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Simple Summary: Breast cancer is a complex pathology characterized by several features including molecular subtype (MS). Immunohistochemistry assays were used to investigate the expression of enzymes involved in glycolysis and gluconeogenesis. The analysis involved stratifying the data based on MS, body mass index (BMI), and the combination of BMI with MS (mBMI). This study revealed significant differences in the expression of three specific enzymes—pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PCK), and fructose-1,6-bisphosphatase (FBP)—among tumor cells when stratified by MS and mBMI. Moreover, the expression levels of these enzymes were found to be closely related to hormonal receptor and HER2 status, as well as correlated pathological stage and histological grade. Obesity appeared to have an impact on these differences, particularly in the expression of PC. However, it was observed that these differences were not influenced by the presence of adipocyte deposition or inflammatory infiltration within the tumor microenvironment. Nevertheless, the expression of PCK and FBP was also influenced by the presence of obesity-related conditions such as diabetes, hypertension, and dyslipidemia. In summary, this study highlights the existence of distinct metabolic profiles for breast cancer based on its molecular subtypes, and how these profiles are affected by obesity and related health conditions. Breast cancer is a heterogeneous entity, where different molecular subtypes (MS) exhibit distinct prognostic and therapeutic responses. A series of 62 breast cancer samples stratified by MS was obtained from the tumor biobank of IPO-Porto. The expression of glycolysis and gluconeogenesis-regulating enzymes was investigated by immunohistochemistry. Data analysis included stratification according to MS, body mass index (BMI), and BMI with MS (mBMI). We observed significant differences in pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PCK), and fructose-1,6-bisphosphatase (FBP) tumor cell expression when stratified by MS and mBMI. The expression of these enzymes was also statistically dependent on hormonal receptors and HER2 status and correlated with pathological stage and histological grade. Obesity tended to attenuate these differences, particularly in PC expression, although these were not affected by adipocyte deposition or inflammatory infiltration at the tumor microenvironment. Nonetheless, PCK and FBP expression was also modified by the presence of obesity-associated disorders like diabetes, hypertension, and dyslipidemia. Taken together, these findings identify metabolic fingerprints for breast cancer as distinct histological types, which are affected by the presence of obesity and obesity-associated conditions. Despite the biological role of the differential expression of enzymes remaining unknown, the current study highlights the need to identify the expression of gluconeogenic-regulating enzymes as a tool for personalized medicine. [ABSTRACT FROM AUTHOR]

Foundation Medicine® testing is a next-generation sequence (NGS)-based platform that allows clinicians to obtain the comprehensive genomic profiling (CGP) of several cancers. By using NGS approaches, relevant genomic alterations can be identified in a short timeframe, providing guidance to diagnostic and therapeutic decisions. This study reports the implementation of three commercially available Foundation Medicine® tests in a Portuguese institution and explores the genomic alterations identified. Data obtained from 72 patients tested with Foundation Medicine® between July 2017 and December 2020 were analysed retrospectively. A total of 290 gene alterations were identified, and TP53 was the gene most frequently altered. Among the 67 successfully profiled samples, 37.3% presented a potentially actionable variation. Breast carcinoma represented the most frequent tumour-carrying variation that can be targeted using currently approved drugs. A limited number of potentially actionable variants using approved drugs was found in this study; however, the genomic information provided by Foundation Medicine® may help clinicians in directing cancer patients into clinical trials or to off-label treatments. [ABSTRACT FROM AUTHOR]

Background: The increased focus on quality indicators (QIs) and the use of clinical registries in real-world cancer studies have increased compliance with therapeutic standards and patient survival. The European Society of Breast Cancer Specialists (EUSOMA) established QIs to assess compliance with current standards in breast cancer care. Methods: This retrospective study is part of H360 Health Analysis and aims to describe compliance with EUSOMA QIs in breast cancer management in different hospital settings (public vs. private; general hospitals vs. oncology centers). A set of key performance indicators (KPIs) was selected based on EUSOMA and previously identified QIs. Secondary data were retrieved from patients' clinical records. Compliance with target KPIs in different disease stages was compared with minimum and target EUSOMA standards. Results: A total of 259 patient records were assessed. In stages I, II, and III, 18 KPIs met target EUSOMA standards, 5 met minimum standards, and 8 failed to meet minimum standards. Compliance with KPIs varied according to the type of hospital (particularly regarding diagnosis) and disease stage. Although small differences were found in KPI compliance among institutions, several statistical differences were found among treatment KPIs according to disease stage, particularly in stage III. Conclusions: This study represents the first assessment of the quality of breast cancer care in different hospital settings in Portugal and shows that, although most QIs meet EUSOMA standards, there is room for improvement. Differences have been found across institutions, particularly between oncology centers and general hospitals, in diagnosis and compliance with KPIs among disease stages. Stage III showed the greatest variability in compliance with treatment KPIs, probably related to the lower specificity of the guidelines in this disease stage. [ABSTRACT FROM AUTHOR]

Metastatic breast cancer (MBC) remains in most cases an incurable disease with genetic complexity and heterogeneity. Improvements in classification and management have been introduced, in addition to the development of endocrine and anti-HER2 targeted therapies. Currently, efforts are being made to delineate the best approach for the genomic landscape of MBC and, as result, molecular therapeutic targets. Here, we highlight the recent developments in the cytopathology of MBC, discussing cytological diagnostic approaches in the characterization of hallmarks, such as immunocytochemistry and genomic biomarkers. Cytological material can be processed for ancillary testing for diagnostic and therapeutic purposes. Reassessment of receptor status is indicated due to changes in tumor biology and metastatic presentation. PD-L1 expression is the only approved biomarker for predicting immune checkpoint inhibitor response in metastatic TNBC, evaluated by immunostaining. The feasibility of applying PD-L1 assays in MBC cytological samples can be recommended, with the adoption of a combined positive score. Non-formalin cytological samples provide higher purity, cellular yield, and better tumor fraction for single-multi gene assays. In MBC, molecular tests enable personalized therapy such as PIK3CA, NTRK fusion genes, and MSI. Cytopathology combined with molecular analysis must be performed effectively in routine clinical practice, through procedure standardization and experience dissemination. [ABSTRACT FROM AUTHOR]

The mitochondrial enzyme fumarylacetoacetate hydrolase domain‐containing protein 1 (FAHD1) was identified to be upregulated in breast cancer tissues. Here, we show that FAHD1 is indispensable for the survival of BT‐20 cells, representing the basal breast cancer cell type. A lentiviral knock‐down of FAHD1 in the breast cancer cell lines MCF‐7 and BT‐20 results in lower succinate dehydrogenase (complex II) activity. In luminal MCF‐7 cells, this leads to reduced proliferation when cultured in medium containing only glutamine as the carbon source. Of note, both cell lines show attenuated protein levels of the enzyme glutaminase (GLS) which activates programmed cell death in BT‐20. These findings demonstrate that FAHD1 is crucial for the functionality of complex II in breast cancer cells and acts on glutaminolysis in the mitochondria. [ABSTRACT FROM AUTHOR]

Background: Studies pointed out that the tumor-infiltrating lymphocytes (TILs) have considerable importance in canine mammary tumor (CMT). On the other hand, cancer cells sometimes find ways to use immune checkpoint proteins as a shield to avoid being identified and attacked by the immune system as programmed death 1 ligand 1 (PD-L1). In this study, it was investigated the relationship between PD-L1 expression, stromal tumor-infiltrating lymphocytes (TILs) in canine mammary tumor (CMT), and the association with clinical and pathological characteristics of the tumors. Materials, Methods & Results: PD-L1 expression and TILs were assessed in 23 female dogs with CMT. The tumors were grouped into simple carcinoma (CA, n = 8) and complex carcinoma (CC, n = 15). Stromal TILs were assessed using two thresholds as TILs-Low representing < 50% of infiltrate within stromal area and TILs-High representing = 50% of stromal area. Clinicopathological data of CMT was characterized according to key parameters, as well as survival rates. TILs evaluation within tumor stroma revealed that 65.2% (n = 15) of tumors had TILs-Low. PD-L1 expression and stromal TILs were significantly associated (P = 0.009). PD-L1 expression was observed in 39% (n = 9) of all tumors of which 17.4% (n = 4) were from CA group and 21.7% (n = 5) were from CC group. PD-L1 expression within TILs was observed in 39% (n = 9) of the tumors. PD-L1 in malignant epithelium was present in all lymph node metastasis (n = 5). PD-L1 was associated with involvement of regional lymph nodes (P = 0.034). Survival curves demonstrated TILs-Low had higher (P = 0.010) overall survival (OS) compared with TILs-High, and PD-L1+ and PD-L1- (P = 0.06) did not differed. The clinicopathological variables significantly correlated with OS by univariate analysis were the histological grade (P = 0.009), lymph node involvement (P = 0.004), stromal TILs (P = 0.016), and PD-L1+/TILs-High vs. PD-L1-/TILs-Low (P = 0.010). Multivariate analysis revealed that group of tumors with grade II-III was independent and negative prognostic factors for OS. Discussion: In this study, PD-L1 was differently expressed according to the histologic subtypes of TMC. Currently, has been showed the presence of PD-L1 in several canine cancer. Nevertheless, only a few studies have described PD-L1 protein expression in dog tumors and showed PD-L1 was constitutively expressed on canine tumor cell lines, although the levels of basal expression were very variable. This expression can be modulated by IFN-? exposure. In the present study, it was found a strong PD-L1 expression on TILs. The increase in PD-L1 cell surface expression by tumor cells can lead to decreased T-cell proliferation and increased apoptosis. In human breast cancer (BC) the PD-L1 expression was expressed in TILs and tumor epithelium. It has been reported the association of stromal TILs and PD-L1 expression with aggressive types and stages of BC. In this study, it was detected PD-L1 expression in malignant epithelium in all lymph node metastasis. PD-L1 overexpression was significantly associated with a series of clinicopathological parameters. It was demonstrated that PD-L1+/TILs-High had higher risk of overall survival (OS) than another group of interaction. High PDL1 expression may be a prognostic indicator for reduced OS, while tumor PD-L1+ was associated with poorer disease-free survival. The presence of TILs has shown to be potentially predictive and a prognostic factor in BC subtypes. In CMT, it has been reported that a high proportion of TILs was correlated to several malignancy characteristics. In relation to PDL1, further research is necessary to clarify this immune checkpoint as a potential therapeutic target and its application in clinical practice in CMT. [ABSTRACT FROM AUTHOR]

Despite the significant biological, behavioural and management differences between ductal carcinoma in situ (DCIS) and invasive carcinoma of the breast, they share many morphological and molecular similarities. Differentiation of these two different lesions in breast pathological diagnosis is based typically on the presence of an intact barrier between the malignant epithelial cells and stroma; namely, the myoepithelial cell (MEC) layer and surrounding basement membrane (BM). Despite being robust diagnostic criteria, the identification of MECs and BM to differentiate in‐situ from invasive carcinoma is not always straightforward. The MEC layer around DCIS may be interrupted and/or show an altered immunoprofile. MECs may be absent in some benign locally infiltrative lesions such as microglandular adenosis and infiltrating epitheliosis, and occasionally in non‐infiltrative conditions such as apocrine lesions, and in these contexts this does not denote malignancy or invasive disease with metastatic potential. MECs may also be absent around some malignant lesions such as some forms of papillary carcinoma, yet these behave in an indolent fashion akin to some DCIS. In Paget's disease, malignant mammary epithelial cells extend anteriorly from the ducts to infiltrate the epidermis of the nipple but do not typically infiltrate through the BM into the dermis. Conversely, BM‐like material can be seen around invasive carcinoma cells and around metastatic tumour cell deposits. Here, we review the role of MECs and BM in breast pathology and highlight potential clinical implications. We advise caution in interpretation of MEC features in breast pathology and mindfulness of the substantive evidence base in the literature associated with behaviour and clinical outcome of lesions classified as benign on conventional morphological examination before changing classification to an invasive lesion on the sole basis of MEC characteristics. [ABSTRACT FROM AUTHOR]

Aim To evaluate the intraobserver and interobserver reproducibility of the HER2 in-situ hybridization ( ISH) test in breast cancer by measuring the impact of counting different numbers of invasive cancer cells. Methods and results A cohort of 101 primary invasive breast cancer cases were evaluated for HER2 gene amplification by silver ISH, and the concordance among four observers with different levels of experience, counting different numbers of invasive cancer cells, was determined. The evaluation of the samples included scoring 20 nuclei, in three different areas. The cases were scored twice, with a washout interval of at least 2 weeks. We observed an increase in the intraobserver concordance rate between the first and second evaluations with an increase in cell count. A count of 60 invasive cells was needed to obtain a concordance rate near 95% and an agreement rate greater than 0.80 by all observers. The interobserver concordance rate of the HER2 test also increased with the increase in cell count, reaching at least a 90% concordance rate with a count of 60 invasive cells. The median variability of both the HER2/ CEP17 ratio and the average HER2 copy number between different evaluations decreased with the increase in cell count, being statistically higher in HER2-positive cases. Conclusions The minimal cell number recommended in current guidelines should be raised to at least 40, and preferably 60, invasive cells. Moreover, cases with amplification levels close to the threshold should be subjected to a dual count from an experienced observer. [ABSTRACT FROM AUTHOR]

Phyllodes tumours constitute an uncommon but complex group of mammary fibroepithelial lesions. Accurate and reproducible grading of these tumours has long been challenging, owing to the need to assess multiple stratified histological parameters, which may be weighted differently by individual pathologists. Distinction of benign phyllodes tumours from cellular fibroadenomas is fraught with difficulty, due to overlapping microscopic features. Similarly, separation of the malignant phyllodes tumour from spindle cell metaplastic carcinoma and primary breast sarcoma can be problematic. Phyllodes tumours are treated by surgical excision. However, there is no consensus on the definition of an appropriate surgical margin to ensure completeness of excision and reduction of recurrence risk. Interpretive subjectivity, overlapping histological diagnostic criteria, suboptimal correlation between histological classification and clinical behaviour and the lack of robust molecular predictors of outcome make further investigation of the pathogenesis of these fascinating tumours a matter of active research. This review consolidates the current understanding of their pathobiology and clinical behaviour, and includes proposals for a rational approach to the classification and management of phyllodes tumours. [ABSTRACT FROM AUTHOR]

Background: PPP2R2A deletions were recently linked to a subgroup of luminal breast carcinoma (BC) that exhibits poor survival. This subgroup also exhibited amplification of a chromosome region containing the Cyclin D1 coding gene, CCND1. Therefore, we aimed to investigate whether a combination of PPP2R2A (B55α) and Cyclin D1 expression statuses evaluated by immunohistochemistry (IHC) could define a subgroup of luminal BC that exhibits poor survival. Methods: First we conducted a retrospective cohort study using sequencing data from The Cancer Genome Atlas initiative to correlate PPP2R2A copy number alteration (CNA) status with its expression level and the corresponding overall survival (OS). Next, also using a retrospective cohort study design, we evaluated the PPP2R2A (B55α) expression levels by IHC in a total of 807 BC patients from two independent cohorts (discovery cohort n = 349 and validation cohort n = 458). Cyclin D1 expression was also evaluated, and the PPP2R2A (B55α)-/low/Cyclin D1high phenotype was evaluated as a predictor of disease-free survival (DFS) and OS in luminal-like BC patients. Results: Deletions in the PPP2R2A gene strongly correlate with lower mRNA expression and poorer OS. PPP2R2A (B55α)-/low carcinomas have significantly shorter DFS and OS. Furthermore, in univariate analysis, the PPP2R2A (B55α)-/low/Cyclin D1high phenotype is significantly associated with poorer DFS and OS. In a multivariate analysis, the PPP2R2A (B55α)-/low/Cyclin D1high phenotype is significantly associated with poor DFS, thus defining a group of luminal-like BC with higher risk of relapse. Conclusion: We demonstrate that BCs harboring PPP2R2A deletions are associated with worse OS. Moreover, this is the first study to demonstrate that the combination of altered PPP2R2A (B55α) and high Cyclin D1 expression by IHC defines a subgroup of luminal-like BC patients with a high risk of relapse and death. [ABSTRACT FROM AUTHOR]

Background: Cancer stem cells are hypoxia-resistant and present a preponderant glycolytic metabolism. These characteristics are also found in basal-like breast carcinomas (BLBC), which show increased expression of cancer stem cell markers. Recently, we demonstrated that P-cadherin, a biomarker of BLBC and a poor prognostic factor in this disease, mediates stem-like properties and resistance to radiation therapy. Thus, the aim of the present study was to evaluate if P-cadherin expression was associated to breast cancer cell populations with an adapted phenotype to hypoxia. Methods: Immunohistochemistry was performed to address the expression of P-cadherin, hypoxic, glycolytic and acid-resistance biomarkers in primary human breast carcinomas. In vitro studies were performed using basal-like breast cancer cell lines. qRT-PCR, FACS analysis, western blotting and confocal microscopy were used to assess the expression of P-cadherin after HIF-1α stabilization, achieved by CoCl2 treatment. siRNA-mediated knockdown was used to silence the expression of several targets and qRT-PCR was employed to evaluate the effects of P-cadherin on HIF-1α signaling. P-cadherin high and low breast cancer cell populations were sorted by FACS and levels of GLUT1 and CAIX were assessed by FACS and western blotting. Mammosphere forming efficiency was used to determine the stem cell activity after specific siRNA-mediated knockdown, further confirmed by western blotting. Results: We demonstrated that P-cadherin overexpression was significantly associated with the expression of HIF-1α, GLUT1, CAIX, MCT1 and CD147 in human breast carcinomas. In vitro, we showed that HIF-1α stabilization was accompanied by increased membrane expression of P-cadherin and that P-cadherin silencing led to a decrease of the mRNA levels of GLUT1 and CAIX. We also found that the cell fractions harboring high levels of P-cadherin were the same exhibiting more GLUT1 and CAIX expression. Finally, we showed that P-cadherin silencing significantly decreases the mammosphere forming efficiency in the same range as the silencing of HIF-1α, CAIX or GLUT1, validating that all these markers are being expressed by the same breast cancer stem cell population. Conclusions: Our results establish a link between aberrant P-cadherin expression and hypoxic, glycolytic and acid-resistant breast cancer cells, suggesting a possible role for this marker in cancer cell metabolism. [ABSTRACT FROM AUTHOR]

P-cadherin is a cell-cell adhesion molecule codified by the CDH3 gene, which expression is highly associated with undifferentiated cells in normal adult epithelial tissues, as well as with poorly differentiated carcinomas. In breast cancer, P-cadherin is frequently overexpressed in high-grade tumours and is a well-established indicator of aggressive tumour behaviour and poor patient prognosis. However, till now, the mechanisms controlling CDH3 gene activation have been poorly explored. Since we recently described the existence of several CCAAT/Enhancer Binding Protein β (C/EBPβ) transcription factor binding sites at the CDH3 promoter, the aim of this study was to assess if the distinct C/EBPβ isoforms were directly involved in the transcriptional activation of the CDH3 gene in breast cancer cells. DNA-protein interactions, mutation analysis and luciferase reporter assay studies have been performed. We demonstrated that C/EBPβ is co-expressed with P-cadherin in breast cancer cells and all the three isoforms function as transcriptional regulators of the CDH3 gene, directly interacting with specific regions of its promoter. Interestingly, this transcriptional activation was only reflected at the P-cadherin protein level concerning the LIP isoform. Taken together, our data show that CDH3 is a newly defined transcriptional target gene of C/EBPβ isoforms in breast cancer, and we also identified the binding sites that are relevant for this activation. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: The claudin-low molecular subtype of breast cancer includes triple negative invasive carcinomas, with a high frequency of metaplastic and medullary features. The aim of this study was to evaluate the immunohistochemistry expression of claudins in a series of metaplastic breast carcinomas. We also assessed other claudin-low features, such as the cancer stem cell-like and epithelial-to-mesenchymal transition phenotypes. Results: The majority of the cases showed weak or negative staining for membrane claudins expression. We found 76.9% (10/13) low expressing cases for claudin-1, 84.6% (11/13) for claudin-3 and claudin-4, and 92.3% (12/13) for claudin-7. Regarding the cancer stem cell marker ALDH1, 30.8% (4/13) showed positive staining. We also showed that the majority of the cases presented a CD44+CD24−/low phenotype, positivity for vimentin and lack of E-cadherin expression. Interestingly, these claudin-low molecular features were specific of the mesenchymal component of metaplastic breast carcinomas, since its frequency was very low in other breast cancer molecular subtypes, as luminal, HER2-overexpressing and non-metaplastic triple negative tumors. Conclusions: The negative/low expression of claudins and E-cadherin, high levels of vimentin, and the breast cancer stem cell phenotype suggests that metaplastic breast carcinomas have similar features to the ones included in the claudin-low molecular subtype, specially their mesenchymal components. [Copyright &y& Elsevier]

Although the luminal progenitor cell of the normal mammary gland hierarchy has been proposed as the cell-of-origin for basal-like breast cancers, finding the cancer stem cell (CSC) phenotype for this malignancy has proven a difficult task, mostly due to the lack of specific markers. Recently, basal-like sporadic and familial cases of breast cancer have been linked to BRCA1 gene inactivation, which enables the upregulation of the target-repressed CDH3/ P-cadherin gene, an important biomarker of basal-like breast carcinomas. Previously, we demonstrated that P-cadherin overexpression can mediate aggressive behavior in these tumors. Thus, our aim was to test whether P-cadherin mediates stem cell properties in basal-like breast carcinomas. Using a series of breast cancer cell lines and primary tumors, we showed that P-cadherin was directly associated with the expression of the breast stem markers CD44, CD49f, and aldehyde dehydrogenase 1 in the basal subtype. Moreover, cell population enriched for P-cadherin expression comprised increased in vitro mammosphere-forming efficiency and capacity to grow colonies in three-dimensional cultures as well as greater tumorigenicity. Importantly, an association was found with stem-/progenitor-like phenotypes of the breast, including the luminal progenitor population, CD49f+CD24+. Additionally, P-cadherin expression conferred resistance to x-ray-induced cell death, sustaining a role for this molecule in another stem cell property. In summary, we demonstrated, for the first time, that P-cadherin mediates stem cell properties, which could be explored in order to better define the CSC phenotype of basal-like breast tumors and the cell-of-origin of this malignancy. S TEM C ELLS 2012;30:854-864 [ABSTRACT FROM AUTHOR]

P-cadherin is a cell-cell adhesion molecule, whose expression is highly associated with undifferentiated cells in normal adult epithelial tissues, as well as with poorly differentiated carcinomas. Its expression has been already reported in human embryonic stem cells and it is presumed to be a marker of stem or progenitor cells of some epithelial tissues. In normal breast, P-cadherin has an essential role during ductal mammary branching, being expressed by the monolayer of epithelial cap cells at the end buds. In mature mammary tissue, its expression is restricted to the myoepithelium; it has been postulated that it may also be present in early luminal progenitor cells. In breast cancer, P-cadherin is frequently overexpressed in high-grade tumours, being a well-established indicator of poor patient prognosis. It has been reported as an important inducer of cancer cell migration and invasion, with underlying molecular mechanisms involving the signalling mediated by its juxtamembrane domain, the secretion of matrix metalloproteases to the extracellular media, and the cleavage of a P-cadherin soluble form with pro-invasive activity. Intracellularly, this protein interferes with the endogenous cadherin/catenin complex, inducing p120-catenin delocalization to the cytoplasm, and the consequent activation of Rac1/Cdc42 and associated alterations in the actin cytoskeleton. Considering P-cadherin's role in cancer cell invasion and metastasis formation, a humanized monoclonal antibody was recently produced to antagonize P-cadherin-associated signalling pathways, which is currently under Phase I clinical trials. In this review, the most important findings about the role of P-cadherin in normal breast development and cancer will be illustrated and discussed, with emphasis on the most recent data. [ABSTRACT FROM AUTHOR]

Background The sentinel lymph node (SLN) is the first lymph node to receive the lymphatic drainage of a primary tumour; based on the knowledge that CK19 is positive in more than 95% of breast carcinomas, a molecular method for intraoperative diagnosis of SLN metastases (the one-step nucleic acid amplification (OSNA) assay) was developed. Aims To evaluate CK19 immunoreactivity in a series of special histological types of breast carcinoma in order to verify whether the OSNA assay can be used in all breast cancer cases independently of the histological type. Methods 116 samples of invasive breast carcinomas of special type were investigated for CK19 immunoreactivity in tissue microarrays (TMA); negative cases were evaluated in the entire tissue tumour tissue. Results Of the 116 cases, 88.9% were positive CK19. Micropapillary and apocrine carcinomas were all positive for CK19 in TMAs. The tubular (93%), mucinous (86%), medullary typical and atypical (84%), mixed carcinomas (83%) increased the rate of positivity for this marker to 100% after repeating the immunostain in whole tissue of negative TMA cases, because the expression of those cases was focal. Conclusion Most breast cancer cases were positive for CK19, independent of the histological type; therefore the OSNA assay can be used in all breast cancer cases with a potential low rate of false negative for CK19 detection of micrometastasis. There is an important variation between the positivity assessed on TMAs and the entire tissue; these findings can be clinically relevant because in some cases CK19 is evaluated on core-needle biopsy prior to surgery. [ABSTRACT FROM AUTHOR]

Pinheiro C, Albergaria A, Paredes J, Sousa B, Dufloth R, Vieira D, Schmitt F & Baltazar F (2010) Histopathology 56, 860–867 Monocarboxylate transporter 1 is up-regulated in basal-like breast carcinoma Aims: Monocarboxylate transporters (MCTs) have been considered promising targets for cancer therapy, since they facilitate lactate efflux in glycolytic tumours. However, their role in solid tumours is still poorly understood. Thus, the present work aimed to contribute to understanding the involvement of MCT1 and MCT4 in breast cancer progression as well as MCT regulation by CD147. Methods and results: The expression of the membrane transporters MCT1 and MCT4 was analysed in a series of breast carcinomas (249 cases) and their clinicopathological significance investigated. Additionally, we analysed the significance of CD147 co-expression, as an important regulator of MCT expression and activity. MCT1 was significantly increased in breast carcinomas when compared with normal breast tissue and, importantly, both MCT1 and CD147 were associated with poor prognostic variables such as basal-like subtype and high grade tumours. Conclusions: These results provide evidence for a prognostic value of MCT1 in breast carcinoma and support the exploitation of the complex MCT1/CD147 as a promising target for cancer therapy, especially in basal-like breast carcinoma. [ABSTRACT FROM AUTHOR]

Background: Breast cancer is a heterogeneous disease associated with different patient prognosis and responses to therapy. Vitamin D has been emerging as a potential treatment for cancer, as it has been demonstrated that it modulates proliferation, apoptosis, invasion and metastasis, among others. It acts mostly through the Vitamin D receptor (VDR) and the synthesis and degradation of this hormone are regulated by the enzymes CYP27B1 and CYP24A1, respectively. We aimed to study the expression of these three proteins by immunohistochemistry in a series of breast lesions. Methods: We have used a cohort comprising normal breast, benign mammary lesions, carcinomas in situ and invasive carcinomas and assessed the expression of the VDR, CYP27B1 and CYP24A1 by immunohistochemistry. Results: The results that we have obtained show that all proteins are expressed in the various breast tissues, although at different amounts. The VDR was frequently expressed in benign lesions (93.5%) and its levels of expression were diminished in invasive tumours (56.2%). Additionally, the VDR was strongly associated with the oestrogen receptor positivity in breast carcinomas. CYP27B1 expression is slightly lower in invasive carcinomas (44.6%) than in benign lesions (55.8%). In contrast, CYP24A1 expression was augmented in carcinomas (56.0% in in situ and 53.7% in invasive carcinomas) when compared with that in benign lesions (19.0%). Conclusions: From this study, we conclude that there is a deregulation of the Vitamin D signalling and metabolic pathways in breast cancer, favouring tumour progression. Thus, during mammary malignant transformation, tumour cells lose their ability to synthesize the active form of Vitamin D and respond to VDR-mediated Vitamin D effects, while increasing their ability to degrade this hormone. [ABSTRACT FROM AUTHOR]

Monocarboxylate transporters (MCTs) are important cellular pH regulators in cancer cells; however, the value ofMCT expression in cancer is still poorly understood. In the present study, we analysed MCT1, MCT2, and MCT4 protein expression in breast, colon, lung, and ovary neoplasms, as well as CD147 and CD44. MCT expression frequency was high and heterogeneous among the different tumours. Comparing with normal tissues, there was an increase inMCT1 and MCT4 expressions in breast carcinoma and a decrease inMCT4 plasma membrane expression in lung cancer. There were associations between CD147 andMCT1 expressions in ovarian cancer as well as between CD147 and MCT4 in both breast and lung cancers. CD44 was only associated with MCT1 plasma membrane expression in lung cancer. An important number of MCT1 positive cases are negative for both chaperones, suggesting that MCT plasma membrane expression in tumours may depend on a yet nonidentified regulatory protein. [ABSTRACT FROM AUTHOR]

Aims: To evaluate the relationship between microvessel density assessed by endoglin expression and the molecular subtypes of human invasive breast carcinomas and whether there is evidence to indicate that angiogenesis could be a putative target for therapy in specific subsets of breast cancer. Methods and results: We studied a series of 161 breast carcinomas, but information was available on only 142 tumours. We correlated endoglin expression with distinct breast carcinoma subgroups classified according to immunohistochemical profiling. Additionally, we compared it with other biomarkers for the aggressive basal-like subset and with available histopathological data. Although the basal-like subtype has higher microvessel density, there are no significant differences with the other molecular subtypes of breast cancer. Conclusions: This study found no significant differences in tumour vascularity in different molecular subtypes of breast cancer. [ABSTRACT FROM AUTHOR]

Introduction: Estrogen receptor expression is lower in breast carcinoma of women ≤45 years compared to women ≥65 years of age, which may imply a higher frequency of basal-like breast carcinomas in younger women. This study evaluated whether there is any difference in the frequency of basal-like phenotype and estrogen receptor (ER)–/HER2– invasive breast carcinomas between women of these 2 different age groups. Patients and Methods: A total of 151 women aged ≤45 years or ≥65 years with invasive breast carcinomas were evaluated using tissue microarray, and classified into the following phenotypes: luminal A (ER+/HER2–), luminal B (ER+/HER2+), HER2 overexpression (ER–/HER2+), and basal-like (ER–/HER2– and expressing at least 1 of the basal markers p63, CK5 and/or P-cadherin). Results: ER–/HER2– carcinomas were twice as frequent in women aged ≤45 years (p = 0.0247). However, when the basal-like phenotype was compared with all the other phenotypes grouped together, no statistically significant difference was found (p = 0.0854). Conclusions: ER–/HER2– carcinomas were more frequent in younger women compared to all the other phenotypes grouped together. An international consensus will be necessary to establish which markers should be used to define basal-like phenotype. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: TP53 is one of major tumour suppressor genes being essential in preservation of genome integrity. Two very common polymorphisms have been demonstrated to contribute to cancer susceptibility and tumour behaviour. The purpose of this study was to evaluate the role of Arg72Pro and PIN3 Ins16bp polymorphisms in TP53 gene as genetic susceptibility and predictive markers to breast cancer. Methods: We analysed DNA samples from 264 breast cancer patients and 440 controls, for TP53 Arg72Pro and PIN3 Ins16bp polymorphisms using PCR-RFLP. Results: We observed that women with A2A2 genotype have increased risk for developing breast cancer, either in women with or without familial history (FH) of the disease (OR = 4.40, 95% CI 1.60-12.0; p = 0.004; OR = 3.88, 95% CI 1.18-12.8; p = 0.026, respectively). In haplotype analysis, statistically significant differences were found between TP53 Arg-A2 haplotype frequencies and familial breast cancer cases and the respective control group (OR = 2.10, 95% CI 1.08-4.06; p = 0.028). Furthermore, both TP53 polymorphisms are associated with higher incidence of lymph node metastases. Conclusion: Our findings suggest TP53 PIN3 Ins16bp polymorphism as a real risk modifier in breast cancer disease, either in sporadic and familial breast cancer. Furthermore, both TP53 polymorphisms are associated with higher incidence of lymph node metastases. [ABSTRACT FROM AUTHOR]

Background: P120-catenin is a member of the Armadillo protein family, which is involved in intercellular adhesion and cell signalling. It directly interacts with the classical cadherins juxtamembrane domain and contributes for both junction formation and its disassembly. Accumulating evidences indicate that p120-catenin is important in tumour formation and progression, although the role of their multiple spliced isoforms in the regulation of cadherin-mediated adhesion of malignant cells is still not well understood. We investigated the expression of p120-catenin isoforms in a collection of breast cancer cell lines with distinct molecular profiles and expressing different cadherins. Methods: We assessed the expression by RT-PCR and Western-blotting analysis. Results: We observed that the expression of p120-catenin isoforms was associated with the genomic and transcriptional phenotype of breast cancer cells. Besides, the recruitment of p120-catenin isoforms was not apparently related with the particular expression of E-, P- or N-cadherin. Conclusion: We demonstrate that mammary tumour cells exhibit a characteristic p120-catenin isoform expression profile, depending from their specific genomic and transcriptional properties. These particular expression patterns, combined with other regulatory proteins and in a specific cellular context, may explain how p120-catenin can either contribute to strength intercellular adhesions or instead to promote cell motility. [ABSTRACT FROM AUTHOR]

Background: Laboratory methods for HER2 assessment currently include immunohistochemical (IHC) methods (measuring protein overexpression) and fluorescence in situ hybridisation (FISH) (measuring gene amplification). The measure of HER2 protein by IHC is usually assessed by the mouse monoclonal antibody CB11, and polyclonal antibodies (Herceptest) directed against the internal portion of the receptor. Recently, chromogenic in situ hybridisation (CISH), in which HER2 is detected by a peroxidase reaction and the gene amplification can be determined by regular bright-field microscopy, has emerged as an alternative to FISH. Aims: To evaluate the status of HER2 in tissue microarrays (TMAs) of invasive breast cancer using the novel rabbit monoclonal antibody SP3 directed against the external portion of HER2, and correlate the results with CB11 and CISH. Methods: IHC was performed with two antibodies (CB11 and SP3) and CISH for HER2 in 10 TMA blocks with 190 formalin-fixed paraffin-embedded cases of invasive breast carcinomas. Results: The correlation between SP3 and CB11 was significant (p<0.001) with an agreement rate of 86.9%. When the staining pattern of the two antibodies was compared, the majority of SP3 immunostainings were assessed more easily, with a strong complete membrane staining pattern without non-specific cytoplasmic staining. There was a good correlation between SP3 and CISH (p<0.001). 23/24 SP3 3+ cases showed gene amplification, 97.3% of the cases without gene amplification were SP3 negative, and 6/7 SP3 2+ were amplified. Conclusion: The high level of agreement between SP3, a monoclonal antibody that recognises the extracellular domain of the HER2 receptor, and CB11 and CISH, shows that this novel antibody is a reliable candidate to evaluate the expression of HER2 in breast cancer. [ABSTRACT FROM AUTHOR]

Abstract: Immunohistochemical analysis of the expression of transforming growth factor α (TGF-α) and its receptor, epidermal growth factor receptor (EGFR), was performed in a series of 86 invasive carcinomas of the breast. TGF-α immunostaining was observed in the majority of the cases (72.1%), both in epithelial cells and in adjacent stromal cells. EGFR was also present in tumors (34.2%) and in the endothelial cells (46.1% of the cases) near the tumors. A significant association was observed between TGF-α expression and angiogenesis evaluated by immunohistochemistry using an antibody against factor VIII-related antigen. No association was observed between TGF-α expression and other clinicopathologic features. In contrast, EGFR expression in the tumor was associated with features of poor prognosis, such as tumor size, histologic grade, lymph node status, estrogen receptor content, p53 expression, sialyl-Tn expression, and age. The presence of EGFR in endothelial cells was correlated to young patient age. We also observed an association of EGFR in endothelial cells and angiogenesis in tumors with a size of less than 2 cm. Inversely, in larger tumors, angiogenesis was only associated with tumor TGF-α expression. These results indicate that endothelial EGFR may play a role in the early steps of breast cancer angiogenesis. [ABSTRACT FROM AUTHOR]

To investigate the expression of a marker of cell proliferation (MIB-1) and its putative relationship with tumor size, histologic grading, mitotic index, nodal status, estrogen receptor content, p53 immunoreactivity, and ploidy, we studied 40 cases of invasive breast carcinoma in formalin-fixed, paraffin-embedded tissue sections. The MIB-1, estrogen receptor, and p53 were detected using an avidin-biotin-peroxidase method with microwave antigen retrieval. Ploidy was assessed by image analysis. The median value of MIB-1 index was 15.9% and ranged from 5% to 90%. We found a significant and positive relationship among the MIB-1 index and histologic grading, mitotic index, p53 immunoreactivity, and ploidy, and we demonstrated an inverse relationship between the MIB-1 index and estrogen receptor content. These results are similar to those reported using Ki-67 in frozen sections from breast carcinomas. Thus, MIB-1 detected in formalin-fixed material with microwave pretreatment looks to be a reliable marker of proliferation in breast carcinomas. [ABSTRACT FROM AUTHOR]