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Very young women (<35 years) with operable breast cancer: features of disease at presentation.

BACKGROUND: Breast cancer rarely occurs in young women. Our knowledge about disease presentation, prognosis and treatment effects are largely dependent upon older series. MATERIALS AND METHODS: We evaluated biological features and stage at presentation for 1427 consecutive premenopausal patients aged < or = 50 years with first diagnosis of invasive breast cancer referred to surgery at the European Institute of Oncology from April 1997 to August 2000. A total of 185 patients (13%) were aged < 35 years ('very young') and 1242 (87%) were aged 35-50 years ('less young'). The expression of estrogen receptors (ER), progesterone receptors (PgR), presence of vascular invasion (VI), grading (G), expression of Ki-67, HER2/neu overexpression, pathological stage according to TNM staging system (pTNM), pathological tumor size and number of axillary lymph node involvement were evaluated. RESULTS: Compared with less young patients, the very young patient group had a higher percentage of tumors classified as ER negative (P < 0.001), PgR negative (P = 0.001), higher expression of Ki-67 > or = 20% of cells stained; 62.2% versus 53%, (P < 0.001), vascular or lymphatic invasion (48.6% versus 37.3%, P = 0.006), and pathological grade 3 (P < 0.0001). There was no difference between the two groups for pT, pathological tumor size (pN) and number of positive lymph nodes. CONCLUSIONS: We conclude that compared with less young premenopausal patients, very young women have a greater chance of having an endocrine-unresponsive tumor, and are more likely to present with a higher grade, more extensively proliferating and vessel invading disease. Pathological tumor size, nodal status and number of positive axillary lymph-nodes have a similar distribution among the younger and the older cohorts, thus not supporting previous data indicating more advanced disease in younger patients at diagnosis of operable disease.

Adult↗

PCNA/cyclin expression in breast carcinomas: its relationships with Ki-67, ER, PgR immunostainings and clinico-pathologic aspects.

By the monoclonal antibody PC10, the Authors have analyzed the proliferating cell nuclear antigen (PCNA) immunoreactivity on fixed and unfixed specimens of breast ductal (42 cases) and lobular carcinomas (15 cases) as well as in normal breast tissue adjacent to carcinomas; for all cases the post-surgical staging as well as immunohistochemical data concerning ER and PgR receptors were available. In addition, the immunohistochemical pattern of Ki-67 has been also recorded. The study documented a constant expression of PCNA in all breast carcinomas with an heterogeneous pattern whereas the immunoreactivity for Ki-67 appeared less represented and focal, so that a linear relationship between PCNA and Ki-67 immunostaining was absent. Moreover, the chi-square test failed to show any correlation between PCNA and immunocytochemical demonstration of ER and PgR receptors, dimensions of tumours, histological grade and lymph node involvement. The PCNA expression in adjacent morphologically normal breast tissue may suggest an accumulation of cyclin without a necessary induction of DNA synthesis.

Adult↗

Comparison of the results of immunocytochemical assays for biologic variables on preoperative fine-needle aspirates and on surgical specimens of primary breast carcinomas.

BACKGROUND: Fine-needle aspiration biopsy (FNAB) is a well-documented procedure for the diagnosis and biologic characterization of breast carcinoma. In order to compare the immunocytochemical expression of biologic parameters on cytology and on histology, estrogen receptor (ER) and progesterone receptor (PgR) status, p53 protein expression, and Ki67 growth fraction were evaluated on presurgical fine-needle aspirates (FNAs) from breast carcinoma patients and on the corresponding surgical samples prior to any systemic therapy. METHODS: FNAs were performed on 104 patients with primary breast carcinoma at the time of diagnosis and subjected to immunocytochemical evaluation of ER, PgR, p53, and Ki67. The same parameters were immunohistochemically evaluated on the corresponding paraffin embedded sections. RESULTS: ER, PgR, p53, and Ki67 were evaluable on FNAs and on paired tissue sections in 100, 97, 68, and 84 cases, respectively. Concordance between cytology and histology was 89% for ER, 78% for PgR, 79% for p53, and 70% for Ki67. CONCLUSIONS: The concordance between the results of immunocytochemical evaluation of ER, PgR, p53, and Ki67, on both cytology and histology, underscores the reliability of the biologic characterization of breast carcinoma by FNAB. This approach could be particularly useful in predicting prognosis and response to treatment in patients who are candidates for neoadjuvant chemotherapy and/or endocrine therapy.

Biomarkers↗

Relationship between hormone receptor levels and cell-kinetics in human colorectal cancer.

BACKGROUND: This study was done to determine the potential role of sex steroid hormone receptors in the development of human colorectal cancer. METHOD: Receptors for estrogen (ER) and progesterone(PgR) were investigated in surgical specimens from 22 patients with colorectal cancer, using enzyme immunoassay. These values were examined in relation to cell kinetics parameters determined by DNA flow cytometry. RESULTS: ER and PgR were detected in 27% and 41%, respectively. There were no significant differences in the expression of ER or PgR according to the age, sex of the patients, tumor size, location, histological differentiation and lymph node metastasis. Although ER status appeared to be independent of DNA parameters, there were better correlations of PgR-negative tumors with increased hyperaneuploid levels. There were significantly higher values of heterogeneity index score in PgR-negative tumors compared with PgR-positive tumors. In the multiple regression analysis, PgR levels proved to be a major independent factor for changes in DNA index and heterogeneity index score. CONCLUSION: The PgR status is a critical factor for determining the proliferative activity of colorectal cancer tissue and may play a biological role in regulating the growth of the tumor.

Adenocarcinoma↗

Hormone receptor status and HER2/neu overexpression determined by automated immunostainer on routinely fixed cytologic specimens from breast carcinoma: correlation with histologic sections determinations and diagnostic pitfalls.

Although fine-needle aspiration cytology is a routine procedure for the diagnosis of breast carcinoma, cytologic specimens have rarely been used for evaluation of hormone receptor status and HER2/neu overexpression. In order to compare the biological markers on cytology and on histology, routinely fixed smears of 110 primary breast carcinomas were immunostained for estrogen receptor (ER), progesterone receptor (PgR), and HER2/neu by automated immunostainer and the results were compared with the corresponding histologic sections. ER was expressed in 76 of 110 (69%) cases and PgR was expressed in 51 of 110 (46%). Overexpression of HER2/neu was observed in 30 of 110 (27%) cases. Concordance between cytology and histology was 98% for ER, 95% for PgR, and 100% for HER2/neu. There was no false positive result on smears. Diagnostic pitfalls in determination of hormone receptor status on smears included intratumoral heterogeneity and presence of mucin.

Adult↗

Unsupervised proteome analysis of human leukaemia cells identifies the Valosin-containing protein as a putative marker for glucocorticoid resistance.

The response to initial glucocorticoid therapy in childhood acute lymphoblastic leukaemia (ALL) reliably predicts the response to multiagent chemotherapy. Patients resistant to glucocorticoids (prednisone poor responders (PPR)) have a poorer event-free survival compared to glucocorticoid-sensitive patients (prednisone good responders (PGR)). A case-control study was performed to investigate differential protein expression in leukaemic blasts from PGR and PPR childhood ALL patients. Two-dimensional gel electrophoresis (2-DE) was used for an unsupervised screening and surface enhanced laser desorption/ionisation-time of flight mass spectrometry (SELDI-TOF MS) for the characterisation of protein spots. In difference maps of average gels for the proteomes of each responder group, differentially expressed proteins were identified after tryptic digestion and spotting onto H4-SELDI-TOF-MS chips. Proteins overexpressed in PPR were Catalase, RING finger protein 22 alpha, Valosin-containing protein (VCP) and a G-protein-coupled receptor. Proteins overexpressed in PGR were protein kinase C and malate dehydrogenase. Valosin-containing protein was chosen for validation and quantification by Western blot analysis in a second case-control group of ALL patients. In this second independent cohort, median VCP expression (P25-P75) was 0.15 (0.11-0.28) in PGR and 0.34 (0.14-0.99) in PPR patients (P = 0.04). We conclude that high VCP expression is associated with poor prednisone response in childhood ALL patients.

Adenosine Triphosphatases↗

Expression of oestrogen and progesterone receptors, Ki-67, p53 and BCL-2 proteins, cathepsin D, urokinase plasminogen activator and urokinase plasminogen activator-receptors in carcinomas of the female breast in an African population.

OBJECTIVE: To determine the expression of oestrogen (ER) and progesterone receptor (PgR), Ki-67, p53, bcl-2 proteins and the proteolytic enzymes cathepsin D (CD), urokinase-plasminogen activator (uPA) and its receptor (uPA-R) in primary carcinomas of the breast from indigenous Tanzanian female patients by immunohistochemistry. DESIGN: Prospective cross-sectional study. SETTING: Muhimbili Medical Centre, Dar es Salaam, Tanzania. SUBJECTS: Sixty patients admitted between 1995 and 1997. RESULTS: Markers were found to be expressed as follows: ER (33.3%), PgR (18.3%), p53 (30%), bcl-2 (43.5%) and the median proliferation rate of Ki-67 was 15%. Proportion of tumours positive for ER, PgR and bcl-2 initially decreased to 12 months disease duration, after which it increased. The observed proliferation rate approaches that reported in developed countries. p53 expression did not influence the proliferation rate nor did bcl-2 expression. ER, PgR and bcl-2 were strongly co-expressed. CD was predominantly expressed in stromal macrophages than in cancer cells. CONCLUSION: The low expression of ER and PgR and their strong co-expression with bcl-2 might negatively influence response to hormonal therapy. The influence of bcl-2 on tumour response to anti-cancer therapy in patients with long disease duration requires urgent clarification. Determination of CD in stromal macrophages rather than in cancer cells may have greater prognostic significance in patients of this region.

Breast Neoplasms↗

In vitro effects of tamoxifen on UM-SCC head and neck cancer cell lines: correlation with the estrogen and progesterone receptor content.

Eleven squamous-cell carcinoma (SCC) cell lines derived from patients with head and neck cancer were tested together with the MCF-7 breast carcinoma cell line for in vitro growth inhibition by tamoxifen. MCF-7 is known to contain cytosolic receptors for estrogen (ER), progesterone (PgR), androgen (AR) and glucocorticoid. We have previously reported the ER, PgR and AR contents of these 11 head-and-neck SCC cancer lines. Starting from day 3 or 4 after passage, cultures were fed daily with medium containing 5% dextran-charcoal-treated fetal bovine serum (D5) and 0, 1, 2.5, 5, 7.5 or 10 microM tamoxifen. Eight of the 11 SCC lines and MCF-7 showed more than 60% growth inhibition when fed with 5 microM tamoxifen. Of these 8 SCC cell lines, 3 contained both ER and PgR, 4 contained only PgR, and one contained neither receptor. The 3 cell lines that were not inhibited by tamoxifen failed to express either ER or PgR. The action of tamoxifen on the cell lines was further investigated by examining the reversibility and the rate of recovery from tamoxifen-induced growth inhibition in the presence or absence of estrogen. MCF-7 and two ER- and PgR-positive SCC cell lines, UM-SCC-12 and UM-SCC-9, recovered more rapidly when the tamoxifen was replaced with medium containing 17-beta estradiol (E2) than when it was replaced with D5 medium alone. However, of the other tamoxifen-inhibited cell lines studied, each recovered equally well whether the tamoxifen was replaced with D5 medium or with D5 medium containing E2. Furthermore, some cell lines spontaneously resumed growth within 4 to 5 days in the presence of tamoxifen if no new tamoxifen was added to the culture dish. This ability is specific for some cell lines, and further study is required to determine its significance.

Carcinoma, Squamous Cell↗

Mutations and amplification of oncogenes in endometrial cancer.

Alterations in oncogenes are critical steps in the development of endometrial cancer. To investigate the potential clinical relevance of the amplification of the oncogenes c-erbB2, c-myc, and int-2 and the mutation of K-ras in endometrial cancer, 112 tumors were examined using PCR-based fluorescent DNA technology. Amplification of the three oncogenes and the mutation of K-ras were correlated with age, tumor size, lymph node status, metastases, stage, histological types, grade, steroid hormone receptor expression (estrogen receptor, ER; progesterone receptor, PgR), family history of cancer, previous history of cancer or precursor lesions, and previous history of hormone replacement therapy. Oncogene amplification of c-erbB2 was detected in 18.9%, of c-myc in 2.7% and of int-2 in 4.2%, and K-ras mutation in 11.6%. No significant correlations could be detected between amplification of c-erbB2 and any of the other parameters. Mutation of K-ras is associated with positive expression of PgR. This might indicate that mutation and activation of K-ras are involved in the development of hormonal independence in endometrial cancer.

DNA Primers↗

Estrogen responsiveness of IBEP-2, a new human cell line derived from breast carcinoma.

IBEP-2, an established cell line recently derived from breast carcinoma, was characterized with regard to estrogen receptor (ER) expression, cell mitogenic response to estrogenic stimulation and sensitivity to antiestrogens. In addition, we examined ER modulation following binding of agonist and antagonists, and the ER-mediated induction of progesterone receptor (PgR). ER level in IBEP-2 cells, determined by enzyme-linked immunoassay (EIA), was slightly higher than that measured in MCF-7 cells (662 v.s. 595 fmol/mg protein). When tested on IBEP-2 and MCF-7, various agonists stimulated cell growth with EC50's reflecting different estrogenic potencies (E(2) approximately diethylstilbestrol > E(1) > genistein). IBEP-2 appeared slightly more sensitive than MCF-7, especially to E(2) (at least 4-fold difference between EC50 values). By contrast, IBEP-2 and MCF-7 were equally sensitive to the growth inhibitory effect of antiestrogens 4-hydroxy-tamoxifen (OH-Tam) and ICI 182,780. As revealed by immunoblotting and immunofluorescence using anti-ER alpha antibodies, ER expression in IBEP-2 cells was modulated by E(2) and estrogen antagonists like it has been shown in other ER-positive cell lines, that is, E(2) and ICI 182,780 caused ER downregulation, whereas OH-Tam induced ER accumulation. Ligand-induced downregulation of ER involved degradation in proteasomes, since it was suppressed by the proteasome inhibitor MG-132. Exposure of IBEP-2 cells to E(2) resulted in a marked (at least 25-fold) induction of PgR, documented by EIA, immunoblotting and immunofluorescence. PgR induction due to E(2) was not modified by MG-132. Interestingly, MG-132 alone produced an ER-independent increase of PgR expression. IBEP-2 might prove to be valuable to study ER-mediated induction of PgR.

Breast Neoplasms↗

In vitro growth and ovulation of follicles from ovaries of estrogen receptor (ER){alpha} and ER{beta} null mice indicate a role for ER{beta} in follicular maturation.

Both estrogen receptor (ER) alpha and beta are expressed within the ovary and lack of either of these receptors affects ovarian function. In this study, the role of ERalpha and ERbeta in folliculogenesis and ovulation was further analyzed. Evaluation of ovarian follicle populations in wild-type and ERbeta knockout (betaERKO) ovaries revealed reduced late antral growth and ovulatory capacity of betaERKO follicles, indicated by reduced numbers of large antral follicles and corpora lutea and increased atresia of large antral follicles. An in vitro culture system was used to study growth, rupture, and luteinization of wild-type, ERalpha knockout (alphaERKO) and betaERKO ovarian follicles. alphaERKO follicles exhibited wild-type-like growth and ovulation rates but an increased capacity to synthesize estradiol. In contrast, betaERKO follicles showed a significant lack of progression from early antral to large antral stage, decreased estradiol production, and reduced ovulation. Expression patterns of several genes involved in follicle maturation and ovulation were analyzed in follicles grown in vitro. Ar, Pgr, and Has2 mRNA expression levels were the same among the three genotypes. However, betaERKO follicles showed reduced expression of Cyp19 mRNA during follicle maturation and reduced Lhcgr and Ptgs2 mRNA expression after human chorionic gonadotropin stimulus. Luteinization occurs normally in alphaERKO and betaERKO follicles, shown by increased progesterone secretion and increased cdkn1b mRNA expression after human chorionic gonadotropin. Collectively, these data indicate that ERbeta, but not ERalpha, plays a direct role in folliculogenesis. ERbeta appears to facilitate follicle maturation from the early antral to the preovulatory stage.

Animals↗

An immunohistochemical study of progesterone receptor in thyroidal Hürthle cells tumors.

Estrogen (ER) and progesterone (PgR) receptors are commonly represented on normal and neoplastic thyroid tissues, while a few data are available about their expression in Hürthle cells tumors. Seventeen patients who underwent thyroidectomy for a neoplasia that showed oxyphilic elements were studied by an immunohistochemical method and the presence of PgR in the 30% of them, was demonstrated, while no ER expression could be found. We tried, therefore, to establish a correlation between these proteins and age, sex or indexes of the supposed estro-progestinic concentration of our patients. None of these factors resulted significantly related to the receptors expression. Since PgR are expressed in the oxyphilic cells neoplasms, further studies on both ER, and PgR are needed in order to point out their possible biological importance.

Adenocarcinoma, Follicular↗

[Cytosolic pS2 levels and cellular proliferation in ER-positive and PgR-positive infiltrating ductal carcinomas of the breast].

OBJECTIVE: The trefoil factor 1 (TFF1/pS2) is an estrogen-induced molecule in breast tumours. We wanted to study its expression in ER+ and PgR+ infiltrating ductal carcinomas of the breast (IDCs), and to correlate it with other clinical-biological parameters and the outcome. MATERIAL AND METHODS: Cytosolic pS2 levels were measured using an IRMA (CIS. Biointernational. France) in 170 tumors. Likewise we determined the cytosolic levels of cathepsin D and tissue-type plasminogen activator (t-PA), as well as the concentrations of the epidermal growth factor receptor (EGFR), erbB2 oncoprotein, CD44v5 and CD44v6 on cell surfaces. Also the tumour size, histological grade (HG), axillary lymph node involvement, distant metastasis, ploidy, DNA index and of cellular synthesis phase (SP) was taken in account. RESULTS: The pS2-positive (> 5 ng/mg prot.) tumours showed higher concentrations of cathepsin D (p: 0.0043) and t-PA (p: 0.0089) than the pS2-negative ones. Likewise, they were less frequently HG3 (p: 0.0231), SP > 7 % (p: 0.0005) and SP > 14% (p:0.0014). During the follow-up time (r: 1-147; 50,1+/-31,7; median 37 months) the pS2-positive tumors showed a less number of recurrences (5/101 vs 6/69; p: 0.059) but not of deaths by the tumor (1/101 vs 2/69). CONCLUSIONS: These results support an inverse relationship between pS2 positivity and cellular proliferation in IDCs and suggest a new role of this protein (different of the hormone dependence) in the biology of these breast carcinomas, while further studies will be required to establish the impact of this finding on their outcome.

Adult↗

LCC15-MB: a vimentin-positive human breast cancer cell line from a femoral bone metastasis.

The LCC15-MB cell line was established from a femoral bone metastasis that arose in a 29-year-old woman initially diagnosed with an infiltrating ductal mammary adenocarcinoma. The tumor had a relatively high (8%) S-phase fraction and 1/23 positive lymph nodes (LN). Both the primary tumor and LN metastasis were positive for estrogen receptor (ER) and progesterone receptor (PgR), but lacked erbB2 expression. Approximately one year later, the patient presented with a 0.8 cm comedo-type intraductal mammary adenocarcinoma in the left breast that was negative for ER and PgR, but positive for erbB2. Thirty-five months after the initial diagnosis she was treated for acute skeletal metastasis, and stabilized with a hip replacement. At this time, tumor cells were removed from surplus involved bone, inoculated into cell culture, and developed into the LCC 15-MB cell line. The bone metastasis was a poorly differentiated adenocarcinoma lacking ER, PgR, and erbB2, characteristics shared by the LCC15-MB cells, although ER can be re-expressed by treatment of the LCC15-MB cells for 5 days with 75 microM 5-aza-2'-deoxycytidine. The LCC15-MB cell line is tumorigenic when implanted subcutaneously in NCr nu/nu mice and produces long-bone metastases after intracardiac injection. Although the bone metastasis from which the LCC15-MB cell line was derived lacked vimentin (VIM) expression, the original primary tumor and lymph node metastasis were strongly VIM positive, as are LCC15-MB cells in vitro and in nude mice. The karyotype and isozyme profiles of LCC15-MB cells are consistent with its origin from a human female, with most chromosome counts in the hypertriploid range. Thirty-two marker chromosomes are present. These cells provide an in vitro/in vivo model in which to study the inter-relationships between ER, VIM, and bone metastasis in human breast cancer.

Adult↗

Differences in oestrogen and progesterone receptors, HER-2, p53 expression and proliferation in ductal breast cancers in relation to histopathological grade.

In case of breast cancer the grade of differentiation and expression of oestrogen and progesterone receptors falls within the first category of prognostic factors according to the College of American Pathologists. HER-2, p53 and Ki67 belong to the second category and their significance still awaits confirmation. The aim of the present study was to examine the relationship between the intensity of expression of oestrogen receptors (ER), progesterone receptors (PgR), HER-2, p53 and Ki67 in cells of ductal breast cancer of G1, G2 or G3 differentiation grade. In paraffin sections of 60 ductal breast cancers (20 cases in G1, 20 in G2 and 20 in G3), immunocytochemical reactions were performed to detect the expression of ER, PgR, HER-2, p53 and Ki67. Following a semi-quantitative appraisal of the preparations under examination, appropriate statistical tests were used to document significant relationships. We noted significant positive correlations between ER and PgR (the entire group studied, G1-3, and the G1 group), HER-2 and p53 (G2) and between p53 and Ki67 expression (G2). Significant negative correlations were found between ER and p53 (G1-3), PgR and p53 (G1-3, G1, G3) and between PgR and Ki67 (G1-3, G2). The studies performed demonstrated distinct relationships between the expression intensity of various proteins in tumour cells in relation to the grade of differentiation of the tumour. We also showed that a parallel determination of ER, PgR and p53 expression may carry high predictive value as to response to tamoxifen treatment.

Biomarkers, Tumor↗

Analysis of the expression of estrogen and progesteron receptors, and of PCNA and Ki67 proliferation antigens, in uterine myomata cells in relation to the phase of the menstrual cycle.

BACKGROUND: The purpose of this study was to provide an immunocytochemical evaluation of the expression of receptors for estrogens (ER) and progesterone (PgR), and of Ki67 and PCNA (proliferating cell nuclear antigen) proliferation antigens in uterine myomata cells in three groups of patients operated in various phases of the menstrual cycle, and to determine the relationship between the expression of the receptors, the proliferative activity of myoma cells, and the phase of the menstrual cycle during which the tumor was excised. MATERIAL AND METHODS: The studies were performed on samples of uterine 85 leiomyomata. Twelve of the patients were operated in the follicular phase of menstrual cycle, 50 in the luteal phase, and 27 in the post-menopausal period. The receptors and proliferating antigens were detected immunocytochemically. The intensity of the immunocytochemical reaction was evaluated using the ImmunoReactive Score (IRS). RESULTS: In all three groups of patients the expression of PgR significantly exceeded that of ER. Also, in all the patients the mean expression of PCNA significantly exceeded the expression of Ki76. CONCLUSIONS: The expression of the studied antigens did not depend upon the phase of the menstrual cycle, and was similar in the postmenopausal period.

Adult↗

Estrogen and progesterone receptor analyses in more than 4,000 human breast cancer samples. A study with special reference to age at diagnosis and stability of analyses. Southern Swedish Breast Cancer Study Group.

Estrogen (ER) and progesterone receptors (PgR) were measured in the same laboratory in more than 4,000 breast cancer biopsy samples obtained from 15 different hospitals during ten years. ER was measured with isoelectric focusing and PgR with the dextran-coated charcoal method and Scatchard analysis. The distribution pattern for both ER and PgR was during this time period and for the different hospitals rather similar indicating a good stability of the analytical methods. ER concentration was positively correlated with patient age, with a higher percentage of positive samples and higher concentrations in patients greater than or equal to 50 years of age compared with patients less than 50 years. PgR concentration increased with age for patients under 50 years, but a considerable reduction of PgR concentration and of the proportion of positive samples was seen in patients between 50 and 59 years of age. Above this age the PgR concentration again increased with increasing age. The PgR/ER ratio and the proportion of ER- PgR+ samples were higher in patients under 50 years compared to older patients. ER and PgR values decreased during tamoxifen treatment, during pregnancy and after preoperative radiotherapy. Wet weight, DNA and protein were compared as reference parameters for the expression of ER and PgR concentrations. Strong correlations were obtained suggesting that similar information can be obtained with either of these reference parameters.

Adult↗

Simultaneous quantitative detection of relevant biomarkers in breast cancer by quantitative real-time PCR.

The assessment of ERa, PgR and HER2 status is routinely performed today to determine the endocrine responsiveness of breast cancer samples. Such determination is usually accomplished by means of immunohistochemistry and in case of HER2 amplification by means of fluorescent in situ hybridization (FISH). The analysis of these markers can be improved by simultaneous measurements using quantitative real-time PCR (Qrt-PCR). In this study we compared Qrt-PCR results for the assessment of mRNA levels of ERa, PgR, and the members of the human epidermal growth factor receptor family, HER1, HER2, HER3 and HER4. The results were obtained in two independent laboratories using two different methods, SYBR Green I and TaqMan probes, and different primers. By linear regression we demonstrated a good concordance for all six markers. The quantitative mRNA expression levels of ERa, PgR and HER2 also strongly correlated with the respective quantitative protein expression levels prospectively detected by EIA in both laboratories. In addition, HER2 mRNA expression levels correlated well with gene amplification detected by FISH in the same biopsies. Our results indicate that both Qrt-PCR methods were robust and sensitive tools for routine diagnostics and consistent with standard methodologies. The developed simultaneous assessment of several biomarkers is fast and labor effective and allows optimization of the clinical decision-making process in breast cancer tissue and/or core biopsies.

Biomarkers, Tumor↗