A simple method for the determination of oestrogen receptor concentrations in breast tumours and other tissues

Estrogen and Progesterone Receptors in Breast Carcinoma and in Nonmalignant Breast Tissue

Since 1983 we have studied the relationship, in the same patient, between receptor status in breast carcinoma and in nonmalignant breast tissue. Fifty patients have been evaluated to date. The total unoccupied cytosol estrogen and progesterone receptors were determined by a dextran-coated charcoal method. In nonmalignant breast tissue we found a measurable receptor concentration above the sensitivity of the method in 62 % of cases for estrogen receptors and in 44 % of cases for progesterone receptors. No relationships were found between the receptor level of each tumor and that of the corresponding benign tissue. The data suggest that the levels of the receptors in the tumor and in the nonmalignant tissue are totally independent.

Preoperative Assessment and Staging of Breast Cancer: Preliminary Communication

A prospective study has been carried out in 172 women to determine the sensitivity of methods to detect occult metastatic disease in the skeleton and liver. With the exception of bone scintiscans, the results of these tests bore little relationship to recurrence rates. On the other hand, knowledge of the histopathology of the lower axillary (pectoral) lymph nodes is of value in this respect.

A follow-up study is also reported which confirms the importance of accurate measurements of the primary tumour clinical node status and oestrogen receptor contact of the tumour in defining prognostic groups. Elastosis (estimated in 165 tumours) did not prove to be a useful prognostic index.

Human tissue in systems medicine

Histopathology, the examination of an architecturally artefactual, two-dimensional and static image remains a potent tool allowing diagnosis and empirical expectation of prognosis. Considerable optimism exists that the advent of molecular genetic testing and other biomarker strategies will improve or even replace this ancient technology. A number of biomarkers already add considerable value for prediction of whether a treatment will work. In this short review we argue that a systems medicine approach to pathology will not seek to replace traditional pathology, but rather augment it. Systems approaches need to incorporate quantitative morphological, protein, mRNA and DNA data. A significant challenge for clinical implementation of systems pathology is how to optimize information available from tissue, which is frequently sub-optimal in quality and amount, and yet generate useful predictive models that work. The transition of histopathology to systems pathophysiology and the use of multiscale data sets usher in a new era in diagnosis, prognosis and prediction based on the analysis of human tissue.

Behaviour of estrogen receptor, histological correlation, and clinical outcome in patients with benign breast disorders

OBJECTIVE

To estimate the value of estrogen receptor (ER) in benign breast diseases and to find out if the response of benign breast diseases to danazol depends on the ER status of the tissue.

DESIGN

Prospective study.

SETTING

University hospital, India.

MATERIAL

Samples of tissue from benign breast lesions, 40 fibrocystic disease and 10 fibroadenomas.

INTERVENTIONS

Enzyme immunoassay for the presence of cytosolic ER.

MAIN OUTCOME MEASURES

ER concentrations, and correlation with effect of treatment with danazol.

RESULTS

Fibrocystic disease and fibroadenomas showed 30% and 40% ER positivity, respectively. The mean (SD) ER concentration was significantly higher in premenopausal than postmenopausal patients 14.75 (3.79) fmol/mgm compared with 6.2 (1.59) fmol/mg (p < 0.05). All ten patients with mastalgia who had ER-positive lesions (n = 26) responded to danazol, compared with 6 of 16 patients who had ER-negative lesions (p < 0.05). Lesions with diffuse fibrosis (n = 14) and five with lymphocytic infiltration on histology were all ER-negative.

CONCLUSION

The patients with ER positive breast disease responded better to danazol than patients with ER negative breast disease.

Oestrogen receptor: a stable phenotype in breast cancer

Oestrogen receptor (ER) expression in breast cancer is regarded as a phenotype that may change during the natural history of the disease or during endocrine therapy. It has been suggested that in up to 70% of tumours that show acquired resistance the mechanism may be changed in ER status from positive to negative. This paper proposes an alternative hypothesis that ER expression in a stable phenotype in breast cancer. The paper reviews the literature on ER expression during the natural history of breast cancer in patients and also presents data on the effect of endocrine therapy on ER expression. If the alternative hypothesis is true it has important implications for treatment from chemoprevention to acquired endocrine resistance in advanced disease. Equally, if the hypothesis is true, attempts to develop laboratory models of endocrine resistance where ER-positive tumours become ER negative need to be re-evaluated.

The regulation of growth and protein expression by estrogen in vitro: a study of 8 human ovarian carcinoma cell lines

The effects of 17 beta-estradiol (E2) on the growth and the levels of estrogen receptor (ER), progesterone receptor (PR) and pS2 protein were examined in a range of 8 ovarian carcinoma cell lines. E2 stimulated growth of the 3 cell lines with an ER content of 80-220 fmol/mg protein but not the 5 cell lines with ER concentrations less than 20 fmol/mg protein. After exposure to E2, ER concentration in 2 of the 3 responsive cell lines was decreased relative to untreated cells and in 2 lines, progesterone receptors were increased. No change in steroid receptor levels was observed in cell lines with low or negligible levels of receptors. The pS2 protein was not induced by E2 in the 5 ovarian carcinoma cell lines examined. These results indicate that E2 can stimulate the growth of some ER-positive ovarian carcinoma cells and that these effects may be associated with changes in the cellular levels of steroid hormone receptors.

Expression of transforming growth factor beta mRNA isoforms in human breast cancer

Using an RNAse protection assay, expression of messenger RNA for isoforms of TGF-beta was determined in a series of breast cancers. Of 50 tumours, 45 (90%) expressed TGF-beta 1 mRNA, 39 (78%) expressed TGF-beta 2, and 47 (94%) expressed TGF-beta 3. Patterns of expression varied between different tumours: 37 (74%) cancers expressed all three TGF-beta isoforms, ten (20%) expressed only two isoforms and two expressed TGF-beta 1 alone. One sample showed no evidence of TGF-beta mRNA expression. Although most breast cancers expressed mRNA for at least one isoform of TGF-beta, there were differences in patterns of mRNA expression between individual tumours. The relatively small number of tumours examined precluded detailed analysis between expression and other clinical parameters, but a significant association was identified between one aspect of isoform expression and lymph node status, in that the majority of tumours expressing all three isoforms were associated with lymph node involvement, whereas tumours without one or more isoform were usually lymph node negative (P = 0.025 by Fisher's exact test).

Contrasting effects of 17 beta-estradiol on the growth of human ovarian carcinoma cells in vitro and in vivo

A human ovarian adenocarcinoma cell line (PE04) has been established as a xenograft in nude mice. In vitro, this cell line is estrogen receptor (ER)-positive and its growth is stimulated by 17 beta-estradiol at concentrations between 10(-12) and 10(-6) M. When xenografted, PE04 cells remain ER-positive and also possess progesterone receptors (PR); treatment with 17 beta-estradiol reduces the concentration of ER and increases levels of PR. Growth of the xenograft is reduced in ovariectomized animals while implantation of estrogen pellets also results in growth inhibition. Similar treatment with estrogen does not inhibit the ER-negative HOX 60 ovarian xenograft, and stimulates growth of the ER-positive ZR-75-I breast carcinoma xenograft. Serum measurements of 17 beta-estradiol confirm that ovariectomy reduces the level of 17 beta-estradiol while implantation of estrogen pellets results in raised levels of the hormone. Tamoxifen inhibits growth of the PE04 xenograft but not that of the HOX 60 xenograft, consistent with ER status. These results indicate that ER-positive PE04 ovarian cancer cells are sensitive to 17 beta-estradiol in vivo but that the response may be of a different type from the in vitro response. This lends further support to the concept that ovarian cancer may be hormone-sensitive and potentially responsive to endocrine therapy.

Tumour cyclic AMP binding proteins: an independent prognostic factor for disease recurrence and survival in breast cancer

In two separate cohorts of breast cancer patients presenting without evidence of distant metastatic disease, high levels of tumour cyclic AMP binding proteins (> 8 pmol/mg cytosol protein) have been shown to be associated with poor prognosis in terms of both disease recurrence and overall survival. This association is independent of known established prognostic factors and allows the identification of a small subgroup of patients whose outlook warrants the implementation of aggressive systemic therapy.

The differing predictive values of oestrogen receptor assays for large breast cancers

Thirty elderly patients with T3 or T4 breast cancer underwent a wedge biopsy for radioligand-binding assay (RLA) of oestrogen receptor (ER) activity. A second, separate group of 21 elderly patients with T3 and T4 breast cancers underwent fine needle aspiration biopsy (FNA) for immunocytochemical assay of ER (ER-ICA). All the women received tamoxifen as primary treatment and response was assessed by UICC criteria. Tumour ER concentration by RLA was correlated with both response (Spearman's R = + 0.52) and time to progression (R = + 0.76). Nine patients with receptor-rich tumours (> 100 fmol/mg protein) failed to show a response. However, the percentage of cells staining for ER by ER-ICA assay was much more strongly related to the likelihood of response (R = + 0.89); no patient with < 20% cells staining responded. Wedge biopsy and the biochemical determination of ER activity is of limited value in predicting the likely response to tamoxifen; ER-ICA assays on such tumours may be more informative.

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.

Primary systemic therapy for operable breast cancer

Eighty-eight patients presenting with operable breast cancer of 4 cm or greater in diameter (T2, T3, N0, N1, M0) have received primary systemic therapy. Response was assessed following 12 weeks of systemic therapy by linear regression analysis of changes in tumour volume. Definitive locoregional surgery (mastectomy n = 82, wide local excision n = 6) was performed on completion of systemic therapy (3-6 months). Response was observed in 24 (39%) of the 61 patients who received endocrine therapy; all 24 had tumours with an oestrogen receptor (ER) concentration of greater than or equal to 20 fmol mb-1 cytosol protein. Cytotoxic therapy was reserved for patients with tumours of ER concentration less than 20 fmol mg-1 cytosol protein (n = 27) or when endocrine therapy had failed (n = 20). Response was observed in 34 patients (72%). The overall survival rate at 3 years was 86%, with 81% remaining free from local relapse. We propose that the treatment policy outlined in this paper should now be tested against orthodox management by controlled randomised trial.

Epidermal growth factor receptors in intracranial and breast tumours: their clinical significance

A method to determine the binding of epidermal growth factor (EGF) to the particulate fraction of the cell has been established and evaluated using rat liver, human placenta, and tumours of human breast and brain. Little EGF receptor (EGFR) activity was detected in normal or benign tumour tissues except for meningioma (positive in 95% samples), but EGFR were present in 43% of 131 breast tumours and 75% of 55 primary cerebral tumours. Despite the strong inverse correlation between EGFR activity and oestrogen receptors in breast tumours and a tendency for high levels of EGFR activity to be associated with glioblastoma multiforme, analysis showed that EGFR was of little prognostic significance in patients with tumours of either breast or brain.

The H-ras oncogene product p21 and prognosis in human breast cancer

The protein product of the H-ras oncogene, p21, has been measured semiquantitatively in solubilized particulate fractions of 160 primary tumours from patients presenting without evidence of distant metastatic breast cancer. Levels of p21 have then been related to factors of established prognostic significance, and to clinical outcome after primary treatment in terms of disease-free interval and survival times. p21 was detected by Western blotting in all tumour fractions, but amounts varied markedly between different tumours. There was no significant relationship between levels of p21 and the menopausal status of the patient, tumour oestrogen receptors, grade, and clinical stage. However, there was a significant trend for tumours to be associated with lymph node involvement as p21 was increasingly expressed. Elevated levels of p21 were also significantly related to early disease recurrence and death from cancer. Multivariate stepwise analysis showed that both p21 and lymph node status were independent statistically significant factors for disease recurrence and survival, and that no other parameter was significant for clinical outcome after adjustment for p21 and lymph node status. These results indicate that tumour levels of p21 are an important prognostic variable in patients with early breast cancer.

Relationship between tumour aromatase activity, tumour characteristics and response to therapy

Aromatase activity has been measured in human breast cancers by incubating tumour minces with [7 alpha-3H]testosterone and characterizing purified oestradiol (E2) fractions by chemical derivative formation. Of 247 primary tumours, 178 showed evidence of oestrogen biosynthesis, levels varying between 0.5 and 12.5 fmol E2 produced/h/g tissue. These values were quantitatively small but at least comparable with those in other peripheral tissues. There was no correlation between presence or level of aromatase activity and the histopathology of the tumours although oestrogen biosynthesis was more likely to be present in more cellular tumours. Aromatase activity was also unrelated to age, menopausal status, lymph node status and T stage of the patient from which the tumour was derived. In a subgroup of patients presenting without clinical evidence of distant metastatic disease, no significant relation was detected between tumour aromatase and disease-free interval, but tumours without aromatase activity were associated with increased survival at 36 months after primary treatment. A statistically significant correlation was also detected between the presence of tumour aromatase and oestrogen receptors. Furthermore, in small subgroups of patients with "advanced" breast cancer tumour aromatase was related to response to aminoglutethimide but not tamoxifen therapy. Whilst these results do not conclusively define a role for local synthesis of oestrogen in the progression of breast cancer, this possibility still exists and further studies on tumour aromatase are warranted.

Oestrogen receptor expression and the effects of oestrogen and tamoxifen on the growth of human ovarian carcinoma cell lines

To assess the role of oestrogen regulation in the growth of ovarian cancer, we examined the effects of an oestrogen, 17 beta-oestradiol, and an anti-oestrogen, tamoxifen, on oestrogen receptor (ER) -positive and -negative human ovarian carcinoma cell lines. As measured by a dextran-coated charcoal adsorption assay, cell lines PEO1, PEO4 and PEO6 possessed moderate concentrations of ER (96-132 fmol mg-1 protein), PEA1 and PEA2 had low values (12-23 fmol mg-1 protein) and PEO14, TO14, PEO23 and PEO16 were ER-negative. Addition of 17 beta-oestradiol (10 nM or 0.1 nM) to the ER +ve cell line, PEO4, increased the growth rate. This oestrogen stimulation could be blocked by 1 microM tamoxifen. In contrast, the growth rate of the ER -ve cell line PEO14 was unaffected by the addition of 17 beta-oestradiol or tamoxifen. Concentrations of tamoxifen in excess of 8 microM were required to produce complete cytostasis in all lines. This concentration of tamoxifen over 72 hours also inhibited 50% colony formation when cells were plated on plastic. These data indicate that some ovarian carcinoma cell lines contain ER and their growth can be sensitive to oestrogen and anti-oestrogen modulation.

Does the oestrogen receptor concentration of a breast cancer change during systemic therapy?

The effect of systemic therapy on tumour oestrogen receptor (ER) concentration has been studied in 88 patients with large, operable, primary tumours (total 89) of the breast. In 26 patients, tumour was not available for study on one occasion (usually post-treatment). Forty-five patients were treated initially by endocrine therapy but, of these, 13 who had failed to respond went on to receive chemotherapy also. Seventeen patients with low concentrations of ER (less than 20 fmol mg-1 protein) were treated directly by chemotherapy. Patients underwent an incisional biopsy for confirmation of diagnosis and determination of pre-treatment ER by radioligand binding assay, followed by systemic therapy for 3 months (or 6 months for both endocrine and cytotoxic therapies). Response was assessed clinically and mammographically before mastectomy. ER concentration was then determined in the post-treatment tumour specimen. No significant change in ER concentration was seen in any treatment group except when the patients had received tamoxifen; there, receptor concentration fell to very low levels, presumably due to interference with the assay. There was no relationship between tumour response to systemic treatment and change in ER concentration. It is concluded that changes in ER concentration are unlikely to play a major role in the early response of breast tumours to systemic therapy.

Cyclic AMP binding proteins and prognosis in breast cancer

Cyclic AMP binding proteins were measured in the primary tumour from 100 patients with non-disseminated breast cancer selected on the basis that sufficient tumour material was available for analysis. These measurements have been related to factors of established prognostic value and to the patients' disease-free interval and survival. There was a wide variation in amounts of binding proteins in different tumours. Values were significantly higher (P less than 0.05) in oestrogen receptor-negative tumours but no statistically significant correlations were apparent between levels and tumour grade or whether the patients had lymph node metastasis or adjuvant treatment. However, levels were significantly higher in patients whose disease recurred within 3 years of primary treatment as compared with those who remained disease-free. Using a retrospectively determined cut off point of 8 pmol mg-1 cytosol protein, it was shown that patients with tumour cyclic AMP binding in excess of this value had a significantly greater chance of developing recurrent disease and poorer survival rates (P less than 0.001 by Cox analysis) than those with lower levels. This remained true when other prognostic factors were taken into account in a multivariate analysis. It is suggested that the level of tumour cyclic AMP binding may be an independent prognostic factor for patients with early breast cancer.

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

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

Relationships between oestrogen receptor,epidermal growth factor receptor, ER-D5, and P24 oestrogen regulated protein in human breast cancer

Proteins regulated by or related to the oestrogen receptor (ER) may prove to be more reliable indicators of prognosis and hormone sensitivity then expression of the receptor itself. It has been shown recently that expression of epidermal growth factor receptor (EGFR) is associated with a poor prognosis in breast cancer. In a series of 60 breast cancers, we have studied relationships between ER, ER-D5 oestrogen receptor related protein, P24 oestrogen regulated protein, and EGFR using an immunohistochemical technique employing monoclonal antibodies in each case. In addition, radioligand binding assays for ER and EGFR were carried out and tumour histological grade was determined. Seventy-one per cent and forty-three per cent of tumours stained for ER-D5 and P24, respectively, but there was no relationship between staining for these and ER or EGFR status. There was a significant correlation between staining for ER and EGFR, and the respective biochemical assays. Relating ER to EGFR, very few ER-positive cases expressed EGFR, but this relationship fell short of significance. The prognostic significance of expression of the epitopes recognized by the ERD5 and P24 antibodies must await assessment of clinical outcome.

Hormone receptors in breast cancer: a conservative determination of receptors' presence in tumor tissue and ipsilateral normal mammary gland

Estrogen (ER) and progesterone (PgR) receptors were evaluated in the tumor tissue (T) and in the mammary gland far from malignancy (D) in 36 breast cancers. Results were correlated with the pathological grading of the tumor and the axillary nodal status. It is suggested that a lower cancer malignancy with negative nodes and lower values of pathological grading (G1-G2) may be associated with a high level of ER in the mammary parenchyma far from the tumor (D).

A reevaluation of an agent proposed for imaging oestrogen receptors: 17 alpha-[125I]-iodovinyl-11 beta-methoxyoestradiol-3-methyl ether ([125I]VMEME)

The metabolism of an iodinated steroid, 17 alpha-[125I]iodovinyl-11 beta-methoxyoestradiol-3-methyl ether ([125I]VMEME), previously proposed as a potential agent for imaging oestrogen receptor-containing tissues, has been studied and the conditions for synthesis and labelling redefined. It is confirmed that, although the compound does not itself have significant receptor-binding affinity, a metabolite is active. Because of its high solubility in fat and the consequential low contrast of small receptor-containing tumours, there is little prospect of successful early imaging of small axillary or internal mammary lymph node metastases from human breast cancer with this compound. Some more general implications of this finding are considered.

Prostaglandins and prognosis in human breast cancer

Prostaglandins E2 and F2 alpha (PGE2 and PGF2 alpha) were measured by gas liquid chromatography--mass spectrometry (glc-ms) in extracts of primary tumours from 78 patients with early breast cancer. These levels have been related to factors of established prognostic value and the patients disease-free interval. Although there was a wide variation in amounts of both prostaglandins extracted from different tumours, no significant relationship was observed between levels of prostaglandins and oestrogen receptors (ER), tumour size, presence of lymph node involvement and disease-free interval following primary treatment. It therefore seems unlikely that the level of these particular prostaglandins within breast carcinomas plays a fundamental role in the prognosis of the disease.

Oestradiol binding activity in rat liver tumours and in human hepatocellular carcinoma

Oestradiol binding activity was studied in normal liver tissues of rats as well as in experimentally induced liver tumours by incubating a cytosol prepared from the tissue with radioactive oestradiol. The free radioactive hormone was absorbed by a dextran-charcoal suspension, and the amount required to saturate the receptors was calculated by a Scatchard plot. Similar activity was observed in normal human liver as well as naturally occurring hepatocellular carcinoma.

Estrogen and progesterone receptors in human breast cancer. Correlation with histologic subtype and degree of differentiation

Microscopic review of 490 consecutive human breast biopsy and mastectomy specimens were correlated with estrogen and progesterone receptor content of the tissue, by subtype and degree of differentiation. Of the 4 grades of differentiation, the less differentiated Grade III and IV tumors showed significantly lower levels of estrogen and progesterone receptors in infiltrating ductal and lobular carcinoma (P less than 0.001). In contrast, patients with medullary carcinoma had the lowest tissue levels of estrogen and progesterone receptors with approximately 80% of the cases with less than 10 fmol/mg protein. Patients with mucinous carcinoma had the highest percentages of positive estrogen and progesterone receptor levels (75% and 87%, respectively). Sixty-three percent of the patients with Grade IV infiltrating ductal carcinoma were younger than 53 years of age (P less than 0.001). Patients younger than 53 years of age with Grade II and III infiltrating ductal carcinoma also had significantly lower levels of estrogen receptors, but not of progesterone receptors, than those patients older than 53 years of age (P less than 0.001). Nineteen of 20 "normal" breast tissue specimens were negative (less than 3 fmol/mg protein) for estrogen and progesterone receptors. About 50% of 17 tissue specimens from benign breast lesions (fibroadenoma, fibrocystic disease, sclerosing adenosis) showed positive estrogen (greater than 10 fmol/mg protein) or progesterone receptor values. In two patients with gynecomastia, no estrogen or progesterone receptors were detectable.

Survival in breast cancer related to tumour oestrogen receptor status and immunohistochemical staining for NCRC 11

NCRC 11 is a monoclonal antibody raised against dissociated breast cancer cells. Using this antibody, it has been shown in an earlier study that staining of a high proportion of tumour cells is strongly associated with superior survival. Many investigators have found that positive tumour oestrogen receptor (OER) status is associated with better survival in breast cancer. In the present study of 136 breast cancer patients followed up for a minimum of 30 months, tumour oestrogen receptor assays were carried out, and using the indirect immunoperoxidase technique, histological sections of paraffin embedded material were stained for NCRC 11; for the purpose of this study, tumours showing 25 per cent or less cells staining were regarded as 'negative'. Patients whose tumours were OER positive had a significantly better prognosis (logrank test P less than 0.05). Patients whose tumours were graded as negative for NCRC 11 had a poorer prognosis compared with the positive group but this did not attain significance. Our failure to demonstrate convincingly a better prognosis for the NCRC 11 positive patients may relate to the shorter duration of our study, or to different tissue fixation techniques. In this study staining for NCRC 11 was positively correlated with oestrogen receptor status (P less than 0.02).

Estimation of oestrogen and progesterone receptors in chronic rhinitis

The turbinates of 38 patients with chronic rhinitis were examined biochemically for oestrogen and progesterone receptors. Low levels of oestrogen-receptor-like activity (1-20 fmol/mg protein) were found in 50% of patients of both sexes. Progesterone receptor activity was also weak (1-16 fmol/mg protein) but was present only in 5 female patients. Immunocytochemical assay failed to demonstrate focal areas of oestrogen receptor activity. One juvenile nasopharyngeal angiofibroma was negative for both oestrogen and androgen receptors. Other possible mechanisms of hormonal action are considered.

A method for the determination of estrogen receptor concentration in calf uterus and other tissues using an aqueous two-phase system

An assay for the cytoplasmic estrogen receptor in calf, human and rat uterus has been developed. The method is based on partial separation of free and bound estradiol (E2) by means of an aqueous two-phase system containing dextran and poly(ethylene glycol), respectively, in the two phases. Low-speed supernatant from uterus homogenate is equilibrated with E2 and [3H]E2. A two-phase mixture is then added and bound E2 will partition into the lower phase while free E2 is distributed in both phases according to its partition coefficient. The amounts of bound and free E2 are calculated and the receptor concentration and association constant are obtained from a Scatchard plot. No dissociation of bound E2 in the phase system could be demonstrated at 4 degrees C. The interassay coefficient of variation for receptor concentration at 4 degrees C was 20 and 14% for calf and human uterus, respectively. The intraassay variation for receptor concentration in calf uterus determined at 4 degrees C and 23 degrees C was 7.1 and 4.1%, respectively. The influence of freezing the tissue and supernatant preparation was examined and results from supernatant preparations obtained with different centrifugations were compared. The method is simple and rapid, permitting large numbers of samples to be handled efficiently by a single technician.

Prostaglandins in human mammary cancer

Prostaglandins E2 and F2 alpha (PGE2 and PGF2 alpha) were measured by Gas Liquid Chromatography-Mass Spectrometry (GLC-MS) in extracts of 100 human mammary carcinomas. All tumours contained measurable amounts of both prostaglandins but wide variations between individual tumours were observed. Values for PGE2 ranged from 7 to 762 ng g-1 tissue with a median of 100 ng g-1 tissue. Values for PGF2 alpha ranged from 3 to 475 ng g-1 tissue (median 60 ng g-1 tissue). There was a highly significant positive correlation between amounts of the 2 prostaglandins in individual tumours. Amounts of both PGE2 and PGF2 alpha were not significantly related to the menopausal status of the patients or the presence of oestrogen and progesterone receptors.

Effects of drugs associated with hyperprolactinemia on plasma steroids and on steroid receptors and metabolism in human breast cancer

Certain commonly taken pharmaceutical preparations induce increased levels of plasma prolactin. The effects of these drugs on (a) tumor steroid receptors and metabolism, and (b) plasma hormones and hormone binding proteins have been studied in postmenopausal women with breast cancer. Two groups have been compared, 18 patients on drug treatment for at least 2 months and 15 subjects with no history of drug ingestion. Patients taking medication had significantly higher levels of plasma prolactin compared with control women. No significant difference was observed between the groups with regard to the plasma concentrations of dehydroepiandrosterone (DHA) and its sulphate (DHS), testosterone, estrone, estradiol-17 beta, sex hormone binding globulin (SHBG), and albumin. Similarly, no difference was observed between these two groups with regard to estrogen receptor (ER), progestogen receptor (PR), or androgen receptor (AR) levels in the tumors nor their ability to metabolize (7(-3)H) testosterone. It is considered that the ingestion of these drugs does not affect tumor mechanisms involving steroids.

Elastosis and primary breast cancer

One hundred sixty-five patients with primary operable breast cancer were followed for up to 60 months. Each patient had the amount of focal elastosis and the estrogen-receptor activity within the tumor determined, as well as the tumor size, axillary nodal palpability, and nodal involvement. The risks of recurrence and death were compared by constructing life tables and assessing differences in various subgroups. There was no demonstrated association between tumor elastosis and the patients' age, menstrual status, the palpability of axillary lymph nodes, or the pathological states of these nodes at mastectomy. A tendency for larger tumors to have less elastosis was noticed. A significant association between the grade of elastosis and the presence, or absence, of estrogen-receptor activity was seen. The degree of focal elastosis in the primary tumor, alone, was disappointing as a prognostic factor. A strong suggestion that estrogen-receptor activity is a better indicator of prognosis was present.

The acute effect of oestrogens on testosterone production appears not to be mediated by testicular oestrogen receptors

Scatchard binding analysis was performed to measure the cytoplasmic oestrogen receptor in the testis of rats. After treatment of rats with the antioestrogen tamoxifen no oestrogen receptor binding was found in testicular low speed supernatant between 12 and 96 h after treatment. Such tamoxifen-treated rats were used to study the acute effect of oestrogens on testosterone secretion, both in vivo and in vitro. Injection of oestradiol benzoate (50 microgram, 24 h prior to experiment) resulted in a significant depression of basal and LH-stimulated plasma testosterone levels in control rats and this effect was unchanged in tamoxifen-pretreated rats. In vitro, oestradiol-17 beta also inhibited the LH-induced rise in testosterone secretion by isolated testicular interstitial cells. This inhibition was not affected if the rats had been pretreated with tamoxifen. These results indicate that the inhibitory effects of exogenous oestrogens on testicular testosterone production are probably not mediated by the oestrogen receptor.

Cellularity and the quantitation of estrogen receptors

Fifty estrogen receptor (ER)-positive breast cancers have been studied to determine the best way of correcting for differences in cellularity when expressing ER concentration. ER concentration expressed on wet weight and tumour cytosol protein bases showed a positive correlation with tumour cellularity. In contrast, ER concentrations expressed on a DNA basis were not significantly related to cellularity. Although such a mode of correcting for differences in cellularity was imperfect, it did yield a receptor concentration which was less dependent upon tissue cellularity and which may reflect more accurately the inherent receptor status of the tumour cells.

Oestrogen receptors and primary breast cancer

Oestrogen receptor activity has been determined in the primary tumours from 243 patients with breast cancer and the subsequent clinical course of the disease has been followed for one to five years. Patients with oestrogen receptor-negative tumours had significantly shorter disease free intervals and survival times than those with receptor-positive tumours. Patients with large tumours, or with palpable axillary lymph nodes, or with histopathologically proven involvement of axillary lymph nodes also had a poorer prognosis than those with small tumours, impalpable nodes or histopathologically noninvaded nodes. The prognostic value of oestrogen receptor status was independent of these other three indices so that combination of receptor status and node status permitted definition of groups of patients with particularly good and particularly bad prognosis. The independence of these prognostic indices may relate to the possibility that whilst oestrogen receptor status is an index of the intrinsic biological behaviour of the tumour, nodal involvement and tumour size are more likely to reflect the chronological stage in the course of the disease at which the patient presents.

Oestrogen receptor concentration in primary breast cancer and axillary node metastases

The primary tumour and 1-3 invaded, axillary nodes from each of 24 patients were examined both histologically for the proportion of the specimen constituted by malignant epithelial cells ('cellularity index') and biochemically for oestrogen receptor concentration. Both malignant epithelial cell content and oestrogen receptor concentration were significantly higher in the nodal metastases than in the primary tumours, malignant cells constituting approximately half of the former tissue and three quarters of the latter. On average, receptor concentrations were 1.6 x (protein basis) to 2.3 x (wet weight basis) higher in nodes than in the primary tumours, probably due at least in part to the difference in cellularity. When, to eliminate the effect of the latter, receptor concentration in each tumour deposit was 'corrected' using the appropriate 'cellularity index', the difference in receptor concentration between primary and node was significantly diminished, but not quite eliminated. In one patient, progestogen receptor concentrations were also studied and found to be higher in the nodes than in the primary tumour. If the actual quantity of receptor is to be used for predictive/prognostic purposes, then either a different 'cut-off point' should be used for invaded nodes from that used for assessment on the primary tumour, or receptor concentrations should be corrected for differences in cellularity.

Immunofluorescent detection of hormone receptors in cutaneous melanocytic tumours

Immunofluorescent assessment of hormone receptors in melanocytic tumours is quite feasible without loss of diagnostic material, in contrast to the impracticability of quantitative biochemical assays. Using this method, oestrogen receptors were demonstrated in 4/6, and progesterone receptors in 3/5 patients with metastatic melanoma. Receptors were not found in 3 patients with primary cutaneous melanomas of the superficial spreading type. Progesterone receptors were present in the junctional component of a naevus from one healthy person.

Influence of tissue homogenization techniques on levels of estrogen and progesterone receptors measured in calf uterus and human breast tumors

We have investigated the solubilization of estrogen and progesterone receptors during homogenization of human breast tumor and calf uterus tissue. With chopped human breast tumor tissue, the maximum yield of binding proteins occurred after mechanical homogenization at 4 degrees C with a polytron PT-10 instrument running at setting 5 for 10-15 seconds. With frozen or lyophilised tissue powders the maximum yield of binding proteins occurred after intermittent vortex mixing with buffer over 60 min. at 4 degrees C. The solubilized receptor proteins were stable for at least 150 min. at 4 degrees C. Mechanical homogenization of the tissue powder suspensions resulted in rapid denaturation of the receptors. No improvement in stability was obtained by including 10 mM monothioglycerol and 10% glycerol in the homogenization buffer.

Metabolism of estrone sulphate by benign prostatic hyperplasia in vitro

Homogenates of benign prostatic hyperplastic (BPH) tissue and abdominal muscle were incubated with [3H] estrone sulphate in the presence of NADH and NADPH. The metabolites were extracted with chloroform, isolated by thin layer chromatography (TLC) and identified by addition of 14C-labelled standards followed by sequential chromatography and acetylation. Both tissues transformed the substrate into [3H] estrone and [3H] estradiol-17 beta, but BPH tissue by far exceeded the abdominal muscle in this respect. Estriol and other polar metabolites could not be detected. The specific ability of BPH tissue to convert the major peripheral estrogen estrone sulphate into the terminal biologically active estrogen estradiol-17 beta further indicates an etiological role of estrogens in the development of human BPH.

Estrogen receptor values in patients with benign breast disease

Tissue specimens from 55 female patients with benign breast disease were assayed for estrogen receptor. Twenty-one of 55 patients (38%) had tumors which contained significant amounts of estrogen receptor (greater than 10 femtomoles/mg protein). Fibroadenomas possessed estrogen receptor more frequently than fibrocystic disease or other benign breast tumors. Estrogen receptor positivity did not correlate with laterality of the tumor; location or size of the largest nodule. Patients with estrogen receptor positive tumors had a mean age of 26.9 years compared to 36.4 years for patients with estrogen receptor negative tumors (p less than 0.01). Twenty of 46 (43%) premenopausal patients had benign tumors which were estrogen receptor positive compared to zero of 8 postmenopausal patients (p less than 0.05).