A novel flow cytometric steroid hormone receptor assay for paraffin-embedded breast carcinomas: an objective quantification of the steroid hormone receptors and direct correlation to ploidy status and proliferative capacity in a single-tube assay

Semiquantitative estimation of steroid hormone receptors by immunohistochemistry applied to paraffin sections is common practice in surgical pathology. Flow cytometric (FCM) analysis of estrogen receptor (ER) and progesterone receptor (PR) levels provides a faster and more objective quantitative assay. However, a major problem in such FCM analyses of solid tumor samples is the admixture of tumor cells with normal epithelial, stromal, and inflammatory cells. The aim of the underlying study was to investigate the applicability of a recently developed multiparameter flow cytometric methodology for the accurate estimation of the fraction of steroid hormone receptor-positive tumor cells and to explore whether this multiparameter approach allows the detection of specific, clinically relevant subsets of tumors, based on a combination of ploidy level, steroid hormone receptor status, and cell cycle characteristics. For this purpose, samples of 42 breast cancer patients, from which routine immunohistochemistry for ER and PR also was available, were analyzed. From each case, a cell suspension was prepared from the paraffin block by applying a heating and short pepsin digestion step to 50-microm-thick sections. These cell suspensions were double-immunostained for cytokeratin to identify the epithelial cells, and ER or PR, whereas DNA was quantitatively stained with propidium iodide using an optimized protocol. In the entire group of breast tumors, the percentages of ER- and PR-positive cells were registered in the epithelial subfraction, in combination with DNA ploidy and S phase fraction (SPF). A significant correlation was found between the fraction of hormone receptor-positive cells as found by the immunohistochemical and FCM procedures. For ER, a correlation coefficient of r = .87 was found, and for PR r = .62, both P < .0001. It became clear that all the diploid breast tumors had more than 30% tumor cells positive for ER with a SPF lower than 10%, whereas aneuploid tumors contained on average a smaller percentage of steroid hormone receptor-positive cells, and simultaneously an SPF greater than 10%. Our results show that this multiparameter FCM analysis allows an objective and reproducible quantification of the fraction of steroid hormone receptor-positive cells in the relevant epithelial cell compartment in relation to DNA ploidy status and proliferative capacity in a single-tube assay.     

Expression of steroid hormone receptors, their regulated proteins, and bcl-2 protein in myofibroblastoma of the breast

AIMS: To investigate the possible role of steroid hormones in the pathogenesis of myofibroblastoma (MFB) of the breast, we analysed the immunohistochemical expression of oestrogen, progesterone, androgen receptors, their regulated proteins and bcl-2 protein in a series of this rare tumour. METHODS AND RESULTS: Paraffin-embedded sections from seven cases of MFB of the breast (five male; two female) were immunohistochemically tested for the expression of oestrogen receptor (ER), progesterone receptor (PR), androgen receptor (AR), oestrogen-regulated pS2 protein, androgen-regulated prostate-specific antigen (PSA) and bcl-2 protein. Rare cases of benign spindle cell tumours or tumour-like lesions of the breast (primitive fibromatosis, inflammatory pseudotumour, muscular hamartoma) which enter into the differential diagnosis with MFB, were also investigated and compared with MFB. All cases of MFB showed a diffuse (70-90% of neoplastic cells) and strong nuclear labelling with ER and PR, whereas AR was expressed only in three cases (two men and one woman) in about 60-70% of cells. Conversely, no immunostaining was detected for the pS2 protein and PSA. bcl-2 protein immunoreactivity was found in all cases of MFB, although with a variable degree of expression. No expression for steroid hormone receptors, their regulated-proteins and bcl-2 protein was observed in the rare benign spindle cell lesions of the breast included in this study. CONCLUSION: The in-situ detection of ER, PR and AR suggests that steroid hormones and their receptors are implicated in the pathogenesis of breast MFB. The consistent demonstration of bcl-2 protein, associated with a positive ER/PR status, provides evidence that bcl-2 may be an oestrogen-regulated protein also in MFB and that probably plays a role in the tumorigenesis. Finally, we postulate that the ER/PR and bcl-2 positive immunoprofile of MFB of the breast, in contrast to the negative profile of other rare primitive benign spindle cell lesions of the breast herein studied, might be exploited as an ancillary diagnostic aid in differential diagnosis of doubtful cases.     

Immunohistochemical localization of oestrogen receptors and progesterone receptors in the human ovary throughout the menstrual cycle

Summary Immunohistochemistry was used to determine the distribution of oestrogen receptors (ER) and progesterone receptors (PR) in the human ovary during folliculogenesis. Primordial and preantral follicles did not contain ER or PR. The granulosa cells of antral follicles had ER, but negligible PR, before the LH surge. In contrast, at the time of LH surge, these cells of the dominant follicle contained PR, but not ER. On the other hand, granulosa cells of the non-dominant follicles had ER, but not PR. After ovulation, the PR persisted in the luteinized granulosa cells and in the corpus luteum during early pregnancy. The theca interna and surrounding stromal cells were ER-negative and PR-positive throughout the menstrual cycle. Thus, the results show that ER and PR are not expressed simultaneously in the granulosa cells, the thecal cells, or the stromal cells during folliculogenesis. Mechanisms controlling the expression of steroid receptors during the normal menstrual cycle and in early pregnancy are discussed.     

Mammosphere‐derived gene set predicts outcome in patients with ER‐positive breast cancer

Tumourigenic subpopulations with stem cell‐like features have been identified in breast tumours and breast cancer cell lines. The hormone receptor status, molecular characteristics and clinical significance of these cells are still matters of debate. Enrichment for tumourigenic cells without the requirement of surface markers can be achieved by the in vitro mammosphere culture assay. Here we compared the hormone receptor status and genome‐wide gene expression profiles of mammospheres derived from four oestrogen‐receptor (ER) positive breast cancer cell lines with those of the respective parental cells. Immunohistochemistry and gene expression profiling revealed a significant reduction in the expression of progesterone receptor, proliferation and cell cycle regulated genes in mammospheres when compared to parental cell lines. The 200 most differentially expressed genes between mammospheres and parental cell lines were used to generate a ‘mammosphere‐derived’ gene set. Hierarchical clustering of gene expression profiles of two independent cohorts of primary ER‐positive cancers based on the ‘mammosphere‐derived’ gene set revealed that the subgroup of breast cancers with profiles similar to those of mammospheres has a significantly longer overall survival. In conclusion, tumour‐initiating breast cancer cells grown in mammospheres seem to reside in a quiescent state. ER‐positive breast cancers with expression profiles similar to those of mammospheres have a better outcome, providing evidence in support of the concept that outcome of patients with ER‐positive disease is for a large part determined by cell cycle and proliferation activity. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Mesothelial markers in high-grade breast carcinoma

Duhig E E, Kalpakos L, Yang I A & Clarke B E
(2011) Histopathology 59 , 957–964 Mesothelial markers in high‐grade breast carcinoma Aims: Advances in molecular profiling have subdivided breast carcinomas into distinct subtypes. Basal carcinomas are generally oestrogen receptor (ER)?progesterone receptor (PR)?/human epidermal growth factor receptor 2 (HER2)?, and cytokeratin (CK)5/6+. This profile overlaps with that of mesothelial cells. This study of high‐grade breast carcinomas was undertaken to determine the expression of mesothelial markers. Methods and results: Immunohistochemistry was performed on 23 basal‐like breast carcinomas and 30 high‐grade breast carcinomas with variable ER, PR and HER2 expression. The incidence of staining of CK5/6, CK14, calretinin, Wilms’ tumour 1 (WT1), thrombomodulin and epithelial membrane antigen was assessed statistically. CK14 staining was more specifically associated with triple‐negative tumours than CK5/6. Calretinin positivity was statistically associated with basal‐like carcinomas. WT1 and thrombomodulin expression was infrequent and limited to a small number of non‐basal carcinomas. Conclusions: There is an overlap between the immunophenotype of mesothelial cells and that of basal‐like carcinomas of breast. Positive calretinin and CK5/6 are not specific, and may be seen in both mesothelial cells and basal‐like breast carcinomas. Negative ER and PR of basal carcinomas may also bias the observer against a breast origin. However, other negative mesothelial markers, such as WT1 and thrombomodulin, may help point to the correct diagnosis.     

Steroid hormone receptor in pleural solitary fibrous tumours and CD34+ progenitor stromal cells

Solitary fibrous tumours (SFT), originally described in the pleura, were subsequently recognized in numerous extrapleural sites. This suggests that a common stem cell, present in various organs and tissues, may be at the origin of SFT and that specific factors may be involved in the proliferation of such cells. Recently it has been described that steroid hormone receptors, progesterone receptors in particular, are expressed by extrapleural SFT. In addition, progesterone may participate as growth factor in many CD34(+) stromal neoplasms, which express low levels of the hormone receptors. The present study analysed the expression of androgen (AR), oestrogen (ER) and progesterone (PR) receptors in a series of 32 pleural SFT, 10 mesotheliomas and in reactive tissue of chronic pleuritis. ER and AR were never expressed by SFT or by chronic pleuritis, whereas PR were demonstrated in 2/16 "large" (>8 cm) and in 6/16 "small" (< or =8 cm) pleural SFT (all expressing CD34, bcl-2 and CD99). PR(+) SFT had a significantly higher proliferative activity (p = 0.04) (Ki-67 mean value 6.5%) and lower p27(kip1) (mean value 51.5%) expression than the PR(-) cases (Ki-67 mean value 3.81% and p27(kip1) mean value 57.86%). One of the cases expressing a high level of PR (80%) recurred 1 year after first surgery and the recurrence was PR(+) as well, but with a lower percentage of nuclear receptor expression (12%). In addition, in chronically inflamed subserosal tissue, a subpopulation of CD34(+) endothelial and interstitial dendritic cells was identified, which also expressed PR. These findings suggest that the CD34(+) submesothelial interstitial dendritic cells, activated during reactive processes, may be the stem cells that give rise to SFT, and that progesterone might participate in the growth of SFT through modulation of its specific receptors.     

Assessment of results of estrogen and progesterone receptor assays performed in a community hospital

Approximately 1,000 assays for estrogen receptor (ER) in primary human breast tumors have been performed at St. Joseph's Hospital over a period of seven years; 700 of these included assays for progesterone receptor (PR). Based on the method of analysis (dextran-coated charcoal) and criteria for a positive result used for this survey, 80 percent of the primary tumors were ER-positive and 56 percent were PR-positive. In those cases where both assays were performed, 47.4 percent were ER-positive, PR-positive; 19.8 percent were ER-positive, PR-negative; 6.2 percent were ER-negative, PR-positive; and 26.6 percent were ER-negative, PR-negative. The mean concentration of ER increased with the advancing age of the patient; essentially the same relationship was observed for PR. The concentration of ER and PR was not directly dependent upon the degree of cellularity of the tumor. Lobular carcinoma and the mixed types containing ductal and lobular elements had the highest frequency of being positive for both steroid receptors, while medullary and papillary carcinomas were lowest. Three hundred and twenty-two cases had follow-up studies and were examined on the basis of the available information in the files of St. Joseph's Hospital Tumor Registry. A higher survival rate in patients with both ER and PR positivity became evident. In a community hospital setting, our data confirm the usefulness of estrogen and progesterone receptor assays in decisions of clinical management and considerations of prognosis in patients with mammary carcinoma.     

Breast cancer outcomes by steroid hormone receptor status assessed visually and by computer image analysis

Mohammed Z M A, Edwards J, Orange C, Mallon E, Doughty J C, McMillan D C & Going J J
(2012) Histopathology  61, 283–292 Breast cancer outcomes by steroid hormone receptor status assessed visually and by computer image analysis Aims: To compare the assessment of steroid hormone receptor immunohistochemistry by eye and by computer‐aided image analysis, and to examine their relationships with survival in breast cancer. Methods and results: Allred scores and weighted histoscores for oestrogen receptor (ER) and progesterone receptor (PR) immunohistochemistry were determined by eye (visual histoscore) for 459 primary invasive ductal breast carcinomas in triplicate tissue microarrays. Histoscores were also determined by computerized image analysis (automated histoscore). ER and PR status determined by these different methods were compared with each other and in their ability to predict survival over at least 142 months of follow‐up. Allred and visual histoscore were highly associated for ER and PR (both P < 0.001). By univariate analysis, Allred score and visual histoscore for ER and PR were highly associated with recurrence‐free and cancer‐specific survival (both P < 0.001) in patients with invasive ductal breast cancer overall, in those who received tamoxifen, and in those with recurrence on tamoxifen. Visual and automated histoscores were in excellent agreement for ER and PR (both P < 0.001), and were equally effective in predicting recurrence and survival for patients with invasive breast cancer who received tamoxifen. Conclusions: Automated histoscore appears to be a valid alternative to visual histoscore or Allred score for determining ER and PR status.     

Role of ERRF, a novel ER-related nuclear factor, in the growth control of ER-positive human breast cancer cells

Whereas estrogen-estrogen receptor α (ER) signaling plays an important role in breast cancer growth, it is also necessary for the differentiation of normal breast epithelial cells. How this functional conversion occurs, however, remains unknown. Based on a genome-wide sequencing study that identified mutations in several breast cancer genes, we examined some of the genes for mutations, expression levels, and functional effects on cell proliferation and tumorigenesis. We present the data for C1orf64 or ER-related factor (ERRF) from 31 cell lines and 367 primary breast cancer tumors. Whereas mutation of ERRF was infrequent (1 of 79 or 1.3%), its expression was up-regulated in breast cancer, and the up-regulation was more common in lower-stage tumors. In addition, increased ERRF expression was significantly associated with ER and/or progesterone receptor (PR) positivity, which was still valid in human epidermal growth factor receptor 2 (HER2)-negative tumors. In ER-positive tumors, ERRF expression was inversely correlated with HER2 status. Furthermore, higher ERRF protein expression was significantly associated with better disease-free survival and overall survival, particularly in ER- and/or PR-positive and HER2-negative tumors (luminal A subtype). Functionally, knockdown of ERRF in two ER-positive breast cancer cell lines, T-47D and MDA-MB-361, suppressed cell growth in vitro and tumorigenesis in xenograft models. These results suggest that ERRF plays a role in estrogen-ER-mediated growth of breast cancer cells and could, thus, be a potential therapeutic target.     

Immunohistochemical detection of the estrogen receptor‐α and progesterone receptor in the canine pregnant uterus and placental labyrinth

The presence of hormone receptors is as important as the amount of hormone to predict hormone action. Therefore, the presence of estrogen receptors of the alpha subtype (ER‐α) and progesterone receptors (PR) was evaluated in six pregnant uteri including the placenta and in three postpartum uteri of dogs. This preliminary study is part of our immunohistochemical research project on steroid hormone receptor distribution in the canine female genital tract. Specific staining for ER‐α or PR was found only in cell nuclei. Staining for ER‐α was rare in the various cell types of pregnant and postpartum uteri. Staining for PR was absent or weak in epithelial cells. Moderate staining for PR was observed in endometrial stromal cells and myometrial smooth muscle cells, two cell types playing an important role in the maintenance of pregnancy. Stromal cells stained more frequently positive for ER‐α and PR than epithelial cells, indicating that both hormones may act on epithelial cells indirectly via stromal cells. In the placental labyrinth, fetal cells showed no evidence of ER‐α or PR. In contrast, both receptors were present in maternal mesenchymal cells that were located around the basement membrane of the maternal blood vessels. These cells showed signs of decidualization. No difference in PR distribution was seen between pregnant and postpartum uterine tissue, suggesting that during parturition the decrease in serum progesterone levels and the concomitant increase in the estrogen/progesterone ratio are probably more important than the decline in receptor availability. Anat Rec 260:42–50, 2000. © 2000 Wiley‐Liss, Inc.     

Expression of EGFR Family and Steroid Hormone Receptors in Ductal Carcinoma in situ of the Breast

The expression of EGFR family and steroid hormone receptors was examined in a series of 40 cases of pure ductal carcinoma in situ (DCIS) of the breast by immunohistochemical staining of paraffin-embedded sections. Hematoxylin and eosin-stained sections were used to classify the tumors according to the published criteria by Holland et al. (Holland R, Peterse JL, Millis RR, et al. Semin Diagn Pathol. 1994;11:167-180). Of the tumors 48% were immunoreactive for EGFR, 63% for c-erbB-2, 78% for c-erbB-3, 95% for c-erbB-4, 88%for estrogen receptor (ER) and 80% for progesterone receptor (PR). Statistically significant association between histological grade (differentiation) and c-erbB-2 protein expression was seen ( p <.001). In addition, expression of c-erbB-4 protein was associated with c-erbB-2 ( p =.004), c-erbB-3 ( p =.058), ER ( p =.002) and PR ( p =.004). It is concluded that c-erbB-2 expression in DCIS is associated with high-grade pathological features, and a higher c-erbB-2 expression is seen in DCIS than in invasive breast carcinomas. A possible association between extensive expression of c-erbB-4 and steroid hormone receptors in proliferative and premalignant breast epithelial cells and the c-erbB-2 expression in DCIS and invasive breast carcinomas is discussed.     

Expression of EGFR family and steroid hormone receptors in ductal carcinoma in situ of the breast.

The expression of EGFR family and steroid hormone receptors was examined in a series of 40 cases of pure ductal carcinoma in situ (DCIS) of the breast by immunohistochemical staining of paraffin-embedded sections. Hematoxylin and eosin-stained sections were used to classify the tumors according to the published criteria by Holland et al. (Holland R, Peterse JL, Millis RR, et al. Semin Diagn Pathol. 1994;1 1:167-180). Of the tumors 48% were immunoreactive for EGFR, 63% for c-erbB-2, 78% for c-erbB-3, 95% for c-erbB-4, 88% for estrogen receptor (ER) and 80% for progesterone receptor (PR). Statistically significant association between histological grade (differentiation) and c-erbB-2 protein expression was seen (p <.001). In addition, expression of c-erbB-4 protein was associated with c-erbB-2 (p=.004), c-erbB-3 (p=.058), ER (p=.002) and PR (p=.004). It is concluded that c-erbB-2 expression in DCIS is associated with high-grade pathological features, and a higher c-erbB-2 expression is seen in DCIS than in invasive breast carcinomas. A possible association between extensive expression of c-erbB-4 and steroid hormone receptors in proliferative and premalignant breast epithelial cells and the c-erbB-2 expression in DCIS and invasive breast carcinomas is discussed.     

An immunohistochemical comparison of endometrial polyps from postmenopausal women exposed and not exposed to HRT

OBJECTIVE: Our study set out to test the null hypothesis that oestrogen containing continuous combined hormone replacement therapy (HRT) would not affect the hormone receptor expression (oestrogen and progesterone receptors-ER, PR) or markers of cell proliferation/apoptosis (Ki67 and Bcl-2) in endometrial polyps from postmenopausal women exposed and not exposed to HRT. DESIGN: Immunohistochemical staining for ER, PR, Ki67 and Bcl-2 was performed on polyps obtained from two groups of postmenopausal women. SETTING: Polyps were obtained from postmenopausal women attending an outpatient hysteroscopy clinic in a district general hospital (Bradford Royal Infirmary, UK). POPULATION: Twenty-five postmenopausal women presenting with abnormal bleeding subsequently diagnosed with endometrial polyps (16 from women not exposed to HRT, 9 from women exposed to HRT). METHODS: Semiquantitative immunohistochemistry was performed. MAIN OUTCOME MEASURES: Significant differences or correlations in either hormone receptor expression or markers of cell proliferation/apoptosis between the two groups of polyps. RESULTS: There were no significant differences for hormone receptor expression (ER and PR) between endometrial polyps exposed and not exposed to HRT. Bcl-2 expression was higher than Ki67 in both groups, but polyps from HRT users had increased levels reflecting decreased apoptosis in these polyps. CONCLUSIONS: HRT has no demonstrable effect on polyp ER and PR expression. However, HRT does appear to inhibit apoptosis and cell proliferation in endometrial polyps, which may affect polyp growth.     

The effect of hormone replacement therapy on the immunoreactive concentrations in the endometrium of oestrogen and progesterone receptor, heat shock protein 27, and human beta-lactoglobulin

We determined the expression of oestrogen receptor (ER), progesterone receptor (PR), heat shock protein 27 (HSP27) and human beta-lactoglobulin in the endometrium under hormone replacement therapy (HRT). The immunohistochemical expression during the late progestogenic phase of sequential HRT was compared semi-quantitatively and using image analysis, to the early, mid-, and late luteal phase of the physiological cycle. Under sequential HRT, smaller glands were positive for the ER but larger glands with more advanced secretory features were negative. ER expression was lower in the stroma under HRT, and the difference was statistically significant compared with the early luteal phase (P < 0.05). Expression of HSP27 under HRT was lower in the epithelium but higher in the stroma compared with the physiological luteal phase. Epithelial PR expression was lower under HRT compared with the early, but not the mid- or the late luteal phase. The number of PR-positive stromal cells under HRT was lower compared with the physiological cycle, and the difference was statistically significant in comparison with the early luteal phase (P < 0.05). The glandular area expressing human beta-lactoglobulin during the late progestogenic phase was statistically significantly higher compared with the early, but lower in comparison with the mid- or the late luteal phase (P < 0.05). The study demonstrates a sub-physiological progestogenic response superimposed on evidence of a hypo-oestrogenism, and a differential response in the epithelium and stroma.     

Hormone receptors in non-malignant meningiomas correlate with apoptosis,cell proliferation and recurrence-free survival

AIMS: A retrospective immunohistochemical and statistical analysis of patients with non-malignant meningiomas was undertaken to determine the correlation of steroid hormone receptor status with apoptosis, tumour cell proliferation, clinicopathological characteristics and prediction of recurrence. METHODS AND RESULTS: Paraffin sections from 51 primary intracranial totally resected benign and atypical meningiomas were immunohistochemically evaluated for the expression of progesterone (PR), oestrogen (ER) and androgen (AR) receptors, apoptotic rate, Bcl-2, p53 and Ki67 antigens. In addition to the above parameters, the mitotic index and the patients' clinicopathological data were statistically correlated and entered in a recurrence-free survival analysis. A high level of apoptotic cell death was associated with loss of PR expression by logistic regression analysis (P = 0.016). An inverse correlation existed between the mitotic index and PR counts (P = 0.009), while high Ki67 values correlated with increased ARs (P = 0.041). Atypical meningiomas had a lower ER staining score (P = 0.036). Multivariate analysis indicated that the absence of PR and large tumour size were significant factors for shorter disease-free intervals. CONCLUSIONS: The results suggest that ER expression is lost or reduced in atypical meningiomas, whereas loss of PR expression is an indicator of increased apoptosis and early recurrence. PRs and ARs may also influence tumour cell proliferation.     

Differential expression of estrogen, progesterone, and epidermal growth factor receptors in normal, benign, and malignant human breast tissues using dual staining immunohistochemistry.

Distribution of estrogen (ER), progesterone (PR) receptors, and epidermal growth factor (EGF) receptors was assayed by dual staining immunohistochemistry on 28 selected cytosolic ER-positive breast carcinomas and 22 nonmalignant breast tissues. ER-positive tumor cells were detected in 26 (93%) and EGF receptor positive tumor cells were detected in 7 (25%) carcinomas. In five tumors both ER and EGF receptors were detected but localized in distinct tumor cells. Only in one case of ductal carcinoma in situ co-expression was observed in a subset of tumor cells. In contrast, simultaneous expression of ER/PR and EGF receptors was observed in non-neoplastic ductal remnants in the majority of the carcinomas and the fibroadenomas. In addition, double-positive cells were occasionally detected in luminal epithelial cells of normal breast tissue and mastopathies. This study shows that ER/PR and EGF receptors in breast tumor cells are inversely related at the single cell level. However, demonstration of ER/PR and EGF receptors in individual normal luminal cells shows that expression is not mutually exclusive.     

Immunohistochemical analysis of estrogen receptor alpha, estrogen receptor beta and progesterone receptor in normal human endometrium

The endometrium expresses estrogen (ER) and progesterone receptors (PR), which are involved in autocrine and paracrine regulation processes in response to estrogen and progesterone. The aim of the present study was to evaluate immunohistochemical distribution patterns of estrogen receptor alpha (ER alpha), estrogen receptor beta (ER beta) and PR in normal human endometrial tissue with the use of monoclonal antibodies. Human endometria were obtained from 17 premenopausal patients undergoing surgery for non-malignant diseases and were classified to be in proliferative, early secretory and late secretory phases by histological and anamnestical means. Distribution patterns of the steroid receptors were evaluated using the IRS-score and the Mann-Whitney rank-sum test was used to compare the means. Correlation was assessed with the Spearman factor and linear regression analysis. ER alpha and PR expression decreased significantly (p<0.05) in glandular epithelium from the proliferative to the late secretory phase. ER beta expression showed a similar significant decrease (p<0.05), although staining intensity was lower than that of ER alpha. A significant correlation between expression of all three steroid receptors was observed (p<0.001). Distribution patterns of ER alpha, ER beta and PR in normal human endometrium showed a cyclic variation during the menstrual cycle. A significant correlation between expression of ER alpha, ER beta and PR was also demonstrated using regression analysis, indicating dependence of expression of these three steroid receptors. The present study shows the presence of steroid receptors in human endometrial epithelium, indicating that these cells respond to estrogen and progesterone and thus playing a significant role in endometrial physiology.     

Endometrial carcinoma: association of steroid hormone receptor expression with low angiogenesis and bcl-2 expression

In endometrial tissues, malignant change may be accompanied by a loss of hormone dependence which is, usually, reflected in a parallel loss of oestrogen and progesterone receptors (ER and PR). In this study, the steroid receptor status of 164 endometrial carcinomas was related to intratumoural angiogenesis and the apoptotic proteins bcl-2 and p53. Relationships to conventional histopathological features and patient survival were also sought. Immunohistochemistry was performed on formalin-fixed, paraffin-embedded tissues. The mean follow-up was 55 months (range 19-167 months). Specific nuclear staining for ER and PR was detected in 35% and 32% of endometrial carcinomas, respectively, and was very commonly co-expressed (P<0.0001). The failure of demonstrating a steroid receptor complement in endometrial neoplasms was, in general terms, an adverse prognostic sign. Thus, ER or PR loss was significantly associated with non-endometrioid carcinomas (ER P=0.01; PR P=0.004) and with deep myometrial invasion (ER P<0.0002), high intratumoural angiogenesis (PR P<0.01) and the absence of bcl-2 expression (PR P<0.005). There was a trend for patients with ER or simultaneous ER/PR expression to have an improved survival, but this association did not reach the level of statistical significance. In multivariate analysis (all stages), tumour cell type (endometrioid versus non-endometrioid carcinomas) and stage of disease were the only variables associated with prognosis (P=0.01 and P<0.0001, respectively), with tumour cell type retaining its independent prognostic value and within stage-I endometrial carcinomas (P=0.02). It is suggested that the loss of steroid hormone receptors in endometrial carcinomas is associated with a more aggressive phenotype and the switching-on of angiogenic pathways.