The EndoPredict Gene-Expression Assay in Clinical Practice - Performance and Impact on Clinical Decisions.

The validated EndoPredict assay is a novel tool to predict the risk of metastases of patients with estrogen receptor positive, HER2 negative breast cancer treated with endocrine therapy alone. It has been designed to integrate genomic and clinical information and includes clinico-pathological factors such as tumor size and nodal status. The test is feasible in a decentral setting in molecular pathology laboratories. In this project, we investigated the performance of this test in clinical practice, and performed a retrospective evaluation of its impact on treatment decisions in breast cancer. During one year, EndoPredict assays from 167 patients could be successfully performed. For retrospective evaluation of treatment decisions, a questionnaire was sent to the clinical partner. Regarding the molecular EP class, samples from 56 patients (33.5%) had a low-risk, whereas 111 patients (66.5%) showed a high-risk gene profile. After integration of the clinicopathological factors the combined clinical and molecular score (EPclin) resulted in a low-risk group of 77 patients (46.4%), while 89 (53.6%) had a high risk EPclin score. The EPclin-based estimated median 10-year-risk for metastases with endocrine therapy alone was 11% for the whole cohort. The median handling time averaged three days (range: 0 to 11 days), 59.3% of the tests could be performed in three or less than three days. Comparison of pre- and post-test therapy decisions showed a change of therapy in 37.7% of patients. 16 patients (12.3%) had a change to an additional chemotherapy while 25.4% of patients (n = 33) changed to an endocrine therapy alone. In 73 patients (56.2%) no change of therapy resulted. In 6.1% of patients (n = 8), the patients did not agree to the recommendation of the tumor board. Our results show that the EndoPredict assay could be routinely performed in decentral molecular pathology laboratories and the results markedly change treatment decisions.

Differential expression of histone deacetylases HDAC1, 2 and 3 in human breast cancer--overexpression of HDAC2 and HDAC3 is associated with clinicopathological indicators of disease progression.

BACKGROUND: In breast cancer, the role of epigenetic alterations including modifications of the acetylation status of histones in carcinogenesis has been an important research focus during the last years. An increased deacetylation of histones leads to increased cell proliferation, cell migration, angiogenesis and invasion. Class 1 histone deacetylases (HDAC) seem to be most important during carcinogenesis. METHODS: The immunhistochemical expression of HDAC1, 2 and 3 was analyzed on tissue microarrays (TMAs) from 238 patients with primary breast cancer. We analyzed the nuclear staining intensity (negative, weak, moderate, strong) as well as the percentage of positive tumor cells and calculated the immunoreactivity score (0-12). Expression was correlated with clinicopathological parameters and patient survival. RESULTS: In this cohort, we found a differential positive expression of HDAC1, HDAC2 and HDAC3. HDAC2 and HDAC3 expression was significantly higher in less differentiated tumors: HDAC2 (n=207), p<0.001 and HDAC3 (n=220), p<0.001 and correlated with negative hormone receptor status: HDAC2 (n=206), p=0.02 and HDAC3 (n=219), p=0.04. Additionally, a high HDAC2 expression was significantly associated with an overexpression of HER2 (n=203, p=0.005) and the presence of nodal metastasis (n=200, p=0.04).HDAC1 was highly expressed in hormone receptor positive tumors (n=203; p<0.001). CONCLUSION: As a conclusion, our results show that the class-1 HDAC isoenzymes 1, 2 and 3 are differentially expressed in breast cancer. HDAC2 and HDAC3 are strongly expressed in subgroups of tumor with features of a more aggressive tumor type.

Higher cytoplasmic and nuclear poly(ADP-ribose) polymerase expression in familial than in sporadic breast cancer.

Poly(ADP-ribose) polymerase 1 (PARP) is a key element of the single-base excision pathway for repair of DNA single-strand breaks. To compare the cytoplasmic and nuclear poly(ADP-ribose) expression between familial (BRCA1, BRCA2, or non BRCA1/2) and sporadic breast cancer, we investigated 39 sporadic and 39 familial breast cancer cases. The two groups were matched for hormone receptor status and human epidermal growth factor receptor 2 status. Additionally, they were matched by grading with a maximum difference of ±1 degree (e.g., G2 instead of G3). Cytoplasmic PARP (cPARP) expression was significantly higher in familial compared to sporadic breast cancer (P = 0.008, chi-squared test for trends) and a high nuclear PARP expression (nPARP) was significantly more frequently observed in familial breast cancer (64 %) compared with sporadic breast cancer (36 %) (P = 0.005, chi-squared test). The overall PARP expression was significantly higher in familial breast cancer (P = 0.042, chi-squared test). In familial breast cancer, a combination of high cPARP and high nPARP expression is the most common (33 %), whereas in sporadic breast cancer, a combination of low cPARP and intermediate nPARP expression is the most common (39 %). Our results show that the overall PARP expression in familial breast cancer is higher than in sporadic breast cancer which might suggest they might respond better to treatment with PARP inhibitors.

Comparison of the RNA-based EndoPredict multigene test between core biopsies and corresponding surgical breast cancer sections.

AIM: This study compared the perfomance of the RNA-based EndoPredict multigene test on core biopsies and surgical breast cancer specimens and analysed the influence of biopsy-induced tissue injuries on the test result. METHODS: 80 formalin-fixed paraffin-embedded samples comprising paired biopsies and surgical specimens from 40 ER-positive, HER2-negative patients were evaluated. Total RNA was extracted and the EndoPredict score was determined. RESULTS: RNA yield was considerably lower in core biopsies, but sufficient to measure the assay in all samples. The EndoPredict score was highly correlated between paired samples (Pearson r=0.92), with an excellent concordance of classification into a low or high risk of metastasis (overall agreement 95%). CONCLUSIONS: The measurements are comparable between core biopsies and surgical sections, which suggest that the EndoPredict assay can be performed on core biopsy tissue. Inflammatory changes induced by presurgical biopsies had no significant effect on the RNA-based risk assessment in surgical specimens.

Decentral gene expression analysis for ER+/Her2- breast cancer: results of a proficiency testing program for the EndoPredict assay.

Gene expression profiles provide important information about the biology of breast tumors and can be used to develop prognostic tests. However, the implementation of quantitative RNA-based testing in routine molecular pathology has not been accomplished, so far. The EndoPredict assay has recently been described as a quantitative RT-PCR-based multigene expression test to identify a subgroup of hormone-receptor-positive tumors that have an excellent prognosis with endocrine therapy only. To transfer this test from bench to bedside, it is essential to evaluate the test-performance in a multicenter setting in different molecular pathology laboratories. In this study, we have evaluated the EndoPredict (EP) assay in seven different molecular pathology laboratories in Germany, Austria, and Switzerland. A set of ten formalin-fixed paraffin-embedded tumors was tested in the different labs, and the variance and accuracy of the EndoPredict assays were determined using predefined reference values. Extraction of a sufficient amount of RNA and generation of a valid EP score was possible for all 70 study samples (100%). The EP scores measured by the individual participants showed an excellent correlation with the reference values, respectively, as reflected by Pearson correlation coefficients ranging from 0.987 to 0.999. The Pearson correlation coefficient of all values compared to the reference value was 0.994. All laboratories determined EP scores for all samples differing not more than 1.0 score units from the pre-defined references. All samples were assigned to the correct EP risk group, resulting in a sensitivity and specificity of 100%, a concordance of 100%, and a kappa of 1.0. Taken together, the EndoPredict test could be successfully implemented in all seven participating laboratories and is feasible for reliable decentralized assessment of gene expression in luminal breast cancer.

Neoadjuvant chemotherapy and bevacizumab for HER2-negative breast cancer.

BACKGROUND: Bevacizumab, a monoclonal antibody against vascular endothelial growth factor A, has shown clinical efficacy in patients with human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer. We evaluated the efficacy, measured according to the rate of pathological complete response (absence of invasive and intraductal disease in the breast and the axillary lymph nodes), and the safety of adding bevacizumab to neoadjuvant chemotherapy in patients with early-stage breast cancer. METHODS: We randomly assigned 1948 patients with a median tumor size of 40 mm on palpation to receive neoadjuvant epirubicin and cyclophosphamide followed by docetaxel, with or without concomitant bevacizumab. Patients with untreated HER2-negative breast cancer were eligible if they had large tumors, hormone-receptor-negative disease, or hormone-receptor-positive disease with palpable nodes or positive findings on sentinel-node biopsy, and no increased cardiovascular or bleeding risk. RESULTS: Overall, the rates of pathological complete response were 14.9% with epirubicin and cyclophosphamide followed by docetaxel and 18.4% with epirubicin and cyclophosphamide followed by docetaxel plus bevacizumab (odds ratio with addition of bevacizumab, 1.29; 95% confidence interval, 1.02 to 1.65; P=0.04); the corresponding rates of pathological complete response were 27.9% and 39.3% among 663 patients with triple-negative tumors (P=0.003) and 7.8% and 7.7% among 1262 patients with hormone-receptor-positive tumors (P=1.00). Breast-conserving surgery was possible in 66.6% of the patients in both groups. The addition of bevacizumab, as compared with neoadjuvant therapy alone, was associated with a higher incidence of grade 3 or 4 toxic effects (febrile neutropenia, mucositis, the hand-foot syndrome, infection, and hypertension) but with a similar incidence of surgical complications. CONCLUSIONS: The addition of bevacizumab to neoadjuvant chemotherapy significantly increased the rate of pathological complete response among patients with HER2-negative early-stage breast cancer. Efficacy was restricted primarily to patients with triple-negative tumors, in whom the pathological complete response is considered to be a reliable predictor of long-term outcome. (Funded by Sanofi-Aventis and Roche, Germany; ClinicalTrials.gov number, NCT00567554.).

Androgen receptor expression in primary breast cancer and its predictive and prognostic value in patients treated with neoadjuvant chemotherapy.

The androgen receptor (AR) has been shown to be of potential prognostic importance in retrospective cohorts. We evaluated immunohistochemical AR expression on a tissue microarray of 673 core biopsies from primary breast cancer patients treated with neoadjuvant docetaxel/doxorubicin/cyclophosphamide (TAC) chemotherapy in the prospective GeparTrio phase-III trial. AR was detected in 53.2% of tumours. Lowest AR expression was detected in triple-negative breast cancers (TNBC) with 21.2%. Highest AR expression was observed in Luminal A-like tumours with 67%. In AR-positive tumours, pathological complete response (pCR) rate was 12.8% compared to 25.4% in AR-negative tumours (P < 0.0001). In multivariate analysis, AR independently predicted pCR (OR 1.86; 95% CI [1.16-2.79] P = 0.0086). Overall patients with an AR-positive tumour had a significant better disease-free (DFS) (AR-positive 78.9% vs. AR-negative 72.5%; log-rank P = 0.0329) and overall survival (OS) (88.8% vs. 82.7%; log-rank P = 0.0234) than those with AR-negative tumours. Stratified analysis revealed that in the TNBC subgroup, but not in the other subgroups defined by ER, PgR and HER2, AR expression predicted a better DFS (AR-positive 85.7% vs. AR-negative 65.5% log-rank P = 0.0544) and OS (95.2% vs. 76.2%; log-rank P = 0.0355). Within the non-pCR subgroup, AR positivity selected a group with a significant better DFS (P = 0.045) and OS (0.021) but not within the pCR group. Patients with an AR-negative tumour have a higher chance of achieving a pCR than those with an AR-positive one. But, patients with AR-positive tumours have a better survival especially if they did not achieve a pCR.

Cytoplasmic poly(adenosine diphosphate-ribose) polymerase expression is predictive and prognostic in patients with breast cancer treated with neoadjuvant chemotherapy.

PURPOSE: Poly(adenosine diphosphate-ribose) polymerase (PARP) plays a key role in DNA repair and cellular stress response. Inhibitors of PARP show promising clinical activity in metastatic, triple-negative or BRCA-mutated breast cancer. PATIENTS AND METHODS: We investigated cytoplasmic PARP (cPARP) and nuclear PARP (nPARP) expression by immunohistochemistry in 638 pretreatment biopsies from patients on the GeparTrio study and evaluated its predictive and prognostic value after neoadjuvant anthracycline/taxane-based chemotherapy. RESULTS: cPARP expression was high in 23.7%, intermediate in 50.9%, and negative in 25.4% of tumors. High cPARP expression was significantly correlated with nonlobular histology (P < .001), undifferentiated grade (P < .001), positive nodal status (P = .049), and negative hormone receptor (HR) status (P < .001) but not with human epidermal growth factor receptor 2 (HER2) status. Expression was high in 35.5% of triple-negative tumors, 24.6% of HER2-positive tumors, and 18.0% of HR-positive/HER2-negative tumors (P < .001). Pathologic complete response (pCR) rates were 26.5%, 19.1%, and 8.0% in patients with high, intermediate, or negative expression, respectively (P < .001). This predictive effect was most prominent in HR-positive tumors (P = .035) or HER2-negative tumors (P < .001). High cPARP expression was a negative, but not independent, prognostic factor for disease-free survival (DFS; P = .0025) and overall survival (OS; P = .0022). cPARP expression was highly prognostic in patients without a pCR (DFS, P < .001; OS, P < .001) and in patients with HR-positive tumors (DFS, P < .001; OS, P < .001). No such correlations were found for nPARP expression. CONCLUSION: High cPARP expression correlates with aggressive tumor pattern and predicts high sensitivity to neoadjuvant taxane/anthracycline-based chemotherapy but also unfavorable long-term prognosis. As a potential target for PARP inhibitors, cPARP-positive breast cancer might become a new, clinically relevant entity.

Genome-wide gene expression profiling of formalin-fixed paraffin-embedded breast cancer core biopsies using microarrays.

The routine workflow for invasive cancer diagnostics includes biopsy processing by formalin fixation and paraffin embedding. It has been shown only recently that this kind of sample can be used for gene expression analysis with microarrays. To support this view, the authors conducted a microarray study using formalin-fixed paraffin-embedded (FFPE) core needle biopsies from breast cancers. Typically, for the 3'-biased chip type that was used, the probe sets interrogate sequences near the poly-A-tail of the transcripts, and this kind of probe turned out to be suitable to measure RNA levels in FFPE biopsies. For ER and HER2, the authors observed strong correlations between RNA levels and protein expression (p = 0.000003 and p = 0.0022). ER and HER2 classification of the biopsies by the RNA levels was feasible with high sensitivity and specificity (AUROC = 0.93 and AUROC = 0.96). Furthermore, a signature of 346 genes was identified that correlated with ER and a signature of 528 genes that correlated with HER2 protein status. Many of these genes (ER: 63%) could be confirmed by analysis of gene expression data from frozen tissues. The findings support the notion that clinically relevant information can be gained from microarray analyses of FFPE cancer biopsies. This opens new opportunities for biomarker detection studies and the integration of microarrays into the workflow of cancer diagnostics.

Quantitative determination of estrogen receptor, progesterone receptor, and HER2 mRNA in formalin-fixed paraffin-embedded tissue--a new option for predictive biomarker assessment in breast cancer.

The development of optimized therapy strategies against malignant tumors is critically dependent on the assessment of tissue-based biomarkers in routine diagnostic tissue samples. We investigated a novel, fully automated, and xylene-free method for RNA isolation and biomarker determination using formalin-fixed paraffin-embedded (FFPE) tissue. The aim was to show that this approach is feasible and gives results that are comparable to the current gold standards. Expression of the breast cancer biomarkers ESR1, PGR, and HER2 was measured in a total of 501 FFPE tissue samples from 167 breast carcinomas, which had been stored for up to 21 years. Total RNA was extracted from tissue sections and biomarker expression was measured by kinetic RT-PCR (RT-kPCR). The results of the new method were compared with immunohistochemistry as the current gold standard.RNA was successfully isolated from all samples, with a mean yield of 1.4 µg/sample and fragment lengths of at least 150 bp in 99% of samples. RT-kPCR analysis of ESR1, PGR, and HER2 was possible in all samples. Comparing RT-kPCR results with standard IHC, we found a good concordance for ESR1 (agreement: 98.4%), PGR (84.4%), and HER2 (89.8%). We observed a low section-to-section variability of kPCR results for all 3 biomarkers (root of mean squared errors: 0.2 to 0.5 Ct values). The new approach is a reliable high-throughput instrument for standardized testing of biomarkers in clinical routine and for research studies on archived FFPE material up to 21 years old. For the assessment of ESR1, PGR, and HER2 the results are comparable to the current gold-standard.

Down-regulation of the antigen processing machinery is linked to a loss of inflammatory response in colorectal cancer.

Antitumor inflammatory response is known to inhibit tumor growth in colorectal carcinoma. The density and functionality of tumor-infiltrating lymphocytes (TIL) is regulated by the antigen processing machinery through regulator proteins such as transporters associated with antigen processing (TAP) and major histocompatibility complex (MHC) class I antigen. We aimed to investigate the in vivo association of those factors and their impact on prognosis in colorectal cancer. TAP1, TAP2 and MHC class I antigen expression, inflammatory infiltrate and TIL (CD4(+), CD8(+), and CD20(+)) were assessed by immunohistochemistry in 336 sporadic colorectal carcinomas. The factors were correlated with each other and with clinic-pathological parameters and patient outcome. We found TAP1 and TAP2 expression to be significantly associated with MHC class I antigen expression (TAP1: r = 0.363, P < .001; TAP2: r = 0.393, P < .001). Increased density of CD8(+) TIL was predominantly found in TAP1, TAP2 and MHC class I antigen-positive cases. Increased density of CD4(+) TIL was linked with TAP1 and TAP2, but not with MHC class I antigen. High CD4(+) and CD8(+) cell count but not TAP1, TAP2 and MHC class I antigen expression had favorable prognostic impact in colorectal cancer (P = .003 and P = .003, respectively). In conclusion, our data show that the expression of key components of the antigen processing machinery is tightly linked to the density of TIL, which are positive prognostic factors in colorectal cancer in vivo. This implies that modulation of these factors may help to enhance antitumor inflammatory response which in turn may improve patient prognosis.

Expression of classical NF-kappaB pathway effectors in human ovarian carcinoma.

AIMS: Functional studies have demonstrated that nuclear factor (NF)-kappaB promotes tumour progression in ovarian cancer cells. However, surprisingly little is known of the expression of effectors of the NF-kappaB pathway in human ovarian cancer in vivo. METHODS AND RESULTS: Immunohistochemistry and in situ hybridization revealed that in a cohort of 85 primary ovarian carcinomas, total p65 expression was inversely correlated to nuclear and cytoplasmic phospho-IkappaBalpha (P = 0.002 and P = 0.05, respectively), and IkappaBalpha mRNA expression (P = 0.032). In contrast, phospho-p65 expression was paralleled by the expression of nuclear (P = 0.027) and cytoplasmic phospho-IkappaBalpha (P = 0.01). Total p65 expression was an adverse prognostic factor for overall survival (P = 0.018). In contrast, total IkappaBalpha and phosphorylated nuclear and cytoplasmic IkappaBalpha expression were favourable prognostic markers (P = 0.001, P = 0.031, P = 0.001, respectively). Cytoplasmic phospho-IkappaBalpha expression remained a significant prognostic factor on multivariate analysis (P = 0.010). In cultured, stimulated OVCAR-3 ovarian cancer cells the cytoplasmic retranslocation of p65 was delayed by inhibition of the nuclear membrane transporter chromosomal region maintenance/exportin1 protein (CRM1). A positive association of p65 and CRM1 expression was demonstrated in ovarian cancer tissue (P < 0.0001). CONCLUSIONS: Total and phosphorylated IkappaBalpha protein expression might serve as markers for NF-kappaB activation in human ovarian carcinoma. Cytoplasmic localization of p65 may be related to deregulated nucleocytoplasmic transport in carcinomas overexpressing CRM1.

Tumor-associated lymphocytes as an independent predictor of response to neoadjuvant chemotherapy in breast cancer.

PURPOSE Preclinical data suggest a contribution of the immune system to chemotherapy response. In this study, we investigated the prespecified hypothesis that the presence of a lymphocytic infiltrate in cancer tissue predicts the response to neoadjuvant chemotherapy. METHODS We investigated intratumoral and stromal lymphocytes in a total of 1,058 pretherapeutic breast cancer core biopsies from two neoadjuvant anthracycline/taxane-based studies (GeparDuo, n = 218, training cohort; and GeparTrio, n = 840, validation cohort). Molecular parameters of lymphocyte recruitment and activation were evaluated by kinetic polymerase chain reaction in 134 formalin-fixed, paraffin-embedded tumor samples. Results In a multivariate regression analysis including all known predictive clinicopathologic factors, the percentage of intratumoral lymphocytes was a significant independent parameter for pathologic complete response (pCR) in both cohorts (training cohort: P = .012; validation cohort: P = .001). Lymphocyte-predominant breast cancer responded, with pCR rates of 42% (training cohort) and 40% (validation cohort). In contrast, those tumors without any infiltrating lymphocytes had pCR rates of 3% (training cohort) and 7% (validation cohort). The expression of inflammatory marker genes and proteins was linked to the histopathologic infiltrate, and logistic regression showed a significant association of the T-cell-related markers CD3D and CXCL9 with pCR. CONCLUSION The presence of tumor-associated lymphocytes in breast cancer is a new independent predictor of response to anthracycline/taxane neoadjuvant chemotherapy and provides useful information for oncologists to identify a subgroup of patients with a high benefit from this type of chemotherapy.

Vascular endothelial growth factor C mRNA expression is a prognostic factor in epithelial ovarian cancer as detected by kinetic RT-PCR in formalin-fixed paraffin-embedded tissue.

Vascular endothelial growth factor C (VEGF-C) is a well described chemotactic and growth factor for lymphatic endothelial cells. Its inhibition leads to suppression of lymphatic and distant metastases in mouse models. In ovarian cancer, the relationship between VEGF-C expression and tumor behavior has not yet been determined by a quantitative method in vivo. Therefore, we used a new technique of RNA extraction from formalin-fixed paraffin-embedded tissue samples and determined the expression levels of VEGF-C mRNA in a study group of 97 ovarian cancer patients. Expression levels were correlated with clinicopathological features and patient survival. High VEGF-C expression was associated with worse overall (p = 0.0393) and progression-free (p = 0.0155) patient survival. In the subgroups of serous tumors and high-grade tumors, VEGF-C mRNA was still a negative indicator for patient survival (p = 0.0190 and 0.0311, respectively). A trend was observed among patients with high clinical stage (p = 0.0634). In multivariate survival analysis VEGF-C mRNA retained its prognostic influence on progression-free survival (p = 0.006, HR = 0.319 with a 95% confidence interval of 0.142-0.720). High VEGF-C expression was further associated with an increased residual tumor mass after primary cytoreductive surgery. We found no correlation of VEGF-C expression with tumor grade, FIGO stage, lymph node, or distant metastases. Our study demonstrates that high VEGF-C expression is associated with aggressive tumor behavior in ovarian cancer. mRNA extracted from paraffin-embedded tumor samples is suitable for VEGF-C gene expression studies.

High class I HDAC activity and expression are associated with RelA/p65 activation in pancreatic cancer in vitro and in vivo.

BACKGROUND: The strong association between aberrant HDAC activity and the occurrence of cancer has led to the development of a variety of HDAC inhibitors (HDIs), which emerge as promising new targeted anticancer therapeutics. METHODS: Due to the pivotal role of RelA/p65 in the tumorigenesis of pancreatic neoplasia we examined the expression of class I HDACs 1, 2 and 3 in a large cohort of human pancreatic carcinomas and correlated our findings with RelA/p65 expression status. Furthermore, we investigated the impact of the HDIs SAHA and VPA on RelA/p65 activity in pancreatic cancer cell culture models. RESULTS: Class I HDACs were strongly expressed in a subset of pancreatic adenocarcinomas and high expression was significantly correlated with increased nuclear translocation of RelA/p65 (p = 0.024). The link of HDAC activity and RelA/p65 in this tumor entity was confirmed in vitro, where RelA/p65 nuclear translocation as well as RelA/p65 DNA binding activity could be markedly diminished by HDI treatment. CONCLUSION: The RelA/p65 inhibitory effects of SAHA and VPA in vitro and the close relationship of class I HDACs and RelA/p65 in vivo suggest that treatment with HDIs could serve as a promising approach to suppress NF-kappaB activity which in turn may lead to enhanced apoptosis and chemosensitization of pancreatic cancers.

Polo-like kinase isoforms in breast cancer: expression patterns and prognostic implications.

Polo-like kinase (PLK) family members are known to be functionally involved in mitotic signaling and in cytoskeletal reorganization in both normal and malignant cells. In this study, expression of PLK1 and PLK3 was determined immunohistochemically in tissue specimens of 135 breast carcinomas, and expression was correlated with clinicopathological parameters and patient prognosis. Strong PLK isoform overexpression was observed in 42.2% (PLK1) and 47.4% (PLK3) of breast carcinomas when compared with non-transformed breast tissue. A positive correlation of PLK isoform expression with tumor grade, vascular invasion, erbB2/HER-2 expression and markers of proliferative activity was evident. Additionally, an inverse correlation of PLK isoform expression and estrogen receptor status was observed. Overexpression of PLK3 but not of PLK1 was significantly linked to reduced median overall (P<0.001) and relapse-free (P=0.021) survival time. PLK3 expression remained an independent prognostic factor for overall (RR=3.2, P=0.002) and relapse-free (RR=2.9, P=0.049) survival in multivariate survival analysis. These results suggest PLK3 as a novel independent prognostic marker in breast cancer and hint toward a role for PLK isoform overexpression in disease progression. Therefore, in vivo inhibition of PLK family members might represent a rewarding approach in the development of new anticancer drugs for this tumor entity.

Expression of the ELAV-like protein HuR is associated with higher tumor grade and increased cyclooxygenase-2 expression in human breast carcinoma.

PURPOSE: The human ELAV (embryonic lethal abnormal vision)-like protein HuR stabilizes a certain group of cellular mRNAs that contain AU-rich elements in their 3'-untranslated region. Cell culture studies have shown that the mRNA of cyclooxygenase (COX)-2 can be stabilized by HuR. EXPERIMENTAL DESIGN: To investigate a possible contribution of dysregulation of mRNA stability to the progression of cancer and to overexpression of COX-2, we studied expression of HuR in 208 primary breast carcinomas by immunohistochemistry. RESULTS: There were two different staining patterns of HuR in tumor tissue of breast carcinomas: nuclear expression was seen in 61% of cases; and an additional cytoplasmic expression was seen in 30% of cases. Expression of HuR was significantly associated with increased COX-2 expression; this association was particularly significant for cytoplasmic HuR expression (P < 0.0005). We further observed a significant association of cytoplasmic (P = 0.002) or nuclear HuR (P = 0.027) expression with increased tumor grade. Only 13% of the grade 1 carcinomas showed cytoplasmic expression of HuR, compared with 46% of the grade 3 carcinomas. There was no significant correlation between HuR expression and other clinicopathological parameters such as histological type, tumor size, or nodal status as well as patient survival. CONCLUSIONS: Our results suggest that overexpression of HuR in tumor tissue may be part of a regulatory pathway that controls the mRNA stability of several important targets in tumor biology, such as COX-2. Based on our results, additional studies are necessary to investigate whether HuR might be a potential target for molecular tumor therapy.

Elevated expression of cyclooxygenase-2 is a negative prognostic factor for disease free survival and overall survival in patients with breast carcinoma.

BACKGROUND: Cyclooxygenases regulate the production of prostaglandins and play a role in tumor development and progression. The authors investigated the prognostic impact of expression of the cyclooxygenase (COX) isoforms, COX-1 and COX-2, on disease-free survival and progression-free survival in patients with primary breast carcinoma as well as the association between COX expression and other clinicopathologic parameters. METHODS: In this study COX isoform expression was determined by immunohistochemistry in a cohort of 221 patients with primary breast carcinoma. RESULTS: Expression of COX-2 was detected in 36% of breast carcinoma samples and was associated significantly with several clinicopathologic parameters, including positive lymph node status (P < 0.0005), larger tumor size (P < 0.0005), poor differentiation (P < 0.0005), vascular invasion (P = 0.03), and negative estrogen receptor status (P = 0.04). In contrast, COX-1 was expressed in 45% of tumors and was associated with smaller tumor size (P = 0.02) and with negative lymph node status (P = 0.01). In a univariate survival analysis, a significant association was observed between elevated COX-2 expression and decreases in disease-free survival (P = 0.0007) and overall survival (P = 0.02). In a multivariate analysis, expression of COX-2 was of borderline significance for disease-free survival (relative risk, 1.90; 95% confidence interval, 1.00-3.59), adjusting for tumor size, histologic grade, number of positive lymph nodes, and patient age. Elevated expression of COX-1 in tumor tissue had no statistically significant influence on patient prognosis. CONCLUSIONS: The current data suggest that increased expression of COX-2 may play a role in the progression of primary breast carcinoma. It remains to be investigated whether treatment with selective inhibitors of COX-2 may be an additional therapeutic option for patients with breast carcinoma.