Estrogen and progesterone receptors in colorectal cancer and surrounding mucosa

In this prospective study we have quantified by means of ELISA-methods the cytosolic content of estrogen (ER) and progesterone receptors (PgR) in tumoral tissue and paired normal mucosa from 163 patients with resectable colorectal cancer. Survival analysis was performed in a subgroup of 120 patients and the mean follow-up period was 24.9 months. The cutoff for ER and PgR levels was set at 1 fmol/mg protein. On the basis of this cutoff 20.9% of the cancers were ER positive and 25.8% were PgR positive; normal adjacent tissue presented ER in 18.4% and PgR in 24.5%. Our results did not show any significant correlation between ER and PgR levels in neoplastic tissues. Howewer, a correlation was found in normal mucosa samples (p=0.02). Statistical analysis showed that there was no correlation between tumor ER and PgR content and patient age or sex, tumor location, Dukes' stage, histological differentiation, DNA ploidy status and S-phase fraction. Furthermore, the results did not show any statistical differences in relapse-free and overall survival curves calculated for patients classified according to the hormone receptor content of their tumors. ER and PgR were detected at low levels in normal and neoplastic colorectal tissues without any significant relationship to either clinicopathological tumor characteristics or patient outcome. Their possible role in colorectal cancer remains to be elucidated.     

Alterations of estrogen receptors, progesterone receptors and c-erbB2 oncogene protein expression in ductal carcinomas of the breast

Estrogens are important for stimulating the growth of a large proportion of breast cancers. Progesterone plays critical roles in breast development and tumorigenesis. The c-erbB2 gene (HER-2/neu) is a proto-oncogene expressed in 10-34% of breast cancers. Its expression is associated with poor clinical outcome. The hypothesis that the progression of in situ ductal carcinoma of breast to invasive ductal carcinoma is associated with alterations of ER, PgR and HER-2/neu protein expression was tested. Of 100 mastectomy specimens examined, all contained both ductal carcinoma in situ (DCIS) and invasive ductal carcinomas (IDC) not otherwise specified (NOS). The status of ER, PgR and HER-2/neu proteins was examined by immunochemistry. ER and PgR protein expression was scored as the mean value of positively stained cells. HER-2/neu protein expression was evaluated on ts staining pattern (0, 1+, 2+ and 3+). We found variations between DCIS and IDC with significant decrease of the mean values of ER and PgR positively stained cells in high-grade (Grade 3) IDC (ER: 49.2+/-10.3 vs. 30.8+/-5.5 and PgR: 40.0+/-10.0 vs. 22.3+/-5.1 in DCIS and IDC, respectively, P<0.05). Invasive carcinomas with lymph node metastases or lymphovascular invasion or both had lower mean values of ER and PgR positively stained cells compared to those without these features. In IDC (Grade 3), HER-2/neu protein expression values (1.2+/-0.2) were significantly high compared to DCIS (0.7+/-0.3, P<0.05). In addition, HER-2/neu protein expression values were significantly higher (P<0.05) in IDC with lymph node metastases or lymphovascular invasion (1.5+/-0.3) than those without these features (0.8+/-0.2). A significantly high mean (P<0.05) of ER and PgR positively stained cells was observed in postmenopausal females compared to premenopausal women. In contrast, high HER-2/neu expression values were seen only in premenopausal females. A significant positive correlation was observed between ER and PgR receptor expression (r=0.81). A low degree inverse correlation (r=-0.24, P<0.012) was found between ER+/PgR+ tumors and HER-2/neu expression. These findings substantiate the notion that breast cancer progression is often associated with alterations of ER, PgR and HER-2/neu expression. The underlying mechanisms of these alterations are open for further investigation.     

An investigation of cut-points for primary breast cancer oestrogen and progesterone receptor assays

Oestrogen and progesterone receptor (ER and PgR) assay values are frequently used in medical decision-making for breast cancer patients. We have proposed statistical standardization of receptor assay values to improve inter-laboratory comparability, and now report the use of standardized log units (SLU) to investigate the effects of ER and PgR cut-points on time to first recurrence outside the breast (DFS). Between 1980 and 1986, there were 678 primary breast cancer patients treated at the Henrietta Banting Breast Centre (HBBC). The effects of ER and PgR cut-points were examined with multivariate analyses considering the variables: age, tumour size, nodal status, weight and adjuvant treatment. We considered receptor assay cut-points ranging from −1.0 to +1.0 SLU (ER between 7 and 166 fmol/mg protein; PgR between 7 and 181 fmol/mg protein). PgR was included in the multivariate prognostic models more often than ER, although patients had a better prognosis with both larger ER and PgR values. There was no best cut-point for ER or PgR, and there was strong evidence that ER and PgR should be considered as continuous rather than dichotomous (negative, positive) variables. Patient prognosis should also be more comparable with SLU.     

MUC3 and MCA serum levels and steroid receptor content in breast cancer

Mucins are an important class of complex glycoproteins expressed by many epithelial cells and their malignant counterparts. The aim of this study was to determine the serum levels of MUC3 and mucin-like carcinoma-associated antigen (MCA) in patients with primary breast cancer and to analyze the possible relationships between these two mucins and the steroid receptor status. The preoperative basal serum levels of MUC3 (ELISA assay with monoclonal antibody 1143/B7) and MCA (EIA assay with anti-MCA mouse monoclonal antibody b-12) were determined in 44 patients with breast cancer while estrogen receptor (ER) and progesterone receptor (PgR) levels were measured by the dextran-coated charcoal method in the cytosol of neoplastic tissue. MUC3 was expressed in 43/44 serum samples while high MCA serum levels were found in 16/44 only; the mean values of both markers did not correlate with menopausal status, tumor size, nodal involvement or ER. The only significant difference observed was a lower median value of MCA in patients with small tumors (T1-T2). No statistically significant correlation between MUC3 and MCA, MUC3 and ER or MCA and ER was observed; a statistically significant direct correlation between MUC3 and PgR+ status and a statistically significant inverse correlation between MCA and PgR+ were observed. Our results suggest that further investigations are necessary to establish whether progesterone can modulate MUC3 and MCA expression in breast cancer.     

Steroid receptors in the developing and the adult rabbit endocervix and in endocervical epithelial cells isolated by flow cytometry

Immunocytochemistry with monoclonal antibodies H222 and JZB39 was used to study nuclear estrogen (ER) and progesterone (PgR) receptors, respectively, in the cervix during differentiation and in the adult rabbit. The undifferentiated state of the cervix of 2-week-old rabbits correlates with a paucity of immunoreactive nuclear ER, while the epithelium of most of these animals showed moderate immunostaining for the nuclear PgR. The cervical epithelium, stroma and muscle cells of 1-month-old rabbits, showed weak immunostaining for the ER, while staining for PgR remained comparable to that of 2-week-old rabbits. For 2-4-month old rabbits the epithelium was characterized by moderate immunostaining for the nuclear ER and strong immunostaining for the PgR. Strong, heterogeneous immunostaining for nuclear ER and PgR receptors in endocervical epithelial cells from 6-month-old (adult), estrous rabbits suggested there are subpopulations of cells that express differential sensitivity to steroid hormones. In order to characterize such subpopulations, live endocervical epithelial cells were sorted with a flow cytometer on the basis of forward angle light scatter (FSC) and side scatter (SSC) signals which correlated with cell size and secretory granule content, respectively. Secretory cells, as verified by ultrastructural analysis and histochemical staining, expressed the highest FSC and SSC signals and were designated fraction "a". Changes in the hormonal status of the animals altered the intrinsic light scatter properties of fraction "a" cells as follows: maximum FSC and SSC signals were reported for cells from estrous animals; ovariectomy or progesterone-dominance decreased cell size (FCS) and secretory granule content (SSC), while treatment of ovariectomized rabbits with estradiol increased both parameters. When fraction "a" cells from estrous rabbits were incubated with the monoclonal antibodies, two distinct subpopulations of secretory cells were identified by intensity and pattern of nuclear staining for the ER and PgR. Changes in the hormonal status of the animals produced changes in the intensity of nuclear immunostaining, however both cell types remained distinguishable on the basis of immunostain pattern reflecting either permanent or transitory differences in them, and differential hormone sensitivity. The presence of nuclear ER and PgR proteins in these cells confirms their function is bireceptor-mediated.     

Flow cytometric analysis of estrogen, progesterone receptor expression and DNA content in formalin-fixed, paraffin-embedded human breast tumors.

Flow cytometric analysis of estrogen (ER) and progesterone (PgR) receptor expression in archival human breast tumors is relatively difficult. We have used enzyme digestion and microwave antigen retrieval procedures for multiparametric flow cytometric analysis of ER and PgR expression and DNA content in nuclei isolated from formalin-fixed/paraffin-embedded primary breast tumors. Deparaffinized rehydrated tissue sections treated with pepsin were subjected to microwave irradiation for unmasking of ER and PgR antigenic sites. Biotinylated ER antibody and streptavidin-fluorescein isothiocyanate (FITC) were used for ER labeling and PgR antibody with phycoerythrin labeled goat anti-mouse antibody was used for PgR labeling. Counter staining with propidium iodide-RNase was used for determination of cellular DNA content. Our results show that enzyme digestion and microwave treatment of formalin-fixed, paraffin-embedded breast tumors can be successfully used for the multiparametric analysis of nuclear hormone receptor expression and DNA content by flow cytometry.     

Estrogen- and progesterone receptors in normal cycling endometrium as studied by end-point titration

A thorough knowledge of the normal physiological fluctuations in estrogen-(ER) and progesterone receptors (PgR) is essential to characterize the changes in ER and PgR in the abnormal endometrium. We investigated the distribution of ER and PgR in frozen human cycling endometrial tissue using the commercially available ER-and PgR-ICA kits. Two-fold end-point titration (EPT) of ER and PgR antibodies was implemented to semi-quantitate more accurately ER and PgR. Semiquantitation of ER and PgR using EPT was significantly correlated to results obtained using either simple scoring or enzyme-immunoassay (EIA) methods. ER and PgR staining fluctuated in relation to the menstrual cycle. In most subphases PgR exceeded ER in both epithelial and stromal cells. Highest levels of ER and PgR were demonstrated in the glands of the functionalis in mid-to-late proliferative phases, whereas both receptors were almost undetectable by immunohistology in the glands of mid-to-late secretory phases. Endometrial stromal cells had high and nearly constant EPT values for PgR, but low values for ER througout the menstrual cycle. EPT values for ER and PgR were generally higher in the basalis than in the functionalis but showed similar cyclic fluctuations. Our results further substantiate the view that the response to hormonal stimulation is cell-type specific, and suggest differences in steroid metabolism according to cell type and layer.     

Use of an enzymeimmunoassay (EIA) for quantitation of cytosolic and nuclear estrogen receptor, and correlation with progesterone receptor in human breast cancer

We have adapted a commercially available enzyme immunoassay for ER (ER-EIA) for use with nuclear extracts of breast carcinoma specimens, and have examined the data obtained in relation to the results from cytosolic ER-EIA and radioligand (DCC) assays and from DCC assays for PgR. In a series of 139 carcinoma specimens, we observed a very significant correlation between the cytosolic ER concentration as measured by the EIA and DCC methods, and also between the log10 of the concentration of ER in the cytosolic and nuclear fractions assayed by the ER-EIA method. The correlation between nuclear ER and cytosolic PgR was also highly significant, but not as close as for cytosolic ER. If 130 fmol ER/mg DNA was used as a "cut-off" point to discriminate between specimens "positive" and "negative" for ERN, there was 87% concordance in receptor status between ERN and cytosolic ER, and 79% concordance between ERN and cytosolic PgR. Forty-one percent of specimens were positive or borderline for both ERN and cytosolic PgR, and it is suggested that this receptor combination may be a valuable predictive factor in prognosis and response to hormonal treatment.     

Gene-specific patterns of coregulator requirements by estrogen receptor-α in breast cancer cells

Progesterone receptor (PgR) controls the menstrual cycle, pregnancy, embryonic development, and homeostasis, and it plays important roles in breast cancer development and progression. However, the requirement of coregulators for estrogen-induced expression of the PgR gene has not been fully explored. Here we used RNA interference to demonstrate dramatic differences in requirements of 10 different coregulators for estrogen-regulated expression of six different genes, including PgR and the well-studied TFF1 (or pS2) gene in MCF-7 breast cancer cells. Full estrogen-induced expression of TFF1 required all ten coregulators, but PgR induction required only four of the 10 coregulators. Chromatin immunoprecipitation studies demonstrated several mechanisms responsible for the differential coregulator requirements. Actin-binding coregulator Flightless-I, required for TFF1 expression and recruited to that gene by estrogen receptor-α (ERα), is not required for PgR expression and not recruited to that gene. Protein acetyltransferase tat-interactive protein 60 and ATP-dependent chromatin remodeler Brahma Related Gene 1 are recruited to both genes but are required only for TFF1 expression. Histone methyltransferase G9a is recruited to both genes and required for estrogen-induced expression of TFF1 but negatively regulates estrogen-induced expression of PgR. In contrast, histone methyltransferase myeloid/lymphoid or mixed-lineage leukemia 1 (MLL1), pioneer factor Forkhead box A1, and p160 coregulator steroid receptor coactivator-3 are required for expression of and are recruited to both genes. Depletion of MLL1 decreased ERα binding to the PgR and TFF1 genes. In contrast, depletion of G9a enhanced ERα binding to the PgR gene but had no effect on ERα binding to the TFF1 gene. These studies suggest that differential promoter architecture is responsible for promoter-specific mechanisms of gene regulation.     

Kinetics of cellular proliferation and hormonal receptors in EVSA-T breast cancer cell line.

The hormone-independent human breast cancer cell line EVSA-T, originally described as negative estrogen and progesterone receptors is shown to become positive hormone receptors when the cellular proliferation rate is slowed down. The experimental procedure included the following steps: 1) EVSA-T cells were seeded in minimum essential medium supplemented with 10% fetal bovine serum and kept undisturbed for 2 days; 2) culture medium was replaced with Dulbecco's solution and Ham's F-12 and cells were incubated in serum-free media for another 24 h; 3) then, cells were "rescued" with 10% FBS supplemented medium and estrogen (ER) and progesterone receptors (PgR) were measured immediately, time 0, and 6, 12, 18, 24 and 30 h after the media were changed. Cell yield was quantified at the same times. Experimental data indicate that changing the proliferation kinetics makes it possible to detect estradiol and progesterone receptors on EVSA-T cells. Estrogen receptor appeared at 18 h after rescue, 6 hours before progesterone receptor could be detected. Immunohistochemical analysis of ER content confirmed this observation, showing maximal positive stain at 18 h. Furthermore, ER disappeared when cells recovered their normal proliferation rate.     

Comparison of the oestrogen and progesterone receptor status in primary breast carcinomas as evaluated by immunohistochemistry and immunocytochemistry: a consecutive series of 267 patients

A.M. Domanski, N. Monsef, H.A. Domanski, D. Grabau and M. Fernö
Comparison of the oestrogen and progesterone receptor status in primary breast carcinomas as evaluated by immunohistochemistry and immunocytochemistry: a consecutive series of 267 patients Objective: The use of cytological specimens to evaluate tumour biomarkers in metastatic breast cancer lesions has attracted increased interest because of the considerable number of reports that have shown discordance between the primary tumour and metastatic lesion. Oestrogen receptor (ER) and progesterone receptor (PgR) assays are crucial for the management of patients with breast cancer, in both adjuvant and palliative settings. The aim of this study was to compare the ER and PgR immunocytochemical analysis of fine needle aspiration (FNA) samples with the immunohistochemistry (IHC) of surgical specimens and core biopsies from primary breast cancers. Methods: The FNA specimens were prepared as cell blocks (n = 25) or ThinPreps (n = 258) for the immunocytochemistry (IC) ER and PgR analyses. Sixteen patients were excluded because of lack of follow‐up (n = 1), neoadjuvant therapy (n = 3) or cell counts in their fine needle aspirates that were too low (n = 12). The results of IC on 25 cell blocks and 242 ThinPreps were compared with IHC on the corresponding core needle biopsies (n = 16) or excised tumours (n = 251). The ER and PgR status was defined as negative (when less than 10% of the nuclei were stained) or positive (when equal or more than 10% of the nuclei were stained). Kappa statistics were used to evaluate the concordance. Results: The ER concordance was 98% with ThinPrep (κ = 0.93) and 92% with cell block (κ = 0.82). The corresponding values for PgR were 96% (κ = 0.91) and 96% (κ = 0.92). Conclusions: Our results confirm that, in cases in which biopsies or surgical specimens are not available, IC (with either cell block or ThinPrep techniques) is a reliable method for the determination of the ER and PgR status performed under strict conditions using primary breast carcinomas, and is therefore potentially useful in metastatic settings.     

Clinicopathologic Characteristics of Oestrogen Receptor-Positive/Progesterone Receptor-Negative/Her2-Negative Breast Cancer According to a Novel Definition of Negative Progesterone Receptor Status: A Large Population-Based Study from China

PurposeA lack of progesterone receptor (PgR) expression in oestrogen receptor-positive (ER+) tumours is associated with worse survival. PgR status is usually defined as positive or negative using 1% positive nuclei as a cut-off point. In this study, we aimed to assess the clinicopathologic characteristics of ER+/PgR-/HER2- tumours by comparing them with ER+/PgR+/HER2- tumours using a PgR cut-off point of 20% as a divisive criterion.MethodsWe analysed 1,522 patients with primary breast cancer who had undergone surgery at the Cancer Center of Fudan University between 2012 and 2014. Age, grade, tumour size, lymph node status and lymphovascular invasion were assessed. Multinomial logistic regression, linear regression and chi-square test models were applied to assess associations between ER, PR and clinical features.ResultsER+/PgR-/HER2- tumours showed poorer clinicopathologic characteristics relative to ER+/PgR+/HER2- tumours using a PgR threshold of 20% instead of 1%. The clinicopathologic characteristics did not differ between tumours with purely negative PgR expression and tumours with a PgR percentage ranging from 1% to 19%. The prognostic significance of PR expression appeared more pronounced in patients under a high Ki-67 status than those under a low Ki-67 status.ConclusionsBased on these findings, we propose the use of a novel threshold of 20% to define PgR status. Nevertheless, the impact of this new criterion on patient management and clinical treatment requires additional study.     

Autocrine regulation of rheumatoid arthritis synovial cell growth in vitro

Rheumatoid arthritis (RA), and not osteoarthritis (OA) synovial cells proliferate in serum-free medium, a finding that suggests that, in vitro, RA synovial cells may be stimulated to grow by the continuous autocrine production of at least one polypeptide growth factor. Adding monoclonal antibody 1D11.16, or rabbit polyclonal anti-tumor growth factor beta (anti-TGF-beta) antibodies (both neutralizing antibodies to TGF-beta 1 and TGF-beta 2) to RA synovial cells, in culture, caused a significant reduction in cell growth, an effect not seen when other growth factor antibodies (platelet-derived growth factor [PDGF], epidermal growth factor [EGF], or EGF receptor) were added to the culture medium. Taken together, these data are consistent with the concept that RA synovial cell growth in vitro is driven endogenous TGF-beta. Moreover, when EGF was added to the culture medium, this caused the numbers of RA, and not OA, synovial cells to increase significantly. This finding suggests that RA synovial cells are in G1 phase of the cell cycle; an effect that could be mediated by endogenous TGF-beta.     

Relationship between steroid receptors (as continuous variables) and response to adjuvant treatments in postmenopausal women with node-positive breast cancer.

In current clinical practice for breast cancer patients, estrogen (ER) and progesterone receptor (PgR) concentrations, quantified by the dextran-coated charcoal assay, are categorized by an arbitrary cutoff into a negative or positive status. However, although the results obtained with this approach are easy to interpret, such a representation could oversimplify the relationship between ER and PgR content and patient outcome and imply an assumption of monotonicity, which is generally expected but rarely proven. We evaluated the relationship between ER and PgR content (considered on a continuous scale) and clinical outcome, using a flexible statistical model, in a group of postmenopausal patients with N-positive operable tumors who were submitted to surgery and different adjuvant treatments (tamoxifen or CMF). Univariate analysis indicated that in the tamoxifen-treated group, ER level, number of metastatic nodes (pN) and age, but not PgR, were significant indicators of clinical outcome (p = 0.032, p = 0.021 and p = 0.029, respectively). Multivariate analysis indicated that in this group of patients there was no interaction between variables, and in the final model for disease-free survival (DFS) only ER and pN were retained with an overall predictive ability of the regression model of 0.723, as evaluated by Harrell's c. However, pN markedly contributed to the predictive ability of the model with respect to ER, since a marked decrease in Harrell's c statistic (c = 0.582) was observed when pN was removed from the model. In the CMF-treated group, only pN affected clinical outcome. When the estimated DFS curves obtained from the final Cox regression models were plotted according to four values of ER (in the tamoxifen-treated group) or three values of pN (in the CMF-treated group) we observed that in the tamoxifen-treated group patients with an ER concentration equal to 0 fmol/mg cytosol protein had the worst prognosis, whereas a marked improvement of the expected DFS was observed for patients with a low but detectable ER level (generally classified as ER-negative because falling below the conventional cutoff value of 10 fmol/mg cytosol protein). Our results seem to suggest that the use of steroid receptor concentrations on a continuous scale, instead of dichotomous "status", is to be preferred in the choice of adequate therapeutic strategies.     

Demonstration of estrogen receptors and of estrogen responsiveness in the HKT-1097 cell line derived from diethylstilbestrol-induced kidney tumors

Summary This study was undertaken in order to examine the estrogen sensitivity of HKT-1097, an established cell line recently derived from diethylstilbestrol (DES)-induced kidney tumors in Syrian hamsters. Estrogen receptor (ER) level in HKT-1097, determined by enzyme-linked immunoassay, was 67 fmol/mg protein, i.e., a value approx. 30% lower than that found in Syrian hamster kidney tumors. ER immunostaining in cells fixed with Carnoy's mixture, as well as ER demonstration by Western blotting, suggested DES-induced nuclear translocation or stabilization of the receptor within the nucleus. Kinetic parameters of estrogen binding to ER in HKT-1097 cells were 8.4×10⁻¹¹ M and 60.8 fmol/mg protein for K _d and B_max, respectively. The K _d of estrogen binding to ER in HKT-1097 was close to that evaluated for the receptor in breast cancer-derived MCF-7 cell line, whereas the B_max value was approx. seven times lower in HKT-1097 as compared to MCF-7. In HKT-1097 cells, antiestrogens ICI 182,780 and RU 58,668 induced ER downregulation and competed with estrogen binding to the receptor. As demonstrated by Western blot analysis, DES exposure led to an increased expression of progesterone receptor (PgR) in HKT-1097 cells. Addition of DES to estrogen-free medium produced a stimulation of growth in both HKT-1097 and MCF-7 cells, but the mitogenic effect was less marked for HKT-1097. Despite the fact that ICI 182,780 and RU 58,668 clearly interact with HKT-1097 cell ER, they appeared unable to suppress DES-induced stimulation of growth and increase of PgR expression.     

Plasminogen activators in human breast cancer cell lines: hormonal regulation and properties

To understand the hormonal regulation of plasminogen activators (PAs) in human breast cancer, we have examined the hormonal regulation and properties of PAs in four human breast cancer cell lines that differ markedly in their estrogen receptor (ER) content: MCF-7 cells contain high levels of ER (approx 7 pmol/mg DNA) and their PA activity was increased 3-4-fold by physiological concentrations of estradiol; T47-D and ZR-75-1 cells contain lower levels of ER (0.9 and 2.1 pmol/mg DNA respectively) and their PA activity was also increased 3-4-fold by estradiol. In contrast, MDA-MB-231 cells, which do not contain ER, showed a high level of PA activity that was not modulated by estradiol. SDS-PAGE followed by zymography indicated that MCF-7 cells secreted tissue-type PA (t-PA), T47-D and ZR-75-1 cells secreted urokinase-type PA (u-PA), and MDA-MB-231 cells secreted both types of PAs. The types of PAs secreted by these cell lines did not change upon treatment with estradiol. Dose-response curves for the stimulation of MCF-7 PA activity by different estrogens showed an excellent correlation between affinities of the estrogens for ER and their potency in stimulating PA activity. With a clonal subline of MCF-7 cells, MCF-L, a soluble inhibitor of both t-PA and u-PA was secreted. Incubation of purified t-PA or u-PA with the serum-free conditioned medium from MCF-L cells resulted in a shift in the mobility of t-PA and u-PA in SDS-polyacrylamide gels to forms increased in molecular mass by about 50,000-70,000. The shifts in molecular mass could be prevented by the presence of the competitive inhibitor p-aminobenzamidine, indicating that the active sites of the PAs were involved in the formation of these complexes. Furthermore, co-cultivation, of RT4-D rat neuroblastoma cells, which exhibit high levels of t-PA activity, with MCF-L cells resulted in a marked decrease in the PA activity of the RT4-D cells. Our results were consistent with the following conclusions: t-PA, u-PA or both were secreted by human breast cancer cells. In the ER-containing cell lines, depending upon the specific cell line, t-PA or u-PA was stimulated by estrogens. The unstimulated levels of PA activity and the magnitude of PA stimulation by estrogens were not closely related to ER content.(ABSTRACT TRUNCATED AT 400 WORDS)     

Is preoperative core biopsy accurate in determining the hormone receptor status in women with invasive breast cancer?

Background

The objective of this study was to determine the concordance rate between core needle biopsy (CNB) and surgical excision of invasive breast cancer regarding the oestrogen receptor (ER) and Progesterone receptor (PgR) status as determined by Immunohistochemistry (IHC).

Methods

Hormone receptor status was established using IHC (using quickscore system 0–8) on preoperative CNB and subsequent surgical excision in 93 patients with invasive breast cancer. Results were compared taking into account tumour's size, grade, and patient's age.

Results

The ER concordance rate between CNB and surgical excisions was 95%. The PgR concordance rate was 89%. This shows that CNB has a sensitivity of 97% for ER and 95% for PgR.There is a positive correlation of ER and PgR between CNB and surgical excision (p < 0.000001). There was no significant difference in the number of core biopsies between concordant and discordant cases.

Conclusion

Preoperative core biopsy is highly sensitive for the IHC detection of ER and PgR in invasive breast cancer. The concordance rate is higher for ER than PgR, which could be due to the fact that ER is more homogeneously distributed.

     

Patterns of estrogen and progesterone receptors in rhesus monkey endometrium during secretory phase of normal menstrual cycle and preimplantation stages of gestation

Using validated methods, estradiol receptor (ER) and progesterone receptor (PgR) levels have been estimated in endometria collected in secretory phase of normal menstrual cycle and preimplantation stages of gestation from rhesus monkeys (Macaca mulatta). Endometrial PgR in both cytoplasmic and nuclear compartments decreased significantly (P less than 0.001) from day 2 to day 6 post-ovulation in both groups, but in fertile cycle, absolute levels of nuclear PgR remained significantly higher (P less than 0.05) on days 4, 5 and 6 of gestation, ER concentrations, both total (P less than 0.02), as well as cytoplasmic (P less than 0.01) declined significantly in secretory phase of normal menstrual cycle while nuclear ER levels remained unchanged. In the preimplantation period, ER patterns remained unvarying on days 2-6 of gestation in both cytoplasmic and nuclear compartments; their levels in nuclear fraction were significantly higher from day 3 onwards while, total cytoplasmic ER concentrations were higher from day 4 of gestation compared with the values obtained for secretory phase tissues from normal ovulatory cycles. No changes were, however, detected in apparent equilibrium dissociation constants (Kd) for the sex steroid receptors in endometria obtained from fertile and non-fertile cycles. It has been suggested that in prenidatory stage rhesus monkey endometrium elevated concentrations of nuclear ER and PgR possibly indicate higher degree of nuclear occupancy required for endometrial differentiation permitting blastocyst implantation.     

Antitumor effects of combination toremifene and medroxyprogesterone acetate (MPA) in vitro and in vivo

The estrogen (ER) and progesterone (PgR) receptor levels in various gynecological tumors were measured. The same tumors were exposed in vitro to toremifene, MPA or their combination and the growth of the tumors was followed by measuring the adenosine triphosphate (ATP) within the cells by a simple bioluminescence assay. Altogether 34 clinical samples were studied. DMBA-induced mammary tumors bearing rats were treated in vivo with toremifene, MPA and their combination. About half of the ovarian cancers and 6 out of the 7 adenocarcinomas of uteri contained ER. The ovarian tumors were PgR rich in 25% and adenocarcinomas of uteri in 6 out of the 7 cases. When compared to control toremifene (concentration 1 mumol/l) was able to decrease the number of living cells to 50% or less in 9/34 samples, MPA (concentration 10 mumol/l) in 17/34 samples, and the combination in 25/34 samples. In five cases the antitumor effect of the combination was synergistic. In two cases signs of weak antagonism were seen. In vivo the antitumor effect of toremifene and MPA was clearly synergistic against DMBA-induced cancers. The effect was dose-dependent and at sufficiently high doses it was possible to eradicate the tumors and cure the animals.     

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

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