Heterogeneity of estrogen binding sites in breast cancer: morphologic demonstration and relationship to endocrine response

p66 Shc and tyrosine-phosphorylated Shc in primary breast tumors identify patients likely to relapse despite tamoxifen therapy

Introduction

Shc adapter proteins are secondary messenger proteins involved in various cellular pathways, including those mediating receptor tyrosine kinase signaling and apoptosis in response to stress. We have previously reported that high levels of tyrosine-phosphorylated Shc (PY-Shc) and low levels of its inhibitory p66 Shc isoform are strongly prognostic for identifying both early node-negative and more advanced, node-positive, primary breast cancers with high risk for recurrence. Because aberrant activation of tyrosine kinases upstream of Shc signaling proteins has been implicated in resistance to tamoxifen – the most widely prescribed drug for treatment of estrogen receptor-positive breast cancer – we hypothesized that Shc isoforms may identify patients at increased risk of relapsing despite tamoxifen treatment.

Methods

Immunohistochemical analyses of PY-Shc and p66 Shc were performed on archival primary breast cancer tumors from a population-based cohort (60 patients, 9 relapses) and, for validation, an independent external cohort (31 patients, 13 relapses) in which all patients received tamoxifen as a sole systemic adjuvant prior to relapse.

Results

By univariate and multivariate analyses, the Shc proteins were very strong and independent predictors of treatment failure in both the population-based cohort (interquartile hazard ratio = 8.3, 95% confidence interval [CI] 1.8 to 38, P = 0.007) and the validating cohort (interquartile relative risk = 12.1, 95% CI 1.7 to 86, P = 0.013).

Conclusion

These results suggest that the levels of PY-Shc and p66 Shc proteins in primary tumors identify patients at high risk for relapsing despite treatment with tamoxifen and therefore with further validation may be useful in guiding clinicians to select alternative adjuvant treatment strategies.

2-Pyridin-2-yl-1H-indole derivatives: Synthesis, estrogen receptor binding affinity, and photophysical properties

A series of novel 2-pyridin-2-yl-1H-indole derivatives (4a-f) was prepared by intramolecular cyclodehydration of alpha-anilinyl (or 3-anisidyl)-2-pyridin-2-yl-ethanones (2a-f) and their optical spectroscopy and estrogen receptor (ER) binding properties were studied. These compounds showed long wavelength fluorescent emission, which is sensitive to solvent polarity and pH, while indol-6-ols 4b, e, and f displayed reasonably good binding affinities to ER.

Phosphoglycerate mutase, 2,3-bisphosphoglycerate phosphatase, creatine kinase and enolase activity and isoenzymes in breast carcinoma

We have compared the levels of phosphoglycerate mutase (EC 5.4.2.1), 2,3-bisphosphoglycerate phosphatase (EC 3.1.3.13), creatine kinase (EC 2.7.3.2) and enolase (EC 4.2.1.11) activities and the distribution of their isoenzymes in normal breast tissue and in breast carcinoma. Tumour tissue had higher phosphoglycerate mutase and enolase activity than normal tissue. Creatine kinase activity was higher in seven out of 12 tumours. In contrast 2,3-bisphosphoglycerate phosphatase activity was lower. Phosphoglycerate mutase, enolase and 2,3-bisphosphoglycerate phosphatase presented greater changes in the oestrogen receptor-negative/progesterone receptor-negative breast carcinomas than in the steroid receptor-positive tumours. Determined by electrophoresis, type BB phosphoglycerate mutase, type BB creatine kinase and alpha alpha-enolase were the major isoenzymes detected in normal breast tissue. Types alpha gamma and gamma gamma enolase, types MB and MM phosphoglycerate mutase were detected in much lower proportions. In tumours a decrease of phosphoglycerate mutase isoenzymes possessing M-type subunit and some increase of enolase isoenzymes possessing gamma-type subunit was observed. No detectable change was observed in the creatine kinase phenotype.

Synthesis of 2-[(18)F]Fluoroestradiol, a Potential Diagnostic Imaging Agent for Breast Cancer: Strategies to Achieve Nucleophilic Substitution of an Electron-Rich Aromatic Ring with [(18)F]F(-)

To improve the pharmacokinetics of fluorine-18 labeled estrogens to be used as receptor-based imaging agents for the identification and staging of estrogen-receptor-positive breast carcinoma, we wanted to synthesize 2-[(18)F]fluoroestradiol. This compound has high affinity for the estrogen receptor and also binds very well to sex hormone binding globulin, a protein thought to protect estrogens from metabolism and deliver them to target tissues. We anticipated that this compound might have increased tumor uptake and reduced uptake in the liver. The synthesis of a [(18)F]fluoroaryl estrogen at the high specific activity, no-carrier-added level requires the use of [(18)F]F(-) as a precursor. Several strategies were explored for the synthesis of a [(18)F]fluoroaryl estrogen. The synthesis of 2-[(18)F]fluoroestradiol was eventually achieved by [(18)F]fluoride ion displacement of a trimethylammonium leaving group at C-2 of an estrogen, with additional activation being provided by a 6-keto group which was subsequently removed by reduction. Incorporation yields of fluorine-18 were between 20% and 50%. The potential of this new radiopharmaceutical as an imaging agent is being evaluated in an appropriate animal model.

Effects of tamoxifen on human breast cancer cells in vitro

Long-term treatment of the estrogen sensitive human breast cancer cell line EFM-19 with the antiestrogenic compound Tamoxifen resulted in a variant line EFM-19 T, which was stimulated by Tamoxifen. Estrogen receptor analysis by radioligand assay (charcoal method), revealed a 2.5 fold higher receptor concentration in EF-19 T cells than in the parental EFM-19 cell-line. As demonstrated with the immunocytochemical assay (ER-ICA) only 60% of the parental EFM-19 cells were estrogen receptor positive, whereas 98% of the EFM-19 T cells expressed estrogen receptor protein. In addition, receptor content per cell was higher in the Tamoxifen treated subline than in the parental cell line. Analogous with the growth promoting effect of Tamoxifen on EFM-19 T cells, Tamoxifen acted like estrogen leading to a down regulation of cellular estrogen receptor concentration. The partial growth dependency of the EFM-19 T cells on the presence of Tamoxifen demonstrates estrogenic effects of Tamoxifen and explains the withdrawal response obtained in the treatment of breast cancer patients when remission occurs after termination of ineffective treatment with Tamoxifen.

Characterization of the spectroscopic properties of a tetrahydrochrysene system containing a rigidified hydroxynitrostilbene chromophore: an inherently fluorescent ligand designed for the estrogen receptor

A tetrahydrochrysene system that embodies a hydroxy- and nitro-substituted stilbene chromophore held rigidly near planarity by the tetracyclic nature of the compound was prepared as a fluorescent ligand for the estrogen receptor. It shows strong solvent-dependent fluorescence at long wavelengths. The solvent polarity dependence suggests that the fluorescence arises from an excited state with much n pi * character in cyclohexane; stronger emission comes from an intramolecular charge transfer state that has lower energy in more polar solvents, and finally progressive quenching of the charge transfer state occurs in solvents of higher polarity. The quenching effect is particularly evident in protic solvents. In water, however, the compound shows fluorescence of unusually high energy for an intramolecular charge transfer state, which suggests that photochemistry may be occurring. In solutions of gamma-cyclodextrin, emission from the nitrotetrahydrochrysene is red shifted and intensified relative to water. Photobleaching occurs in H2O but not in ethanol or gamma-cyclodextrin solution. The change in dipole moment between the ground and excited states for the nitrochrysene is 12.9 D, similar to our previous measurements for related nitrostilbenes. The compound displays red-shifted emission in triethylamine, perhaps due to an excited state hydrogen-bonded complex. The absorption and emission properties of the corresponding nitrophenolate were also studied. The nitrophenolate exhibits reverse solvatochromism in its absorption spectra. In conclusion, the high sensitivity of the emission energy and quantum yield of the title compound make it of potential utility as a fluorescent probe.

Change in the oestrogen receptor status of breast cancer with age--comparison of two types of assay

The oestrogen receptor (ER) is considered to be an essential component of the mechanism of response of a breast tumour to endocrine therapy, but ER measurements have proved to have only modest predictive value. In the present study, we have examined ER status by both immunocytochemical assay (ER-ICA) on a fine needle aspirate and by radioligand-binding assay (DCC) on an excised portion of tumour. There was a correlation between the ER level detected by the two assays (Spearman's r = 0.77 for DCC versus ER-ICA staining intensity, r = 0.70 for DCC versus ER-ICA percentage of cells stained, P < 0.0001, n = 137 in each case). Each assay showed an increasing proportion of ER+ve results with increasing patient age. In the case of ER+ve tissues only, while ER concentration by DCC assay increased steadily with age (r = 0.39, P < 0.0001, n = 108), the ER-ICA assay revealed that, staining intensity increased with age (r = 0.26, P = 0.001, n = 149) but the percentage of cells stained did not (r = 0.08, P = NS, n = 149). It is concluded that increasing endocrine responsiveness with advancing age could reflect the increasing proportion of ER+ve tumours with increased levels of ER per cell (as indicated by staining intensity) rather than increasing proportion of ER+ve cells.

The prognosis of breast cancer patients in relation to the oestrogen receptor status of both primary disease and involved nodes

Nodal involvement is accepted as the best single marker of prognosis in breast cancer. However, there is little information on the sub-division of node-positive patients according to the oestrogen receptor status of the nodal tissue. We have previously reported (Eur. J. Ca. 1987, 23, 31) that, in almost all cases, involved nodes are only oestrogen receptor positive (ER+) in patients whose primary tumours are uniformly ER+. This paper presents clinical follow-up on a larger group of patients with node positive breast cancer. For each patient, both soluble and nuclear receptor concentrations were determined in three separate parts of the primary tumour and in at least one involved node (we have previously defined tumours which contained ER in all six fractions of the primary as HS++, those lacking receptor in some fractions as HS+- and wholly receptor negative tumours as HS--). Median follow-up time was 71.5 months. As expected, patients whose tumours were HS++ had a significant (P less than 0.008) survival advantage. More importantly, patients with ER in both the soluble and nuclear fractions of their involved nodes survived significantly (P less than 0.003) longer than those with ER- nodes. Thus, full oestrogen receptor status of involved nodes will give sufficient prognostic information when adequate primary tissue is not available.

Densitometric and morphometric study of immunocytochemical estrogen receptors detection in breast carcinomas

Immunohistochemical quantitative evaluation of estrogen receptors (ER) detected in tissue sections from 30 breast tumors by monoclonal antibody was performed using a densitometric method. In particular, ER concentration was calculated by nuclear mean optical density (nMOD), while heterogeneity in ER content was calculated by the coefficient of variation (CV) of the nuclear optical density histogram. Tumors which showed more than 60% of positive cells had a mean value of ER-nMOD of 0.116 +/- 0.002 a.u. and of ER-CV of 33.74 +/- 0.68. Tumors which showed 30% to 60% of positive cells had a mean value of ER-nMOD of 0.082 +/- 0.006 a.u. (arbitrary units) and of ER-CV of 36.25 +/- 3.44. Tumors showing less than 30% of positive cells had ER-nMOD of 0.052 +/- 0.009 a.u. and ER-CV of 48.49 +/- 5.61. These results indicate that the greater the concentration the lower the ER heterogeneity within the tumor sample. No significant differences between ER-ICA results, nuclear size and form factors were found.

Stereoisomeric [1,2-bis(3-hydroxyphenyl)ethylenediamine]platinum(II) complexes, Part III: Evaluation of the mammary tumor inhibiting properties

Stereoisomeric [1,2-bis(3-hydroxyphenyl)ethylenediamine]platinum(II) complexes produce a strong configuration-dependent inhibition of the hormone sensitive MXT-mammary carcinoma of the mouse. Besides an interference in the DNA synthesis in analogy to cisplatin an estrogen level lowering effect is supposed to be the mode of action. The new complexes show also a significant activity on the hormone-independent MXT-mammary carcinoma of the mouse.

Interaction between hormone-dependent and hormone-independent human breast cancer cells

We developed two different models based on in vitro co-culture of hormone-dependent and hormone-independent cell lines to simulate the cell population heterogeneity of human breast cancer tumours. Oestrogen-dependent (MCF-7, ZR 75.1) and oestrogen-independent cell lines (MDAMB-231 BT-20) were grown under serum-free conditions. Co-culture of hormone-dependent and hormone-independent cell lines resulted in an increased cell yield compared to single cell cultures carried out at the same seeding ratios. Such an increase was not affected by addition of oestradiol and single growth factors (EGF, bFGF and IGF-I). These results allow us to conclude that in a heterogeneous cell population like human breast tumours, interaction between hormone-dependent and hormone-independent cell lines may result in a complex regulation of cell growth.

Endocrine treatment for breast cancers: biological rationale and current progress

Endocrine therapy is a major treatment modality for the systemic management of breast cancer. In comparison with alternatives such as chemotherapy, hormone manipulations have the advantage of lower toxicity but suffer from the disadvantages of producing responses in only 30-40% of patients with metastatic disease and seldom being curative. Nevertheless in recent years there have been significant advances in the endocrine treatment of breast cancer which have stemmed from a better understanding of the sources from which breast tumours may be supplied with hormones, the mechanism by which hormones regulate tumour proliferation and the more accurate identification of hormone sensitive tumours. As a result agents such as antioestrogens, aromatase inhibitors. LHRH agonists have largely superseded surgical and radiological ablation of endocrine organs. The major reduction in morbidity associated with these medical regimes means that they are much more acceptable to patients and may be used as adjuvants to local treatment of the breast in patients with "earlier" stages of the disease. At the same time patients can now be offered rational treatment selected on the basis of tumour biology rather than on more empirical criteria. The aims of this review are to provide details of the research which has led to this progress in endocrine treatment of breast cancer and to put into perspective the prospects for further advances.

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.

Correlation between laminin and type IV collagen distribution in breast carcinomas, and estrogen receptors expression, lymph node and vascular involvement

The laminin (Lam) and type IV collagen (Coll IV) and estrogen receptor (ER) immunodetections were assessed in a large series of 400 human breast carcinomas. In all the cases the patient's age, the tumor size, the histological type and grade, the presence or the absence of axillary lymph node metastasis and of vascular invasion in tumor borders, and ER tumor content were recorded. Monoclonal anti-Lam, anti-Coll IV were applied with the avidin-biotin-peroxidase complex and monoclonal anti ER with peroxidase anti-peroxidase complex, on frozen sections. A computerized system of image analysis referred to as SAMBA (TITN) with specific software for tissue sections analysis permitted a multiparametric quantitative analysis of immunostained surfaces. With this system, in each tumor, the cellularity, the percentage of Lam, Coll IV and receptor positive surfaces versus the total cell surface and versus the epithelial (keratin positive) surface, the integrated optical density IOD histograms were obtained and correlated to morphometrical and standard histological data. From this study, it was shown that: (1) Lam and Coll IV immunostained epithelial basement membranes in carcinomas were correlated to the presence of estrogen and progesterone receptor antigenic sites within the tumors, with a significant decrease of the positive staining in ER-ICA negative tumors in comparison to ER-ICA/PR-ICA positive tumors. (2) The combined densitometric and morphometric evaluation demonstrated a decrease of Lam and Coll IV immunostaining in malignant tumors, correlated to (i) the presence of peritumorous vascular invasion and (ii) keratin positive cells in bone marrow (iii) axillary lymph node involvement. It is concluded that the variations in Lam and Coll IV antigens distribution may be relevant indicators of tumor metastatic potential in breast carcinomas and that computerized image analysis enables the standardization of the evaluation antigens distribution.

The significance of hormone receptors to predict the endocrine responsiveness of human breast cancer

The paper reviews clinical data on the correlation between the response of human breast cancer to endocrine therapy and the tumour cell content of receptors of e.g. oestrogen (OeR), progesterone (PgR), androgens (AR) and the epidermal growth factor (EGFR). In advanced disease there is a well established correlation between OeR content and the rate of objective response to all types of endocrine therapy. However, if selection of first-line salvage therapy based on OeR status will result in prolonged survival or improved quality of life remains controversial. Assays of PgR, AR, and EGFR--in addition to OeR--increase the predictive ability but no study has been able to define an entirely unresponsive subgroup of patients on the basis of receptor status. In the adjuvant setting conflicting relationships have been reported. Some authors have found a benefit with tamoxifen also among OeR negative patients whereas others have concluded that adjuvant tamoxifen is ineffective in such patients. Prospective randomized trials are warranted to further assess the predictive value of hormone receptors, particularly in view of the increased frequency of thrombotic events and endometrial cancer associated with long-term adjuvant tamoxifen.

Progesterone receptor determination in human breast tumors by immunocytochemical and biochemical techniques

Progesterone receptors were determined on frozen sections from 74 primary human breast tumors by an immunocytochemical assay using an indirect avidin-biotin peroxidase method. In the same tumors, cytosol estrogen (ERc) and progesterone receptors (PgRc) were determined by ligand binding assay, and nuclear estrogen (ERn) and progesterone receptors (PgRn) were determined by an immunoassay. Immunocytochemical staining was seen in 36% of tumors. It was predominantly nuclear and there was extensive cell to cell heterogeneity. When the immunocytochemical results were compared to PgRc the agreement rate was 63%, but it was 77% when compared to PgRn. About one third (38%) of PgRc positive tumors were immunocytochemically defined as negative. Thus a significant discordance exists between this immunocytochemical assay for PgR and both the conventional radioligand assay (used for PgRc) and the relatively new enzyme immunoassay (used for PgRn). However discordance rates were critically influenced by the arbitrary cutoff levels that were used to define receptor positivity in the biochemical assays. Our studies support the addition to, rather than the substitution of, immunocytochemical methods, to the conventional biochemical assays for PgR, until long-term follow-up studies of patients with PgRn and immunocytochemical PgR determinations become available.

Correlation of an Estrogen Receptor-related Phosphoprotein with Histopathological Features in Breast Cancer

A series of 65 cases of different histological types of breast carcinoma was investigated for the immunohistochemical location of the estrogen receptor-related, 29 kD phosphoprotein using the ER-D5 monoclonal antibody.

The ER-D5 response is heterogeneous in relation to some therapeutic limitations and is correlated with histopathological features of the tumors and survival. The main parameters for evaluation of breast cancers are reviewed, both those that are statistically correlated and those that are not apparently always correlated but are known to have considerable biological meaning, such as the ER-status of tumors.

Immunocytochemical assays in human endometrial carcinomas: a multiparametric computerized analysis and comparison with nonmalignant changes

Immunocytochemical assay (ICAs) were performed on frozen sections from human endometrial samples (n = 89) including normal endometrium, decidua, hyperplasia with and without atypia, and carcinomas. Monoclonal antiestrogen receptor (ER), anti-laminin (Lam), anti-type IV collagen (Coll IV), and anti-Ki67 were applied with avidin-biotin-peroxidase complex or peroxidase-antiperoxidase complex. The results of the ICAs were evaluated through a computerized system of image analysis referred to as SAMBA. It was shown that this system provided for an accurate reliable and reproducible analysis of ICAs in tissue sections. It is concluded that this multiparametric and standardized method of analysis of ICAs can further be applied in correlations with clinical and biochemical data.

Estrogen receptor immunocytochemical assay on cytologic material from primary and metastatic breast cancer

The determination of estrogen receptor (ER) status in primary and metastatic breast tumours has been facilitated by the recent advent of monoclonal antibodies to ER. The aim of this study was to determine the feasibility of estrogen receptor immunocytochemical assay (ER-ICA) applied to cytologic specimens from primary and metastatic breast tumours. One hundred and sixty specimens from 133 patients were evaluated by cytologic ER-ICA. Comparison with histologic ER-ICA was available for 28 of the specimens and with cytosol assay for 27 specimens. Some 101 of the 160 samples were breast lesions of which 87 had a definitive diagnosis of breast carcinoma. Of these, 68% were considered positive for ER. Metastatic breast cancers comprised 59 of the 160 specimens of which 37% were found to be positive for ER. The predominant staining intensity (SI) of the nuclei of the tumour cells added to the percentage of cells (PC) stained gave an estrogen receptor score (ERS) in both cytologic and histologic specimens. A positive threshold was determined for an ERS greater than 2, equivalent to ER levels greater than 10 fmol/mg of protein. We observed very good correlation between cytologic ERS and the corresponding cytosol assay values (r = 0.74; p less than 0.001; n = 27). The sensitivity was 95% and the specificity 88%. Correlation with histologic ER-ICA was also very high (r = 0.83; p less than 0.001; n = 28). We assessed the role of video image analysis (VIA) and did not find any additional advantages in evaluating cytologic ER-ICA.(ABSTRACT TRUNCATED AT 250 WORDS)

Do multiple oestrogen receptor assays give significant additional information for the management of breast cancer?

In 101 breast cancer patients, measurement of oestrogen receptor status in multiple biopsies across a tumour reveals a highly significant difference in the proportion of patients remaining either disease-free (P less than 0.04) or alive (P less than 0.005), when those with uniformly receptor positive (++) primary tumours are matched with clinically comparable patients whose tumours were homogeneously receptor negative (--). Mean follow-up time was 85 months. The prognostic value of this discriminant is particularly striking in the 53 patients with involved nodes at presentation. Of these, 13 were (++) and seven remain alive of whom six are disease-free, whereas 24 of the 29 (--) patients are dead. These results further suggest that receptor assay on a single homogenate gives less clinical information than do assays on multiple biopsies across the tumour. For patients with involved nodes, clinical management may best be decided after determination of 'macroheterogeneity'.

Immunodetection in fine-needle aspirates and multiparametric (SAMBA) image analysis. Receptors (monoclonal antiestrogen and antiprogesterone) and growth fraction (monoclonal Ki67) evaluation in breast carcinomas

Immunocytochemical assays (ICA) using monoclonal antiestrogen receptors (ER ICA), antiprogesterone receptors (PR ICA), and monoclonal antibody Ki67 (Ki67 ICA) were performed in 127 breast carcinomas. The immunostaining procedures were applied on frozen tissue sections, tumour imprints, and fine-needle aspirates in order to compare the variations in the distribution of the antigens detected in the three different types of preparations. Positive reactions detected with peroxidase-antiperoxidase and avidinbiotin-peroxidase, and alkaline phosphatase-antialkaline phosphatase complexes were evaluated through a computerized system of image analysis referred to as SAMBA 200 (SAMBA TITN, Grenoble, France). Application programs specifically developed for the analysis of tissue sections and of cytologic preparations were applied. This system allowed a multiparametric, accurate, reliable, reproducible and automatized evaluation of the heterogeneity of the antigenic sites in tumors. For each markers positive cell surface (PS), and integrated and mean optical densities (IOD, MOD) and IOD histograms were compared. It was shown that (1) there was no significant variation in optical densities in cell imprints and aspirates whereas PS significantly (P less than 0.01) differed in both preparations; (2) there were significant differences of the optical densities between tissue sections and cytological preparations, either imprints or aspirates, likely due to randomly cut nuclei in tissue sections; and (3) there was a significant difference between the PS of tissue sections and aspirates but no significant difference between tissue sections and imprints. It is concluded that fine-needle aspiration constitutes a convenient method for cell sampling, reliable for the diagnosis of malignancies. However, it may not reflect the heterogeneity of cell subpopulations in tissue.

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.

An evaluation of potentially suitable fixatives for immunoperoxidase staining of estrogen receptors in imprints and frozen sections of breast carcinoma

The estrogen receptor (ER) content of breast carcinoma is generally accepted as valuable in predicting clinical outcome and tumour response to hormonal manipulation. We applied a new immunocytochemical assay for estrogen receptors (Abbott ERICA Monoclonal) to 20 breast tumours, and examined the efficacy of 16 fixation procedures before immunoperoxidase staining of frozen sections and imprint preparations. Our findings indicate that the fixatives of choice are periodatelysine-paraformaldehyde at 22 degrees C, or 10% formalin followed by acetone at -10 degrees C. These fixation procedures are simpler, less time-consuming, and provide superior staining, tumour cytomorphology and higher ER values than the 3-reagent sequence recommended by Abbott Laboratories. There was a significant correlation between the ER scores in the frozen sections and the imprints. Positive ER cytosol results correlated with the staining index in the frozen sections, and the ER scores in the imprints. We conclude that imprints are suitable preparations for ER analysis by the immunoperoxidase technique, particularly for small tumour specimens.

Multiple microsample analysis of intratumor estrogen receptor distribution in breast cancers by a combined biochemical/immunohistochemical method

A multiple microsample analysis of estrogen receptors (ER) was performed on 81 samples obtained from 21 human breast cancers using a biochemical (BC) and immunohistochemical (IHC) method. Qualitative agreement occurred in 96% of the cases. Using both the percentage of cells staining specifically for ER as well as the intensity of staining (Histoscore) a semiquantitative correlation between the two analyses was obtained. Large variations in cellularity and the percentage of cells that stained specifically for ER existed within individual tumors. In most cases the variation in intensity of staining was minimal. Both the level and distribution of ER in different areas of individual tumors were calculated using a correction for differences in cellularity amongst samples. Heterogeneity in ER level as well as distribution was found in some tumors. In addition, a "checkerboard" type of staining with intermixed ER positive and ER negative cells was observed. This combined BC/IHC method may provide specific information about intratumor ER heterogeneity not available from either method alone.

Determination of steroid hormone-dependency of tumours utilizing tissue sections. Survey of histochemical techniques and their application in surgical pathology

The growth of neoplasms originating from steroid hormone target tissues may be hormone-dependent. It has been clearly demonstrated that the oestrogen and/or progestagen receptor status predicts the response to endocrine treatment and the prognosis of breast cancer. However steroid receptor determination in tumour cytosols has several limitations, which can partly be resolved by (immuno) histochemical detection of steroid hormone-responsive tumour cells. A variety of histochemical techniques including autoradiography of tritiated steroids, immunohistochemistry with antibodies to steroid hormones, histochemistry with fluorescent ligands of low molecular weight and fluorochrome- or enzyme-labelled macromolecular probes are discussed. It is concluded that there is as yet no substantial evidence that these methods visualize steroid receptors or detect steroid hormone-responsiveness of tumour cells. On the other hand, immunohistochemical demonstration of oestrogen receptors with monospecific antibodies seems validated and indications have been obtained that this information is clinically relevant. Recent developments suggest that immunocytochemistry of receptors and specific hormone-induced proteins, flow cytometric analysis and probably hybridocytochemistry in the future will help to improve management of steroid hormone-dependent tumours.

Histochemical estrogen binding. An independent predictor of recurrence and survival in stage II breast cancer

Cox's proportional hazards regression model was used to analyze the prognostic significance of multiple variables affecting recurrence and survival in patients with Stage II breast cancer. Among the variables were biochemical estrogen (ER) and progesterone receptor (PgR) values and results of a histochemical estrogen-binding assay using a fluoresceinated bovine serum albumin-estradiol conjugate where carrier and label were bound at position 17. In 190 cases ER and PgR were not found to be significantly associated with either disease recurrence or patient survival. On the other hand, patients with tumors that were demonstrably "rich" in estradiol ligand conjugate binding by histochemistry experienced both a longer disease-free interval (P less than 0.03) and survival (P less than 0.02) than did patients whose tumors were "poor" in conjugate binding or showed a heterogeneous population of positively and negatively stained cells. A patient with a tumor rich in estrogen binding was five times more likely to survive than a patient with a neoplasm that was poor in estrogen binding by histochemistry. These results indicate that the histochemical technique used provides new and independent parameters for determination of prognosis in Stage II breast cancer.

Comparative histological, histochemical, immunohistochemical and biochemical studies on oestrogen receptors, lectin receptors, and Barr bodies in human breast cancer

The present study performed on a total of 567 cases of human female breast cancer compares the results of the biochemical assay (dextran-coated charcoal assay = DCC) for oestrogen receptor (ER) with those of several morphological methods developed for the detection of the ER or for the prediction of prognosis by use of other systems (FSA = fluorescent ligand binding assay, ER-ICA = monoclonal antibody assay for ER, LRA = lectin receptor assay using peanut agglutinin, and Barr body estimation). Whereas no correlation at all was observed among the results of the DCC and those of the FSA and Barr body estimation, the ER-ICA and the LRA showed an unanimous tendency towards higher values of ER with increasing intensity of the staining product. The results of the ER-ICA may be expressed by an immuno-reactive score (IRS) calculated from the staining intensity (SI) and the percentage of positive cells (PP). The morphological methods are evaluated with special regard to their correlation with the DCC, their theoretical basis, and their practical application. In summary, the ER-ICA appears to be the sole method directly visualizing the ER protein and--in contrast to the DCC--is therefore completely independent of the content of endogenous or exogenous oestrogens in the tumor tissue. The LRA provides valuable additional information concerning tumour differentiation and possible response to endocrine therapy, whereas the FSA and Barr body estimation should be considered as obsolete and should therefore be abandoned.