found in the positive control, i.e. a breast cancer specimen. The inhibition of the endogenous peroxidase caused a loss of staining in both the standard and modified procedures on thyroid specimens; no staining modification was obtained in the positive control. These results suggest that the staining observed in thyroid tissue is not specific and related to the activity of thyroperoxidase on chromogen solution. The complete loss of staining after peroxidase inhibition appears to be in contrast with the results obtained by biochemical method, and different antigenicity of thyroid receptors in comparison with breast receptors may explain this discrepancy.

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.

Immunocytochemical determination of estrogen and progesterone receptors in human endometrial adenocarcinoma cells (Ishikawa cells)

The regulation of both estrogen and progesterone receptor levels in human endometrial adenocarcinoma cells of the Ishikawa line was investigated immunocytochemically by using monoclonal antibodies. Positive staining for estrogen and progesterone receptors was observed in the nuclei of Ishikawa cells. Intercellular heterogeneity in receptor content was evident from the presence of receptor-positive or -negative cells and from differences in staining intensity of positive cells. Quantitative analysis was performed by scoring the staining intensity and the proportion of positively stained cells. The time and dose-dependent stimulatory effect of estradiol added to culture media on progesterone receptor levels was studied by applying both immunocytochemical and biochemical methods. Estradiol at 10 nM (optimal concentration) increased the intensity score for PR from an initial value of 10.1 to 78.3 after 72 h incubation, and the proportion of the positive staining cells from 6.7 to 42.7%. Promegestone (R5020) was effective at 1 microM concentration in decreasing the intensity score for ER from 31.1 to 14.6 after 72 h exposure and the proportion of positive cells from 19.0 to 11.4%.

Oestrogen receptor assay of breast cancer by immunocytochemistry of fine needle aspirates

Sixty-five patients with operable breast cancer were studied to assess the reliability of immunocytochemical analysis of oestrogen receptor (ER-ICA) in specimens obtained by percutaneous fine needle aspiration. Results obtained with the commercially available ER-ICA kit were compared with those obtained by the routine biochemical radioligand assay of oestrogen receptor (ER) on excised tumour specimens. Fifty-two of 65 percutaneous aspirates were evaluable. Of these, thirty-five (67%) were ER positive by the radioligand method. ER-ICA was found to be a reliable method for oestrogen receptor assay, with a high concordance (90.4%) between it and the radioligand essay. The ER-ICA assay had a sensitivity of 89%, specificity of 94%, positive predictive value of 97% and negative predictive value of 80%. ER-ICA assay performed on material obtained by fine-needle aspiration is a reliable method of ER assay. It can replace formal biopsy for patients with inoperable primary tumours or accessible metastases.

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.

Steroid hormone receptors

In the three decades since the original discovery of receptors for steroid hormones, much has been learned about the biochemical processes by which these regulatory agents exert their effects in target tissues. The intracellular receptor proteins are potential transcription factors, needed for optimal gene expression in hormone-dependent cells. They are present in an inactive form until association with the hormone converts them to a functional state that can react with target genes. Transformation of the receptor protein to the nuclear binding form appears to involve the removal of both macromolecular and micromolecular factors that act to keep the receptor form reacting with DNA. Much of the native receptor is present in the nucleus, loosely bound and readily extractable, but for some and possibly all steroid hormones, some receptor is in the cytoplasm, perhaps in equilibrium with a nuclear pool. Methods have been developed for the stabilization, purification, and characterization of receptor proteins, and through cloning and sequencing of their cDNAs, primary structures for these receptors are now known. This has led to the recognition of structural similarities among the family of receptors for the different steroid hormones and to the identification of regions in the protein molecule responsible for the various aspects of their function. Monoclonal antibodies recognizing specific molecular domains are available for most receptors. Despite the knowledge that has been acquired, many important questions remain unsolved. How does association with the steroid remove factors keeping the receptor protein in its native state, and how does binding of the transformed receptor to the response element in the promoter region enhance gene transcription? Once it has converted the receptor to the nuclear binding state, is there a further role for the steroid in modulating transcription? Still not entirely clear is the involvement of phosphorylation and/or dephosphorylation in hormone binding, receptor transformation, and transcriptional activation. Less vital to basic understanding but important in the overall picture is whether the native receptors for gonadal hormones are entirely confined to the nucleus or whether there is an intracellular distribution equilibrium. With the effort now being devoted to this field, and with the application of new experimental techniques, especially those of molecular biology, our understanding of receptor function is progressing rapidly. The precise mechanism of steroid hormone action should soon be completely established.

Comparison of microscopic imaging strategies for evaluating immunocytochemical (PAP) steroid receptor heterogeneity

Receptogram analysis was compared with three other imaging strategies for immunocytochemical assay of estrogen receptors. These included nuclear-specific methods for analysis of nuclear integrated optical density (IOD) or mean optical density (MOD) histograms, and field-specific methods, where the pixel optical density (POD) histogram was evaluated for the composite nuclear phase. Measurements in culture and in breast cancer cryosections were treated separately to isolate geometric considerations. In culture receptograms the modality of IOD and MOD histograms and their bivariate contour maps revealed one, two, or more subpopulations with discrete receptor content and concentration. However, when the field of nuclei was imaged as a whole, regardless of the number of subpopulations, POD histograms showed two minima, defining three intranuclear phases. This was due to mottling and variegation of intranuclear chromatin and nucleolar immunostaining and not to differences between nuclei. These limitations were also revealed in breast cancer sections. In POD histograms, % unstained pixels did not provide a reliable estimate of % receptor negative nuclei, as determined by their enumeration. In sections, correction of IOD for nuclear volume variability was essential to suppress artifactual peaks not representing differences in receptor content. This was achieved by multiplying nuclear IOD by the spherical nuclear radius (S) of individual slab sections. Peaks of IOD(S) then reflected receptor content on a true ratio scale. Only receptogram analysis, which incorporates these strategies, permitted objective evaluation of receptor heterogeneity at the level of tumor subpopulations.

Immunocytochemical estrogen and progestin receptor assays in breast cancer with monoclonal antibodies. Histopathologic, demographic, and biochemical correlations and relationship to endocrine response and survival

Breast cancer specimens from 600 women were assayed for estrogen receptors (ER) using an immunocytochemical assay (ICA) employing the monoclonal antiestrophilin antibody H222 Sp gamma. Results showed significant correlation with biochemical ER determinations as well as with tumor grade and menopausal status. In 449 cases, results of progesterone receptor assay by ICA using the monoclonal anti-PgR antibody KD 68, also correlated significantly with biochemical PgR measurements. The ERICA/PgRICA positivity was significantly more frequent in postmenopausal white women. Colloid carcinomas were most likely to be ERICA positive and PgRICA positive whereas medullary carcinomas were most often negative. In 47 patients with advanced mammary carcinoma, results of ERICA and PgRICA were more closely related to endocrine response than those of ER and PgR by dextran-coated charcoal assay (DCC). In 339 women with Stage I or Stage II breast cancer, ERICA was significantly associated with disease-free survival. Analysis by Cox's proportional hazard model, however, showed PgRICA to be the best predictor of survival and disease-free survival in 197 women at the same stages of disease. These data indicate that ICA is more predictive of prognosis than biochemical ER and PgR. The ease of ICA performance coupled with these results indicate that the method is an acceptable substitute for DCC in analyzing breast cancers for ER/PgR.

Demonstration of progesterone receptors in paraffin wax sections of breast carcinoma

Several immunohistological methods for the demonstration of progesterone receptors were tried on routinely processed paraffin wax sections of breast carcinoma, using Abbott's PgR-ICA monoclonal antibody. The best results were obtained with the avidin-biotin-immunoperoxidase complex method with no prior trypsinisation or DNAse digestion, and with imidazole added to the final diaminobenzidine developing solution. A simple semiquantitative scoring system was used to assess the staining results which were then compared with the results obtained by a standard dextran-coated charcoal biochemical assay. Of 31 cases examined, the results of the two methods were concordant in 25 (81%) of cases. This is near the higher end of the concordance range obtained by several other authors using frozen sections. The discordance encountered in a few cases was possibly the result of sampling errors which are more likely to occur with the chemical rather than the histological method. It is concluded that the method described here is fairly reliable and would greatly simplify the process of assessment of progesterone receptors in breast, and possibly other tumours.

A clinical evaluation of nuclear estrogen receptors combined with cytosolic estrogen and progesterone receptors in breast cancer

Breast cancer tissue from 95 women was simultaneously assayed for three receptors: cytosolic estrogen (CER), cytosolic progesterone (CPR), and nuclear estrogen (NER). The main objective was to determine whether the addition of NER assay to the currently accepted practice with only CER and CPR could improve the predictive capacity of receptors. Forty-two patients were studied for response to hormone therapy and 95 patients were studied for survival; the median follow-up period was 73 months (range, 8 to 300 months). The incidence of CER+, CPR+, and NER+ was 74%, 70%, and 52%, respectively. Each receptor appeared more frequently, although not significantly so, in higher age groups. Forty percent of tumors had all three receptors positive and 14% had all negative; the remaining tumors showed all possible combinations of receptors. Both the rate of response and survival curves among 70 patients with CER+ did not show any significant difference whether NER was positive or negative. Also, among 38 patients with CER+, CPR+, and NER+, there was no significant difference in the clinical outcome as compared to 17 patients with CER+, CPR+, and NER-. Among 25 patients with CER- the rare occurrence of NER+ in only three patients did not suggest any clinical implication. It is concluded, therefore, that on overall clinical grounds the current series does not support the addition of NER assay whenever data is available on both CER and CPR.

Discordant results between radioligand and immunohistochemical assays for steroid receptors in breast carcinoma

Surgical biopsy specimens of 179 breast carcinoma were studied by steroid-binding and immunohistochemical assays or oestrogen and progesterone receptors (ER, PR) in order to explore reasons for discordant results between the two assay types. Receptor statuses in 18% of ER assays and 30% of PR assays were in disagreement. Immunohistochemistry-positive steroid-binding-negative status predominated among the discordant ER assays, while the discordant PR assays displayed the opposite situation. In discordant assays receptor concentration was significantly more often close to the cut-off (10-50 fmol mg-1) than in the concordant ones. Low binding affinity (high Kd) was also significantly associated with disagreeing assay results. These observations clearly indicate that immunohistochemical ER and PR assays measure high-affinity binding components (i.e. type I receptors) in steroid-binding assays. ER but not PR assays in premenopausal women disagreed more often than those in post-menopausal women. Such factors as histological type, specimen size in steroid-binding assay, grade of malignancy and tumour necrosis were statistically unrelated to agreement or disagreement of receptor assays.

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.

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.

Immunohistochemical versus biochemical estrogen-receptor and progesterone-receptor analysis: correlation with histological parameters

Human breast carcinomas were evaluated for estrogen and progesterone receptors by immunohistochemistry using monoclonal anti-receptor antibodies (n = 267) and by cytosol steroid-binding assays (n = 212). The estrogen and progesterone receptor contents of the tumors correlated with histological features of differentiation, such as histological and nuclear grade, and with the amount of tumor necrosis and lymphoid infiltration. The correlation of immunohistochemically determined steroid receptor values with histological characteristics was somewhat better than that of biochemically assessed concentrations.

Immunohistochemical determination of estrogen and progesterone receptors in human breast carcinoma. Correlation with histopathology and DNA flow cytometry

Human breast carcinomas (n = 232) were evaluated for estrogen and progesterone receptors (ER, PR) by immunohistochemical study and by cytosol steroid-binding assay (n = 185). The staining was scored (histoscore) by estimates of relative nuclear staining intensity and the percentage of positively stained carcinoma cells. Of the invasive ductal carcinomas 72% were ER-positive and 55% were PR-positive. The invasive lobular, intraductal, tubular, and mucinous carcinomas were the most frequent ER-positive tumor types, whereas comedo and medullary carcinomas only rarely contained ER. Progesterone receptor was most frequently present in intraductal, tubular, and mucinous carcinomas. Better differentiated tumors with lower histologic grade were significantly associated with high prevalence of immunohistochemically determined ER and PR (P less than 0.0001). Proliferative cell fraction, determined by DNA flow cytometric study (n = 63), was inversely related to ER (P = 0.03) and PR (P = 0.05) status. Aneuploidy was independent of ER or PR content.