Does tamoxifen change oestrogen and progesterone receptor expression in the endometrium and breast?

We studied the expression of oestrogen and progesterone receptors (ER, PR) in postmenopausal women receiving tamoxifen for breast cancer. In addition the literature addressing the question of ER and PR expression in breast tissue during treatment with tamoxifen was reviewed. We demonstrated consistent expression of ER and PR in endometria from patients receiving tamoxifen, with a trend towards a higher proportion of receptor positive specimens during tamoxifen. In breast cancer tissue, the ER content seemed to be reduced following tamoxifen treatment. After short time exposure to tamoxifen, the PR appeared to be increased, longer treatment caused the PR to go down to pretreatment levels or below.     

Mechanisms of hormone resistance in breast cancer

Summary At least half of all advanced breast cancers are positive for estrogen receptor (ER) and progesterone receptor (PR), but many nevertheless fail to respond to endocrine therapy. Studies of breast cancer cell lines and breast tumor specimens are beginning to reveal molecular heterogeneity of the receptors in subpopulations of these cells, leading to altered receptor function and sometimes to hormone resistance. Here we will review the data on molecular and cellular heterogeneity involving ER and PR, and possible underlying mechanisms of resistance to tamoxifen and progestins.     

High progesterone receptor expression correlates to the effect of adjuvant tamoxifen in premenopausal breast cancer patients.

PURPOSE: Tamoxifen has long been the drug of choice in adjuvant endocrine therapy of steroid hormone receptor-positive breast cancer, and it still remains important due to its well-documented beneficial effect. Hormone receptor status is often reported as "positive" or "negative" using 10% positive nuclei as a cutoff. In this study, we aimed to assess whether a further subclassification of hormone receptor status could enhance the treatment predictive value. EXPERIMENTAL DESIGN: The immunohistochemical expression of estrogen receptor (ER) and progesterone receptor (PR) was quantified in tissue microarrays with tumors from 500 premenopausal breast cancer patients previously included in a randomized trial of adjuvant tamoxifen compared with an untreated control group. RESULTS: Our findings show a gradually increasing tamoxifen effect in tumors with >10% ER-positive nuclei. However, when analyzing tamoxifen response according to various PR fractions, we found that it was primarily patients with tumors showing >75% PR-positive nuclei that responded to tamoxifen treatment, with an improved recurrence-free [relative risk, 0.42 (0.25-0.70); P = 0.001] as well as overall [relative risk, 0.49 (0.28-0.84); P = 0.010] survival. CONCLUSIONS: Adjuvant tamoxifen improved recurrence-free and overall survival for premenopausal patients with tumors showing >75% PR-positive nuclei. No effect could be shown in tumors with fewer PR-positive nuclei. The PR was a stronger predictor of treatment response than the ER. Based on these findings, we suggest the implementation of a fractioned rather than dichotomized immunohistochemical evaluation of hormone receptors in clinical practice, possibly with greater emphasis on the PR than the ER.     

Cell cycle expression of steroid receptors determined by image analysis on human breast cancer cell line: A hypothesis on the effects of antiestrogens

Tamoxifen is the widespread anti-hormonal compound used for the treatment of human breast cancer. It is admitted that its effects are mediated via estrogen receptors (ER) but the molecular basis of its activity has yet to be clearly defined. In this work, we have developed a new image cytometry procedure in order to clarify the interactions between steroid receptors and tamoxifen at the cell cycle kinetic level. On untreated cells, an increase of ER level and a decrease of progesterone receptor (PR) level during the G0/G1 phase were demonstrated. Then, the ER and PR levels fell during the S-phase until the beginning of G2/M phase, where an increase was observed, especially for PR. These results suggest that ER is synthesized preferentially during the G0/G1 transition and PR during the S/G2 transition. After short-term tamoxifen treatment an augmentation of ER level was observed which was not dose-dependent, suggesting an increase in receptor translation rather than an augmentation of ER synthesis. PR level declined in the majority of the population leading to a selection of a subset of proliferating PR negative cells after treatment. These data demonstrate that the synthesis of steroid receptors is linked with the progression of cells through the cell cycle and indicate that tamoxifen blocks MCF-7 cells in G1 via its interactions with ER. Our multifluorescence imaging procedure appears to provide a rapid and quantitative approach which is useful for investigating alterations in steroid receptors after endocrine treatment.     

Steroid Hormone Receptor Positive Breast Cancer Patient-Derived Xenografts

The vast majority of breast cancers are positive for estrogen receptor (ER) and depend on estrogens for growth. These tumors are treated with a variety of ER-targeted endocrine therapies, although eventual resistance remains a major clinical problem. Other steroid hormone receptors such as progesterone receptor (PR) and androgen receptor (AR) are emerging as additional prospective targets in breast cancer. The fundamental mechanism of action of these steroid receptors in gene regulation has been defined mainly by several breast cancer cell lines that were established in the late 1970s. More recently, breast cancer patient-derived xenografts (PDX) have been developed by multiple groups at institutions in several countries. These new models capture the large degree of heterogeneity between patients and within tumors and promise to advance our understanding of steroid hormone receptor positive breast cancer and endocrine resistance. Unfortunately, steroid hormone receptor positive breast cancers are much more difficult than their receptor negative counterparts to establish into sustainable PDX. Herein we discuss the derivation of steroid hormone receptor positive breast cancer PDX, several pitfalls in their genesis, and their utility in preclinical and translational steroid hormone receptor research.     

Estrogen and progesterone receptor levels in nonneoplastic breast epithelium of breast cancer cases versus benign breast biopsy controls

Background  

Previous studies and biological mechanisms of carcinogenesis suggest that the steroid receptor content of benign breast epithelium may be related to breast cancer risk. The objective in this study was to compare the levels of estrogen receptor-α (ER) and progesterone receptor (PR) in nonneoplastic breast epithelium between breast cancer cases and biopsy controls.     

绝经后乳腺癌雌、孕激素受体状态与血清性激素水平的关系

目的探讨绝经后乳腺癌雌激素受体(ER)、孕激素受体(PR)状态与患者血清性激素水平的关系及意义。方法使用全自动免疫分析仪化学发光分析法检测41例乳腺癌患者血清性激素六项(LH、FSH、PRL、E2、P、T)水平,免疫组化EnVision二步法检测乳腺癌ER、PR表达状态。结果绝经后乳腺癌PR阴性组与PR阳性组比较,患者血清LH、FSH水平显著增高(P值分别为0.005和0.031),PRL、E2、P、T水平在二组间差异无统计学意义;在ER阴性组与ER阳性组之间所测性激素水平差异无统计学意义。结论绝经后乳腺癌PR表达状态可能与垂体激素LH、FSH水平有关。     

Progesterone receptor is a significant factor associated with clinical outcomes and effect of adjuvant tamoxifen therapy in breast cancer patients

Estrogen receptor status in breast cancer is associated with response to hormonal therapy and clinical outcome. The additional value of progesterone receptor (PR) has remained controversial. We examine the value of PR for prognosis and response to tamoxifen on a population-based series of 4,046 invasive early stage breast cancer patients. Clinical information for age at diagnosis, stage, pathology, treatment and outcome was assembled for the study cohort; the median follow-up was 12.4 years. PR status was determined by immunohistochemistry using a rabbit monoclonal antibody on tissue microarrays built from breast tumor surgical excisions. Survival analyses, Kaplan–Meier functions and Cox proportional hazards regression models were applied to assess the associations between PR and breast cancer specific survival. Progesterone receptor was positive in 51% of all cases and 67% of estrogen receptor positive (ER+) cases. Survival analyses for both the whole cohort and ER+ cases given tamoxifen therapy showed that patients with PR+ tumors had 24% higher relative probability for breast cancer specific survival as compared to PR− patients, adjusted for ER, HER2, age at diagnosis, grade, tumor size, lymph node status and lymphovascular invasion covariates. Higher PR expression showed stronger association with patient survival. Log-likelihood ratio tests of multivariate Cox proportional hazards regression models demonstrated that PR was an independent statistically significant factor for breast cancer specific survival in both the whole cohort and among ER+ cases treated with tamoxifen. PR adds significant prognostic value in breast cancer beyond that obtained with estrogen receptor alone.     

Steroid hormone receptors in male breast diseases

Estrogen (ER), progesterone (PR), glucocorticoid (GR) and androgen (AR) receptors were assayed in tumor samples from 8 cases of male breast cancer (MBC) and 20 cases of male gynecomastia. Seven out of eight (87.5%) male tumor samples had positive ER assays with values ranging from 12 to 180 fmol/mg protein. Of the seven ER positive cases of MBC, six, had positive PR activity with high titers. Positive GR and AR values were also detected in 75% of MBC cases. Concentrations of all four receptors were significantly correlated with each other. With gynecomastic tissue, the proportion of receptor-positive patients was 20% ER, 20% PR, 20% AR, and 45% GR. Except for GR, steroid receptor values for MBC individuals were significantly higher than those of gynecomastia patients.     

Sex steroid receptor expression in ‘carcinoid’ tumours of the breast

Summary Nine carcinoids of the breast (argyrophilic carcinomas) were examined for the presence of estrogen receptor (ER), progesterone receptor (PR), and androgen receptor (AR), using immunohistochemistry. The tumours were selected on the basis of their histo-morphological appearance and positive Grimelius stain. All cases were immunoreactive for neuron-specific enolase (NSE). In one case the tumour cells were intensely chromogranin A positive. All cases were ER positive, while 5 cases expressed AR and 5 cases PR. Immunostaining for ER and simultaneous demonstration of argyrophilia or chromogranin A expression in chromogranin A positive argyrophilic carcinoid tumour of the breast provided further evidence that neuroendocrine cells in breast tumours express sex steroid receptors. The similarity in sex steroid receptor expression pattern in carcinoids of the breast and the more common categories of breast cancer suggests an identical responsiveness to endocrine therapy.     

Estrogen receptors,progesterone receptors,and cell proliferation in human breast cancer

Summary The breast is a target organ for estrogens and progesterone. These hormones control several functions of the normal and abnormal mammary epithelium including cell proliferation. Most of the actions of estrogens and progesterone are mediated via specific steroid receptors, and one would expect that proliferating cells should contain estrogen receptors (ER) and/or progesterone receptors (PR). However, the correlation between receptor expression and cell proliferation is still controversial. In the present study we have examined 29 human breast cancer samples; in 17 of them we evaluated the simultaneous ER and PR localization with that of proliferating cell nuclear antigen (PCNA) and silver-stained nucleolar organizer regions (AgNORs) in a cell-by-cell study. We found that in almost 50% of the tumor biopsies examined, the cells expressing ER were significantly associated with elevated cell proliferation. In another group (38%) there were not significant differences between ER expression and cell proliferation. In only one of the samples (6%) the cells expressing ER showed lower cell proliferation. The study also revealed that in 44% of the tumors the PR expressing cells were associated with elevated cell proliferation. In a second group the PR expression was not significantly associated with cell proliferation (33% of the cases). Finally, in 22% of the samples the cells carrying PR showed lower cell proliferation. We also detected lower ER immunoreactivity in 30% of the breast cancer biopsies with one of the monoclonal antibodies against ER (antibody 1D5 directed against the A/B domain). This group of tumors was PR-negative (or very weakly positive) and had high proliferation. The presence of tumors with abnormal ER proteins and displaying ER/PR significantly associated with elevated cell proliferation could have implications in human breast cancer treatment.     

Plasma melatonin and the hormone-dependency of human breast cancer

We studied the 24-hour plasma melatonin profile in three groups of women: normal individuals, women with breast cancer, and women at high risk for breast cancer, to determine the relationship of plasma melatonin to this malignancy. The mean daytime (nadir) and mean nighttime (peak) plasma levels for the normal subjects were 9.1 pg/mL and 70.9 pg/mL, respectively. The mean daytime and nighttime plasma levels, and the range of melatonin day to night differences for women with breast cancer and women at high risk for breast cancer were comparable to each other and to the normal subjects, with no statistically significant differences noted. The patients with breast cancer demonstrated a striking correlation between the melatonin diurnal rhythm and the steroid receptor content of the primary tumor. Women with estrogen (ER) or progesterone (PR) receptor-positive tumors had a significantly lower mean plasma melatonin day to night difference than did patients with ER- or PR-negative tumors. Further, a strong inverse correlation was observed between the plasma melatonin concentration and the quantities of ER and PR in the primary tumor: the lower the plasma melatonin concentration the greater the amount of either receptor in the primary tumor. Plasma melatonin did not correlate with tumor glucocorticoid receptor content or stage of breast cancer among these patients, or with menopausal status, age, parity, or the plasma levels of estrone, estradiol, progesterone, follicle-stimulating hormone (FSH), or luteinizing hormone (LH) among all individuals studied. Plasma melatonin was also independent of the degree of risk for breast cancer among the high-risk patients. These findings suggest an important relationship between the plasma melatonin diurnal rhythm and the hormone dependency of human breast cancer, and may have implications for both the prognosis and treatment of this malignancy.     

Female sex steroid receptor status in primary and metastatic breast carcinoma and its relationship to serum steroid peptide hormone levels

In order to obtain more information on the interrelationships between cytosol estrogen (ER) and progestin (PR) receptors in breast carcinoma, and their distribution according to age, menopausal status and endocrine parameters of the patients, these receptors were measured in 605 primary and 150 metastatic lesions, and correlated with serum levels of estradiol, progesterone, FSH, LH and prolactin in some of these patients. Measurable estrogen receptor (> 3 fmol/mg cytosol protein) was found in 78.0% and progestin receptor (> 10 fmol/mg cytosol protein) in 60.5% of all the samples studied. The receptors were simultaneously present in 57.2%, estrogen receptor only in 20.8%, progestin receptor only in 3.3%, while both receptors were absent in 18.7% of the whole material. In samples from 253 premenopausal patients, measurable ER was found less frequently (71.1% of cases) and its concentration was lower (39.9 ± 5.1 fmol/mg cytosol protein, mean ± SEM) than in 502 postmenopausal patients (82%; 148.2 ± 11.6 fmol/mg). The frequencies of ER-positive samples and ER concentration were rather similar in primary and metastatic lesions, whereas PR was more often present (64 versus 47%) and its concentrations significantly higher (151.2 ± 12.5 versus 102.6 ± 21.1 fmol/mg) in primary than in metastatic tumors. When present simultaneously, there was a significant correlation between ER and PR concentrations in both primary and metastatic lesions independent of the menopausal status of the patient. ER concentration correlated significantly with age in both pre- and postmenopausal patients, while PR concentration correlated with age only in postmenopausal patients. The group with the highest ER values (above 100 fmol/mg cytosol protein) had a significantly lower serum estradiol concentration that the other patients. Serum estradiol values had a significantly positive correlation with cytosol PR content in the samples with a measurable PR. Serum progesterone, FSH, LH and prolactin did not correlate with tumor ER or PR concentrations. We conclude that concomitant assays of ER and PR from a breast carcinoma specimen provide a correct picture of the endocrine characteristics of the tumor independently of the serum concentrations of estradiol, progesterone, FSH, LH and prolactin.     

Interrelations Between Cellular DNA Content, S-Phase Fraction, Hormone Receptor Status and Age in Primary Breast Cancer A Series of 1 342 Consecutively Detected Tumors

Estrogen and progesterone receptors were assessed by an immuno-biochemical method and DNA content was analysed by flow cytometry in a consecutive series of 1 342 frozen breast cancer samples. Forty-six percent of the ER-positive tumors were DNA diploid compared to 23% among ER-negative cases. The proportion of ER—/PR— cases was highest among hypertetraploid tumors (45%) and lowest among DNA diploids (13%). While receptor positivity and DNA ploidy were strongly related, no differences in mean receptor levels were detected when comparing DNA diploid and aneuploid cases of receptor positive tumors. In receptor positive tumors ER content—but not PR content—increased with age. S-phase fraction (SPF) was estimated in 1165 cases (87%) with an overall mean of 8.6%. Tumors with high S-phase levels and DNA hypodiploid tumors were significantly more often found in younger than in older patients. The frequency of DNA hypodiploidy was less than 1% among women older than 75 years, while it was 8% among those aged 40 years or younger. S-phase fraction was inversely related to ER and PR status. However, while mean SPF gradually decreased with increasing levels of PR, no significant difference in S-phase fraction was seen for ER concentrations just above the cut-off level for receptor positivity. Tumors positive for both receptors showed the same pattern of DNA ploidy as ER+/PR — tumors while differences in S-phase fraction were observed between the groups. These results support that PR status better than ER status reflects hormone dependent growth in breast cancer.     

Steroid receptors and their role in the biology and control of breast cancer growth

Steroid hormone receptors (estrogen receptor [ER] and progesterone receptor [PR]) play a critical role in the development of breast cancer. Most importantly, the expression of ER and/or PR by tumor cells provides important information that is critical for the selection of treatment. Recent studies on ER and PR have provided new insights into the pathogenesis of breast cancer and the mechanisms of resistance to antihormonal therapy. Better understanding of steroid receptors, their ligands, and the mechanisms through which they exert their effects will allow the correct treatment to be targeted to responsive tumors.     

Steroid hormone receptor expression in male breast cancer.

AIMS: To investigate expression of the steroid hormone receptors estrogen receptor (ER)-alpha and -beta, progesterone receptor (PR) and androgen receptor (AR) in male breast cancer. METHODS: Specimens from 16 male breast cancers were immunostained for ERalpha, ERbeta, PR and AR. FINDINGS: Eighty-seven percent of tumours expressed ERalpha, 93% PR, 87% ERbeta and 87% AR. Staining for ERalpha and PR was confined exclusively to the nuclei of epithelial cells with some heterogeneity. Nuclear immunoreactivity was also observed with AR. Again this was restricted to epithelial cells but tended to be more uniform. ERbeta was seen in the nuclei of epithelial cells and also in stromal fibroblasts and lymphocytes. Analysis of serial sections revealed a similar pattern of staining with ERbeta and AR in epithelial cells. CONCLUSIONS: In addition to expression of the better known steroid receptors, ERalpha, PR and AR, we have demonstrated a high rate of expression of ERbeta in male breast cancer. This is in keeping with the generally high steroid receptor expression seen in males. However, the abundance of ERbeta expressed in this small series of male breast cancer is in contrast to female breast cancer where ERbeta expression is often reduced.     

乳腺增生病雌、孕激素受体表达及临床意义

目的:探讨乳腺增生病变组织中雌、孕激素受体表达情况,及其临床意义。方法:将乳腺增生病患者手术切除标本,常规福尔马林固定,石蜡包埋,采用免疫组化S-P法,测定ER、PR表达。结果ER和PR总阳性率74.36%(27/39)和87.18%(34/39),ER、PR同时阳性为66.67%(26/39)。本组不典型增生6例ER和PR阳性率均为100%,其表达强度最强,其次为腺病伴腺瘤形成,最弱为小叶增生。结论:乳腺增生病变组织中ER、PR虽然呈高表达,是三苯氧胺(TAM)治疗的适应症,但仍有25.64%的患者ER呈阴性表达,因此,用TAM治疗乳腺增生病前应检测患者的ER和PR,阳性者可用TAM治疗。     

Age interacts with the expression of steroid and HER-2 receptors in operable invasive breast cancer

BACKGROUND: The negative association between the oestrogen receptor (ER) and the human epidermal growth factor receptor 2 (HER-2) in breast cancer travels in both directions. ER+ tumours are less likely HER-2+ and HER-2+ tumours are less likely ER+. METHODS: We studied the age-related immunohistochemical (IHC) expression of ER, progesterone receptor (PR) and HER-2 in 2,227 tumours using age as a continuous variable. Steroid receptors were considered positive for any nuclear staining of invasive cancer cells and for HER-2, either for strong expression by IHC (score 3+) or gene amplification by fluorescence in situ hybridisation (FISH). Based on nonparametric regression, the age-related association between steroid receptors and HER-2 was presented as likelihood curves. RESULTS: The association between ER or PR and HER-2 is age-related. The age-related expression of ER and PR is HER-2 dependent. In HER-2(-) cases, the odds ratio (OR) for being ER+ was 2.594 (95% CI = 1.874-3.591) up to age 50 and age-independent thereafter; for PR-expression the OR was 2.687 (95% CI = 1.780-4.057) up to age 45 and 0.847 (95% CI = 0.761-0.942) thereafter. In HER-2+ cases, the OR was 0.806 (95% CI = 0.656-0.991) to be ER+ and 0.722 (95% CI = 0.589-0.886) to be PR+. The age-related OR for breast cancers to be HER-2+ is steroid receptor dependent. Taking together, ER+PR+HER-2+ breast cancers appear on average 5.4 years earlier than breast cancers of any other ER/PR/HER-2 phenotype (95% CI = 3.3-7.5; P < 0.0001). CONCLUSION: There is a qualitative interaction between age and expression of steroid and HER-2 receptors. Our findings suggest a strong age-related selective growth advantage for breast tumour cells belonging to the ER+PR+HER-2+ subgroup.     

Progesterone receptors - animal models and cell signaling in breast cancer: The role of oestrogen and progesterone receptors in human mammary development and tumorigenesis

A relatively small number of cells in the normal human mammary gland express receptors for oestrogen and progesterone (ER and PR), and there is almost complete dissociation between steroid receptor expression and proliferation. Increased expression of the ER alpha (ERα) and loss of the inverse relationship between receptor expression and proliferation occur at the very earliest stages of tumorigenesis, implying that dysregulation of ERα expression contributes to breast tumour formation. There is evidence also for alterations in the ratio between the two PR isoforms in premalignant breast lesions. Elucidation of the factors mediating the effects of oestradiol and progesterone on development of the normal breast and of the mechanisms by which expression of the ERα and the PR isoforms is controlled could identify new targets for breast cancer prevention and improved prediction of breast cancer risk.     

The role of oestrogen and progesterone receptors in human mammary development and tumorigenesis

A relatively small number of cells in the normal human mammary gland express receptors for oestrogen and progesterone (ER and PR), and there is almost complete dissociation between steroid receptor expression and proliferation. Increased expression of the ER alpha (ERalpha) and loss of the inverse relationship between receptor expression and proliferation occur at the very earliest stages of tumorigenesis, implying that dysregulation of ERalpha expression contributes to breast tumour formation. There is evidence also for alterations in the ratio between the two PR isoforms in premalignant breast lesions. Elucidation of the factors mediating the effects of oestradiol and progesterone on development of the normal breast and of the mechanisms by which expression of the ERalpha and the PR isoforms is controlled could identify new targets for breast cancer prevention and improved prediction of breast cancer risk.