Clinical and biological significance of E-cadherin protein expression in invasive lobular carcinoma of the breast

Cancer Stem Cell Plasticity Drives Therapeutic Resistance

The connection between epithelial-mesenchymal (E-M) plasticity and cancer stem cell (CSC) properties has been paradigm-shifting, linking tumor cell invasion and metastasis with therapeutic recurrence. However, despite their importance, the molecular pathways involved in generating invasive, metastatic, and therapy-resistant CSCs remain poorly understood. The enrichment of cells with a mesenchymal/CSC phenotype following therapy has been interpreted in two different ways. The original interpretation posited that therapy kills non-CSCs while sparing pre-existing CSCs. However, evidence is emerging that suggests non-CSCs can be induced into a transient, drug-tolerant, CSC-like state by chemotherapy. The ability to transition between distinct cell states may be as critical for the survival of tumor cells following therapy as it is for metastatic progression. Therefore, inhibition of the pathways that promote E-M and CSC plasticity may suppress tumor recurrence following chemotherapy. Here, we review the emerging appreciation for how plasticity confers therapeutic resistance and tumor recurrence.

Invasive Pleomorphic Lobular Carcinoma of the Breast: Pathologic, Clinical, and Therapeutic Considerations

Pleomorphic lobular carcinoma is an uncommon form of breast cancer and a subtype of invasive lobular carcinoma. It has unique histopathologic features that translate to a more aggressive phenotype with an associated poor prognosis. Unlike classical invasive lobular carcinoma, it can lose estrogen and progesterone receptor expression and demonstrate HER-2/neu amplification. It remains to be determined, however, whether the pleomorphic histology independently predicts a worse outcome or whether other known associated negative prognostic factors such as larger tumor size, increased metastatic disease, and associated worse molecular subtypes commonly present in pleomorphic carcinoma account for the poor prognosis. Here we present an updated review of the unique pathologic and clinical features of pleomorphic lobular carcinoma needed to guide management for women with this subtype of cancer.

Differential effects of tetrahydropyridinol derivatives on β-catenin signaling and invasion in human hepatocellular and breast carcinoma cells

In continuation of previous efforts to investigate the biological potency of tetrahydropyridinol derivatives, the present study synthesized three target compounds: N-(bromoacetyl)-3-carboxyethyl-2,6-diphenyl-4-O-(pentafluorobenzoyl)-Δ3-tetra-hydropyridine (5a), N-(chloroacetyl)-3-carboxyethyl-2,6-diphenyl-4-O-(pentafluorobenzoyl)-Δ3-tetrahydropyridine (5b) and N-(2-bromopropanoyl)-3-carboxyethyl-2,6-diphenyl-4-O-(pentafluorobenzoyl)-Δ3-tetrahydropyridine (5c), and examined their anticancer potency. Experiments were performed using the Sk-Hep1 and Hep3B human hepatocellular carcinoma cell lines and MDA-MB-231 breast adenocarcinoma cell line. Among the three compounds, 5a and 5b were comparably and significantly cytotoxic to the Sk-Hep1, Hep3B and MDA-MB-231 cells. The highest level of cytotoxicity was detected in theSk-Hep1 cells with half maximal inhibitory concentrations for compounds 5a and 5b at 12 and 6 µM, respectively. These two compounds induced cell cycle arrest in the Sk-Hep1 and MDA-MB-231 cells through the downregulation of β-catenin and upregulation of glycogen synthase kinase-3β and E-cadherin. By contrast, 5a and 5b induced G1 arrest in the Hep3B cells by modulating the p21 and p27 cell cycle regulatory molecules and cyclin-dependent kinase 2. In addition, 5a and 5b significantly inhibited the invasion of Sk-Hep1 and MDA-MB-231 cells. These results suggested that the 5a and 5b compounds induce cell cycle arrest by suppressing Wnt/β-catenin signaling in highly invasive Sk-Hep1 and MDA-MB-231 cells, and by inducing p53 independent cell cycle arrest in Hep3B cells.

A new rabbit monoclonal E-cadherin antibody [EP700Y] shows higher sensitivity than mouse monoclonal E-cadherin [HECD-1] antibody in breast ductal carcinomas and does not stain breast lobular carcinomas

Immunohistochemical studies have shown E-cadherin to be expressed in breast carcinomas showing a ductal histology, with a corresponding loss of expression in tumors with a lobular histology. As a result, mouse monoclonal anti-E-cadherin [HECD-1] has been used by pathologists to differentiate between ductal and lobular carcinomas, with currently published sensitivity and specificity rates of approximately 90%. Rabbit monoclonal antibodies may combine the best properties of both mouse monoclonal antibodies and rabbit antisera. Therefore, this study compares the staining sensitivity and specificity of a new rabbit monoclonal E-cadherin and the standard mouse monoclonal E-cadherin [HECD-1] in breast ductal carcinomas, and evaluates a cocktail of rabbit monoclonal E-cadherin and p120 catenin in the discrimination of ductal from lobular carcinomas. The rabbit E-cadherin showed sharper staining and increased sensitivity (80/81, 99%) than the mouse E-cadherin (75/81, 93%). The rabbit E-cadherin achieved a score of 3+ in 85.2% (69/81) of cases as compared with a 3+ in only 21.0% (17/81) of cases stained with mouse E-cadherin. All lobular carcinomas (n=37) were confirmed by the absence of E-cadherin and the diffuse cytoplasmic expression of p120 catenin. Although both the single mouse E-cadherin and dual stain can differentiate ductal from lobular lesions, the dual stain is helpful in challenging cases because of its bright pink p120 catenin and dark brown rabbit E-cadherin staining. The highly sensitive rabbit E-cadherin antibody is the preferred antibody for evaluating ductal carcinomas and for distinguishing ductal versus lobular lesions, and the dual stain was superior to the single E-cadherin stain.

Molecular Classification of Breast Carcinoma: From Traditional, Old-Fashioned Way to A New Age, and A New Way

Breast carcinoma comprises a group of diseases with specific clinical, histopathologic and molecular properties. Traditional classification use morphology to divide tumors into separate categories with differing behavior and prognosis. However, there are limitations of traditional classification systems, and new molecular methods are expected to improve classification systems. Molecular subtypes of breast carcinomas have been characterized in the last 11 years, and have been studied extensively. Much of the information accumulated in recent years, and molecular taxonomy seems to be still developing and undergoing change. The main question is whether new molecular techniques such as gene expression profiling will be accepted as gold standard in determining breast cancer subtypes, and whether molecular classification is useful in specific subtypes of breast cancer as it is in ductal carcinoma (nonspecific type). In addition, critical review of the literature reveals major problems such as poor definition, lack of reproducibility and lack of quality control in current molecular techniques and classifications. Therefore, current molecular approaches are not yet used in routine clinical practice and treatment guidance since they are immature and can even lead to incorrect assessment.

Lobular breast cancer: incidence and genetic and non-genetic risk factors

While most invasive breast cancers consist of carcinomas of the ductal type, about 10% are invasive lobular carcinomas. Invasive lobular and ductal carcinomas differ with respect to risk factors. Invasive lobular carcinoma is more strongly associated with exposure to female hormones, and therefore its incidence is more subject to variation. This is illustrated by US figures during the 1987 to 2004 period: after 12 years of increases, breast cancer incidence declined steadily from 1999 to 2004, reflecting among other causes the decreasing use of menopausal hormone therapy, and these variations were stronger for invasive lobular than for invasive ductal carcinoma. Similarly, invasive lobular carcinoma is more strongly associated with early menarche, late menopause and late age at first birth. As for genetic risk factors, four high-penetrance genes are tested in clinical practice when genetic susceptibility to breast cancer is suspected, BRCA1, BRCA2, TP53 and CDH1. Germline mutations in BRCA1 and TP53 are predominantly associated with invasive ductal carcinoma, while BRCA2 mutations are associated with both ductal and lobular cancers. CDH1, the gene coding for the E-cadherin adhesion protein, is of special interest as mutations are associated with invasive lobular carcinoma, but never with ductal carcinoma. It was initially known as the main susceptibility gene for gastric cancer of the diffuse type, but the excess of breast cancers of the lobular type in CDH1 families led researchers to identify it also as a susceptibility gene for invasive lobular carcinoma. The risk of invasive lobular carcinoma is high in female mutation carriers, as about 50% are expected to develop the disease. Carriers must therefore undergo intensive breast cancer screening, with, for example, yearly magnetic resonance imaging and mammogram starting at age 30 years.

Invasive lobular carcinoma of the breast: morphology, biomarkers and 'omics

Invasive lobular carcinoma of the breast is the most common 'special' morphological subtype of breast cancer, comprising up to 15% of all cases. Tumours are generally of a good prognostic phenotype, being low histological grade and low mitotic index, hormone receptor positive and HER2, p53 and basal marker negative, and with a generally good response to endocrine therapy. Despite this, clinicians face countless challenges in the diagnosis and long-term management of patients, as they encounter a tumour that can be difficult to detect through screening, elicits a very invasive nature, a propensity for widespread metastatic colonisation and, consequently, in some studies a worse long-term poor outcome compared with invasive carcinoma of no special type. Here we review the morphological and molecular features that underpin the disparate biological and clinical characteristics of this fascinating tumour type.

Application of immunohistochemistry in breast pathology: a review and update

CONTEXT

Immunohistochemistry is a valuable tool in routine breast pathology, used for both diagnostic and prognostic parameters. The diagnostic immunomarkers are the scope of this review. Most breast lesions can be diagnosed on routine hematoxylin-eosin sections; however, in several scenarios, such as morphologically equivocal cases or metastatic tumors of unknown primary, the appropriate application of immunohistochemistry adds true value in reaching an accurate diagnosis.

OBJECTIVE

To evaluate the diagnostic utility of the most commonly studied immunomarkers in the field of breast pathology by review of the literature, using the database of indexed articles in PubMed (US National Library of Medicine, Bethesda, Maryland) from 1976 to 2013.

DATA SOURCES

Literature review, and author's research data and personal practice experience.

CONCLUSIONS

The appropriate use of immunohistochemistry by applying a panel of immunomarkers and using a standardized technical and interpretational method will complement the morphologic assessment and aid in the accurate classification of difficult breast lesions and the identification of metastasis from a breast primary.

Invasive lobular breast cancer: the prognostic impact of histopathological grade, E-cadherin and molecular subtypes

Aims

The aim of this study was to compare breast cancer specific survival (BCSS) for invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC) and, further, to evaluate critically the prognostic value of histopathological grading of ILC and examine E-cadherin as a prognostic marker in ILC.

Methods and results

The study comprised 116 lobular and 611 ductal breast carcinomas occurring between 1961 and 2008. All cases had been classified previously according to histopathological type and grade, stained for oestrogen receptor (ER), progesterone receptor (PR), antigen Ki67 (Ki67), epithelial growth factor receptor (EGFR), cytokeratin 5 (CK5) and human epidermal growth factor receptor 2 (HER2) and classified into molecular subtypes. For the present study, immunohistochemical staining for E-cadherin was performed. The Kaplan–Meier method and Cox proportional hazards models were used in the analyses. Grade 2 tumours comprised 85.3% of the lobular tumours and 51.9% of the ductal tumours. BCSS in ILC grade 2 was comparable to that of IDC grade 3. E-cadherin-negative ILC had a poorer prognosis compared to E-cadherin positive ILC and to IDC regardless of E-cadherin status.

Conclusions

The implication of histopathological grading may differ in ILC compared to IDC. E-cadherin may be useful in prognostication in ILC and thereby influence the determination of treatment strategies for this group of women.

Invasive lobular breast cancer and its variants: how special are they for systemic therapy decisions?

The WHO classification of breast tumors distinguishes, besides invasive breast cancer 'of no special type' (former invasive ductal carcinoma, representing 60-70% of all breast cancers), 30 special types, of which invasive lobular carcinoma (ILC) is the most common (5-15%). We review the literature on (i) the specificity and heterogeneity of ILC biology as documented by various analytical techniques, including the results of molecular testing for risk of recurrence; (ii) the impact of lobular histology on prediction of prognosis and effect of systemic therapies in patients. Though it is generally admitted that ILC has a better prognosis than IDC, is endocrine responsive, and responds poorly to chemotherapy, currently available data do not unanimously support these assumptions. This review demonstrates some lack of specific data and a need for improving clinical research design to allow oncologists to make informed systemic therapy decisions in patients with ILC. Importantly, future studies should compare various endpoints in ILC breast cancer patients among the group of hormonosensitive breast cancer.

Lobular neoplasia

Lobular neoplasia (LN) is characterized by a dysfunctional E-cadherin-catenin axis, and loss of E-cadherin plays a causative role in the typical morphology of LN cells. LN is both a nonobligate precursor and a risk indicator of invasive breast cancer, and in particular, of invasive lobular carcinoma. Despite the evidence supporting the precursor role of LN, its impact on clinical management has been a matter of controversy, and conservative management remains the mainstay of treatment. In this article, an update is provided on the pathology and genetics of LN, and the management of these lesions in surgical practice is discussed.

Garbage in, garbage out: a critical evaluation of strategies used for validation of immunohistochemical biomarkers

The use of immunohistochemistry (IHC) in clinical cohorts is of paramount importance in determining the utility of a biomarker in clinical practice. A major bottleneck in translating a biomarker from bench-to-bedside is the lack of well characterized, specific antibodies suitable for IHC. Despite the widespread use of IHC as a biomarker validation tool, no universally accepted standardization guidelines have been developed to determine the applicability of particular antibodies for IHC prior to its use. In this review, we discuss the technical challenges faced by the use of immunohistochemical biomarkers and rigorously explore classical and emerging antibody validation technologies. Based on our review of these technologies, we provide strict criteria for the pragmatic validation of antibodies for use in immunohistochemical assays.

Diagnostic role of immunohistochemistry in the evaluation of breast pathology specimens

CONTEXT

Immunohistochemistry plays a vital role in the evaluation of breast pathology specimens.

OBJECTIVE

To discuss the role of myoepithelial cell markers in the evaluation of various breast lesions. Other markers, such as E-cadherin and those used to differentiate mammary carcinoma from metastatic tumors to the breast, and markers used in the differential diagnosis of Paget disease, are also discussed.

DATA SOURCES

Data were obtained from review of the pertinent peer-reviewed literature.

CONCLUSIONS

Myoepithelial cell markers vary in their sensitivity and specificity, and one should be aware of the potential pitfalls in interpretation. Using panels of 2 or more myoepithelial cell markers is always recommended, either singly or in cocktail forms. Although negative E-cadherin staining supports the diagnosis of lobular origin, positive staining does not rule it out. Immunohistochemistry can be helpful in differentiating Paget disease from its mimics. Although metastatic tumors to the breast are rare, a triple-negative immunophenotype and absence of an in situ component should be a "red flag" for such possibility, especially in patients with clinical history of an extramammary malignancy.

Invasive lobular carcinoma of the breast: long-term prognostic value of Ki67 and histological grade, alone and in combination with estrogen receptor

Background

The aim of the present study was to investigate the long-term impact of prognostic factors in invasive lobular carcinoma (ILC) of the breast, with a primary focus on Ki67 and histological grade, alone and in combination with estrogen receptor (ER).

Material and methods

One hundred and ninety two well-characterised patients with ILC were included in the study. Ki67, histological grade and ER were evaluated and combined into a prognostic index (KiGE). All grade 1 tumours and ER-positive (ER+) grade 2 tumours with Ki67 ≤ 30% were classified as low-KiGE and all the others as high-KiGE.

Results

Overall, 31% of the patients have died from breast cancer. The median follow-up of the patients still alive was 21 years. Age, tumour size, axillary lymph node status (nodal status), histological grade, Ki67 and KiGE were significant prognostic factors for breast cancer mortality (BCM) in univariable analysis. In a multivariable model, adjusted for adjuvant treatment, age and progesterone receptor (PgR), the strongest prognostic factors for BCM were: Nodal status (hazard ratio (HR) = 2.9, 95% confidence interval (95% CI): 1.4-6.1), KiGE (HR = 2.0, 95% CI: 1.1-3.6), and tumour size (HR = 1.9, 95% CI: 0.98-3.8). By combining these three factors, 37% of the ILC’s could be further divided into a low-risk group, consisting of node negative small (≤ 20 mm) low-KiGE tumours, with a BCM of 5% (95% CI: 1-13%) at 10 years and 12% (95% CI: 5-22%) at 20 years follow-up. None of these patients recieved chemotherapy and only 2 recieved endocrine treatment with tamoxifen.

Conclusions

The combination of Ki67, histological grade and ER into KiGE, together with tumour size and nodal status make it possible to identify a large group of ILC patients with such a good long-term prognosis that chemotherapy can be safely avoided and exclusion of endocrine therapy considered.

Role of CDH1 promoter polymorphism and DNA methylation in bladder carcinogenesis: a meta-analysis

Increasing scientific evidences suggest that CDH1 gene promoter polymorphism and DNA methylation may contribute to the development and progression of bladder cancer, but many existing studies have yielded inconclusive results. This meta-analysis aims to assess the role of CDH1 gene promoter polymorphism and methylation in bladder carcinogenesis. An extensive literature search for relevant studies was conducted in PubMed, Embase, Web of Science, Cochrane Library, and CBM databases from their inception through April 1, 2013. This meta-analysis was performed using the STATA 12.0 software. The crude odds ratio with 95% confidence interval was calculated. Fifteen studies were included in this meta-analysis with a total of 824 bladder cancer patients and 818 healthy controls being assessed. Our meta-analysis revealed that the A variant of CDH1 -160C/A polymorphism was associated with an increased risk of bladder cancer. Further analysis by pathological subtype indicated that patients with invasive carcinoma had a higher frequency of CDH1 -160A variant than those with superficial carcinoma. We analyzed the methylation frequency of CDH1 gene in 608 bladder cancer samples and 338 normal bladder samples. Our data strongly suggest that the CDH1 promoter methylation frequencies in bladder cancer tissues were greater than those in normal control tissues. In conclusion, our meta-analysis indicates that promoter polymorphism and methylation of CDH1 gene may be involved in the development and progression of bladder cancer. CDH1 gene promoter polymorphism and methylation might be promising biomarkers for the diagnosis and prognosis of bladder cancer.

p120 catenin: an essential regulator of cadherin stability, adhesion-induced signaling, and cancer progression

p120 catenin is the best studied member of a subfamily of proteins that associate with the cadherin juxtamembrane domain to suppress cadherin endocytosis. p120 also recruits the minus ends of microtubules to the cadherin complex, leading to junction maturation. In addition, p120 regulates the activity of Rho family GTPases through multiple interactions with Rho GEFs, GAPs, Rho GTPases, and their effectors. Nuclear signaling is affected by the interaction of p120 with Kaiso, a transcription factor regulating Wnt-responsive genes as well as transcriptionally repressing methylated promoters. Multiple alternatively spliced p120 isoforms and complex phosphorylation events affect these p120 functions. In cancer, reduced p120 expression correlates with reduced E-cadherin function and with tumor progression. In contrast, in tumor cells that have lost E-cadherin expression, p120 promotes cell invasion and anchorage-independent growth. Furthermore, p120 is required for Src-induced oncogenic transformation and provides a potential target for future therapeutic interventions.

The Utility of Immunohistochemistry for Providing Genetic Information on Tumors

With advances in immunohistochemical technology and growing knowledge of the molecular genetics of tumors, immunohistochemistry is playing an increasingly important role in providing genetic information for tumors. Specific chromosomal translocations can be demonstrated through detection of the protein product of one of the genes involved in gene fusion (such as BCL2, cyclin D, and ALK). Some mutations can be detected by (1) aberrant localization of the protein product (such as β-catenin and nucleophosmin), (2) abnormal accumulation of the protein product as a result of stabilization of the protein (such as p53), and (3) mutation-specific antibodies directed against the mutant protein (such as isocitrate dehydrogenase gene R132H mutation, epidermal growth factor receptor gene L858R and exon 19 deletion mutations, and BRAF gene V600E mutation). Gene deletion or loss of function can be demonstrated by the loss of immunostaining for the protein product (such as mismatch repair proteins in microsatellite-unstable tumors, E-cadherin in lobular carcinoma of the breast, and INI1 in rhabdoid tumors, atypical teratoid/rhabdoid tumors, and epithelioid sarcomas). Gene amplification can be demonstrated by overexpression of the protein product (such as HER2 in breast and gastric cancers, and MDM2 or CDK4 in well-differentiated/dedifferentiated liposarcomas). Viruses associated with tumors can be demonstrated directly (such as Epstein-Barr virus latent membrane protein-1 in Hodgkin lymphomas, human herpesvirus 8 in Kaposi sarcomas, and Merkel cell polyomavirus in Merkel cell carcinomas) or by a surrogate marker (such as p16 in human papillomavirus infection). In this review, examples are given to illustrate the principles and pitfalls of these applications.

Invasive lobular carcinoma of the breast: patient response to systemic endocrine therapy and hormone response in model systems

Invasive lobular carcinoma of the breast (ILC) represents 10-15% of all newly diagnosed breast cancers, affecting ∼30,000 women annually in the United States. However, ILC is critically understudied as a breast cancer subtype. Though the vast majority of ILC are estrogen receptor-positive and present with overall favorable biomarkers, ILC patients do not benefit from improved outcomes versus other breast cancer patients. Patient outcomes, in particular in response to endocrine therapies, are not well understood in ILC, due in large part to the lack of prospective identification in large clinical trials. Further, there is a lack of laboratory models to study cell signaling, hormone response, and endocrine resistance in ILC. In this review, we provide an overview of clinicopathological features of ILC tumors, discuss issues with clinical management, and highlight the disconnect between ILC biomarkers and patient outcomes. We review currently available data on ILC patient outcomes, with a focus on response to endocrine therapy. Additionally, we describe currently available laboratory models for understanding hormone response in ILC cells, and review current data on these model systems. The promise for new insight into ILC, based on extensive representation of the disease in recent large scale genomic studies, is also discussed. Increasing understanding of endocrine response in ILC represents a critical area for future research to improve patient outcomes for this understudied breast cancer subtype.

Immunohistochemistry applied to the differential diagnosis between ductal and lobular carcinoma of the breast

The distinction between classic lobular and ductal carcinoma, both in situ and invasive, has important therapeutic and management implications. Most ductal and lobular carcinomas are distinguished readily on hematoxylin-eosin-stained sections because of distinct histomorphologic features. In cases with ambiguous morphologic features, however, categorization in one or another type can be a challenge. Several immunohistochemical markers, including epithelial cadherin, p120, β-catenin, and low-molecular-weight and high-molecular-weight cytokeratins among others, have been introduced to help better discriminate between lobular neoplasia and ductal carcinoma. In this critical review of the literature, we comment about the usefulness and the limitations of these markers to improve the accuracy in the differential diagnosis of breast pathology.

Clinicopathological significance of platelet-derived growth factor B, platelet-derived growth factor receptor-β, and E-cadherin expression in gastric carcinoma

Aim of the study

Platelet-derived growth factor B (PDGF-B), a vital growth factor which can induce angiogenesis and epithelial-mesenchymal transition (EMT), is important in the metastasis of many tumors. However, the roles of PDGF-B in gastric carcinoma are largely unknown. We investigated the correlation between PDGF-B, PDGFR-β and E-cadherin expression with the clinical features of gastric carcinoma patients to evaluate the relationship between PDGF-B signaling, E-cadherin and metastasis of gastric carcinoma, the correlation between PDGF-B and E-cadherin expression to assess the roles of PDGF-B signaling in metastasis of gastric carcinoma..

Material and methods

We detected expressions of PDGF-B, PDGFR-β and E-cadherin in gastric carcinoma tissues and normal gastric mucosa tissues of 64 patients with gastric carcinoma who had undergone surgical resection, and investigated their relationships with clinical features and the relationships between PDGF-B and E-cadherin expression in gastric carcinoma.

Results

In surgical specimens, tumor cells expressed PDGF-B, and PDGFR-β was expressed by tumor stromal cells. E-cadherin was expressed by both tumor cells and normal gastric mucosa cells. Expressions of PDGF-B and PDGFR-β were increased in gastric carcinoma tissues (p < 0.05) and were positively correlated with the depth of cancer invasion, lymph node metastasis and TNM stage (p < 0.05). The expression of E-cadherin was reduced in gastric carcinoma tissues (p < 0.05) and was negatively correlated with the depth of cancer invasion, lymph node metastasis and TNM stage (p < 0.05). The correlation between PDGF-B and E-cadherin expression was negative (p < 0.05).

Conclusion

Our data indicate that either the overexpression of PDGF-B and PDGFR-β or the underexpression of E-cadherin is correlated with cancer progression and lymphogenous metastasis of gastric carcinoma. The PDGF-B signal pathway might induce EMT by down-regulating expression of E-cadherin to promote metastasis of gastric carcinoma.

Pleomorphic lobular carcinoma of the breast: is it a prognostically significant pathological subtype independent of histological grade?

Pleomorphic lobular carcinoma is regarded as a biologically aggressive variant of invasive lobular carcinoma of the breast. However, there is no consensus on the definition and whether this subtype adds useful information to histological grade. Two-hundred and two grade 2 or grade 3 invasive lobular carcinomas were studied. Tumours were categorised according to the components of histological grade: tubules, pleomorphism and mitoses. Pleomorphic lobular carcinoma was defined as a carcinoma with a lobular growth pattern and marked nuclear pleomorphism (pleomorphism 3). Breast cancer-specific survival was used in analysis of prognosis. Grade 3 pleomorphic lobular carcinomas (tubules 3, pleomorphism 3, mitoses 2 and tubules 3, pleomorphism 3, mitoses 3) had a worse prognosis than grade 2 (tubules 3, pleomorphism 2, mitoses 1) carcinomas. Grade 2 lobular carcinomas with marked nuclear pleomorphism (tubules 3, pleomorphism 3, mitoses 1) had a similar prognosis to grade 2 carcinomas with moderate pleomorphism (tubules 3, pleomorphism 2, mitoses 1). Survival was associated with mitotic score, but not with nuclear pleomorphism on both univariate and multivariate analysis. A non-classical growth pattern was seen more frequently in all subgroups with marked nuclear pleomorphism and was associated with worse survival. Histological grade and nodal status were independent of prognostic factors. This study shows that histological grade (in particular the mitotic component) in invasive lobular carcinomas is of prognostic importance, but pleomorphic type does not provide useful additional prognostic information.

E-cadherin expression: a diagnostic utility for differentiating breast carcinomas with ductal and lobular morphologies

OBJECTIVES

The objective of this study was to evaluate the diagnostic utility of the E-Cadherin (EC) expression in differentiating between an infiltrating ductal carcinoma (IDC) and an infiltrating lobular carcinoma (ILC), the two most common forms of invasive breast carcinomas.

METHODS

The authors evaluated the E-Cadherin expression by doing immunohistochemistical studies of all the cases of invasive lobular carcinomas (ILC) which were diagnosed in the pathology laboratory during a 3 year period and they compared the expression of E-Cadherin in an equal number of invasive ductal carcinomas (IDC) of the breast.

RESULTS

A moderate to strong inter-membranous E-Cadherin expression on immunohistochemistry was seen in all the cases of IDC, while only 1 case of ILC showed a moderate E-Cadherin expression. Hence, the E-cadherin expression can be reliably used as a marker to differentiate IDC and ILC. However, an aberrant cytoplasmic expression of E-Cadherin may be seen in some cases of ILC, which should be interpreted with caution.

Use of immunohistochemistry in the diagnosis of problematic breast lesions

Most diagnoses in breast pathology can be made with H&E sections. Nevertheless immunohistochemistry plays a useful supplementary role. This article reviews the common uses of immunohistochemistry in diagnostic breast pathology. It is important to be aware of the limitations of individual antibodies. Such problems can often be overcome by using panels of antibodies. Quality control is also essential: internal and external controls should show appropriate staining. Immunohistochemistry must be interpreted in combination with the morphology seen on H&E sections. Myoepithelial markers, such as smooth muscle actin, smooth muscle myosin heavy chain and p63, are useful for distinguishing invasive carcinoma from sclerosing lesions and ductal carcinoma in situ (DCIS), and in the classification of papillary lesions. Basal cytokeratins can help distinguish epithelial hyperplasia of usual type (UEH) and clonal proliferations such as DCIS and lobular carcinoma in situ (LCIS). UEH usually shows patchy expression whereas DCIS and other clonal proliferations are typically negative. E-cadherin can usually separate DCIS and LCIS: DCIS typically shows membrane staining and most LCIS is negative. Cytokeratins can be used to detect small nodal metastases or subtle invasive carcinomas such as invasive lobular carcinomas. Immunohistochemistry plays a useful role in diagnosing spindle cell lesions such as a panel of cytokeratins to identify spindle cell carcinomas. Immunohistochemistry is helpful in recognising metastases to the breast. Different antibodies are useful for different tumours: WT1 for ovarian carcinoma; TTF1 for pulmonary adenocarcinoma; S100, melan-A and HMB45 for melanoma; and lymphoid markers for lymphoma.

Further evidence that E-cadherin is not a tumour suppressor gene in invasive ductal carcinoma of the breast: an immunohistochemical study

AIMS

E-cadherin is a cell adhesion molecule expressed in normal breast tissue; it is used generally as a phenotypical marker in breast cancer, with the absence of its expression observed frequently in lobular tumours. We have reported E-cadherin expression previously in 1516 ductal breast carcinoma using tissue microarray (TMA), where 7% of cases showed a complete absence of membrane staining. In this study, we investigated further the existence of E-cadherin-negative ductal carcinoma and evaluated the status of the E-cadherin-catenin complex in this subgroup.

MATERIAL AND METHODS

Full-face sections from excision specimens of 72 ductal breast carcinomas reported previously as E-cadherin-negative were assessed morphologically using haematoxylin and eosin staining, and immunohistochemically using two E-cadherin antibodies (HECD-1 and CDH1/4A2C7) and antibodies recognizing β-catenin and p120 proteins. Only membrane expression was considered.

RESULTS

Forty-seven ductal carcinomas were assessed after the exclusion of inappropriate cases; 34 of these showed positive E-cadherin (HECD-1) membrane expression which was focal and weak and seen mainly in invasion fronts. Ten cases showed E-cadherin (4A2C7) staining. Staining for p120 and β-catenin showed membrane staining in all cases for both antibodies, which was variable in both intensity and the proportion of positive cells.

CONCLUSION

These results demonstrate that E-cadherin-negative ductal carcinoma is rare, and in these cases p120 and β-catenin maintained their membranous localization, suggesting a functional E-cadherin-membrane complex.

The microRNA maturation regulator Drosha is an independent predictor of outcome in breast cancer patients

Drosha is a protein that plays a key role in the biogenesis of microRNAs which are well known to be deranged in human breast cancer (BC). The purpose of the current study was to assess the biological and prognostic value of Drosha protein expression in BC. Drosha protein expression was assessed immunohistochemically in two sets of BC: (1) full-face sections of selected BC series with distinct stages of tumour progression (Normal parenchymal cells, ductal carcinoma in situ (DCIS), primary invasive BC and nodal metastases) to evaluate its differential expression, (2) tissue microarray comprising a large and well-characterised series of unselected clinically annotated invasive BC to investigate its correlation with clinicopathological features and patient outcome. A gradual loss of Drosha cytoplasmic expression was observed along tumour progression from DCIS, to invasive and to metastatic cancer cells. In invasive BC, loss of Drosha cytoplasmic expression was associated with BRCA1 and ER expression and with shorter BC specific survival (BCSS), disease free interval (DFI) and distant metastasis free interval (DMFI). This correlation was maintained in ER negative, HER2 negative, triple negative and LN negative cases. Moreover, loss of cytoplasmic Drosha was predictive of better response to chemotherapy and endocrine therapy. This study provides evidence that Drosha protein potentially plays an important role in BC progression and assessment of its expression provides an independent predictor of patient outcome. These observations provide further evidence that alterations in miRNA regulation influence tumour behaviour.

Invasive Lobular Carcinoma of the Breast

Invasive lobular carcinoma of the breast is a distinct histologic type with specific clinical, radiologic, and microscopic features, which is increasing in incidence in the Western World. Routine pathologic prognostic factors, including grade, lymph node stage, and size are of significance in predicting outcome in this group of patients who, overall, have survival comparable to those with other subtypes of breast cancer. Variants, however, are seen and these, as well as other standard factors such as histologic grade, have prognostic significance and should be recorded in pathology reports.

Loss of Dicer expression is associated with breast cancer progression and recurrence

Dicer is a protein that plays a pivotal role in the final steps of the microRNA (miRNA) processing pathway, to produce mature miRNAs from their precursor molecules. The purpose of the current study was to assess the biological and prognostic value of Dicer protein expression in breast cancer (BC). Dicer protein expression was assessed immunohistochemically in two sets of BC: (1) full-face sections of selected BC series with distinct stages of tumour progression (normal, in situ (DCIS), primary invasive BC and nodal metastases) to evaluate its differential expression. (2) Tissue microarray comprising a large and well-characterised series of unselected clinically annotated invasive BC (n = 1,174) to investigate its correlation with clinicopathological features and patient outcome. A gradual loss of Dicer protein expression was observed in malignant compared to normal breast tissues, with the loss being the least in DCIS and most prominent in metastatic malignant cells. In invasive BC, loss of Dicer expression was associated with features of aggressive behaviour including higher histological grade, loss of hormone receptor and BRCA1 protein expression and with shorter disease-free survival (DFS). Dicer expression was an independent predictor of recurrence in the aggressive HER2-positive subgroup. Moreover, loss of Dicer was predictive of better response to chemotherapy and to endocrine therapy. This study provides evidence that Dicer protein plays a role in human BC progression and behaviour, and assessment of its expression could provide prognostic information in BC including the HER2-positive class.

Glucocorticoids and histone deacetylase inhibitors cooperate to block the invasiveness of basal-like breast cancer cells through novel mechanisms

Aggressive cancers often express E-cadherin in cytoplasmic vesicles rather than on the plasma membrane and this may contribute to the invasive phenotype of these tumors. Therapeutic strategies are not currently available that restore the anti-invasive function of E-cadherin in cancers. MDA-MB-231 cells are a frequently used model of invasive triple-negative breast cancer, and these cells express low levels of E-cadherin that is mislocalized to cytoplasmic vesicles. MDA-MB-231 cell lines stably expressing wild-type E-cadherin or E-cadherin fused to glutathione S-transferase or green fluorescent protein were used as experimental systems to probe the mechanisms responsible for cytoplasmic E-cadherin localization in invasive cancers. Although E-cadherin expression partly reduced cell invasion in vitro, E-cadherin was largely localized to the cytoplasm and did not block the invasiveness of the corresponding orthotopic xenograft tumors. Further studies indicated that the glucocorticoid dexamethasone and the highly potent class I histone deacetylase (HDAC) inhibitor largazole cooperated to induce E-cadherin localization to the plasma membrane in triple-negative breast cancers, and to suppress cellular invasion in vitro. Dexamethasone blocked the production of the cleaved form of the CDCP1 (that is, CUB domain-containing protein 1) protein (cCDCP1) previously implicated in the pro-invasive activities of CDCP1 by upregulating the serine protease inhibitor plasminogen activator inhibitor-1. E-cadherin preferentially associated with cCDCP1 compared with the full-length form. In contrast, largazole did not influence CDCP1 cleavage, but increased the association of E-cadherin with γ-catenin. This effect on E-cadherin/γ-catenin complexes was shared with the nonisoform selective HDAC inhibitors trichostatin A (TSA) and vorinostat (suberoylanilide hydroxamic acid, SAHA), although largazole upregulated endogenous E-cadherin levels more strongly than TSA. These results demonstrate that glucocorticoids and HDAC inhibitors, both of which are currently in clinical use, cooperate to suppress the invasiveness of breast cancer cells through novel, complementary mechanisms that converge on E-cadherin.

Genetic up-regulation and overexpression of PLEKHA7 differentiates invasive lobular carcinomas from invasive ductal carcinomas

Molecular differentiation between invasive lobular carcinomas (ILCs) and invasive ductal carcinomas (IDCs) of the breast has not been well defined. We investigated gene expression differences between ILCs and IDCs and their correlation with variations in invasiveness and tumor growth. Total RNA was isolated from 30 frozen tumor samples: 10 from ILCs and 20 from IDCs. Gene expression was investigated using the Affymetrix GeneChip Human Gene 1.0 ST Array (Affymetrix, Santa Clara, CA). Data and validation were performed by reverse transcriptase polymerase chain reaction and immunohistochemistry. Gene expression differences between ILCs and IDCs were found in 140 genes. Overall, ILCs showed up-regulation of genes related with cell migration, lipid and fatty acid metabolism, and some transcription factors and showed down-regulation of cell adhesion, actin cytoskeleton, cell proliferation, and energetic metabolism of the tumor cells. Our reverse transcriptase polymerase chain reaction results showed that PLEKHA and TMSB10 expression discriminated ILCs from luminal A IDCs, whereas PLEKHA7, TMSB10, PRDX4, and SERPINB5 discriminated ILCs from luminal B IDCs. At the protein level, Plekha7 was overexpressed in ILCs but not in normal tissue or low-grade IDCs. Moreover, Plekha7 overexpression had an inverse relation with E-cadherin expression. The gene expression profile in ILCs and IDCs differs in several signaling pathways. Our findings suggest that overexpression of PLEKHA7 is common in ILCs and could be a molecular marker to differentiate ILCs from IDCs.

Reduced expression of E-cadherin and β-catenin and high expression of basal cytokeratins in feline mammary carcinomas with regional metastasis

Feline mammary carcinomas are highly aggressive neoplasms. Several mechanisms are thought to be involved in their progression, including the loss of epithelial adhesion molecules. The present study was carried out on 21 adenomas and 139 mammary carcinomas. Of the carcinomas, 66 were not reported to have metastasized, while the remaining 73 had evidence of regional lymph node metastasis at the moment of diagnosis. The relationship was examined between the expression of the E-cadherin-β-catenin complex and basal (CK5/6, CK14) and luminal (CK8/18) cytokeratin expression. In the medical literature, carcinomas expressing basal cytokeratins are reported as having a poor prognosis in human breast cancer. Results revealed that preservation of the expression of E-cadherin and β-catenin is a significant feature of carcinomas without metastasis, whereas carcinomas with metastasis reveal the loss of one or both adhesion molecules. Additionally, basal cytokeratin expression was statistically associated with the presence of regional metastasis. Furthermore, the expression of E-cadherin-β-catenin was significantly correlated with the high expression of CK18 and low expression of CK5/6.

Advantages of adjuvant chemotherapy for patients with triple-negative breast cancer at Stage II: usefulness of prognostic markers E-cadherin and Ki67

Introduction

Triple-negative breast cancer (TNBC), which is characterized by negativity for estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 (HER2), is a high risk breast cancer that lacks specific targets for treatment selection. Chemotherapy is, therefore, the primary systemic modality used in the treatment of this disease, but reliable parameters to predict the chemosensitivity of TNBC have not been clinically available.

Methods

A total of 190 TNBC patients who had undergone a curative resection of a primary breast cancer were enrolled. The adjuvant chemotherapy was performed for 138 (73%) of 190 TNBC cases; 60 cases had an anthracyclin-based regimen and 78 a 5-fluorouracil-based regimen. The prognostic value of E-cadherin, Ki67 and p53 expression in the outcome of TNBC patients with adjuvant chemotherapy was evaluated by immunohistochemistry.

Results

The adjuvant therapy group, especially those with Stage II TNBC, had a more favorable prognosis than the surgery only group (P = 0.0043), while there was no significant difference in prognosis between the anthracyclin-based regimen and 5-fluorouracil-based regimen. Patients with E-cadherin-negative and Ki67-positive expression showed significantly worse overall survival time than those with either E-cadherin-positive or Ki67-negative expression (P < 0.001). Multivariate analysis showed that the combination of E-cadherin-negative and Ki67-positive expression was strongly predictive of poor overall survival (P = 0.004) in TNBC patients receiving adjuvant chemotherapy. In contrast, p53 status was not a specific prognostic factor.

Conclusions

Adjuvant therapy is beneficial for Stage II TNBC patients. The combination of E-cadherin and Ki67 status might be a useful prognostic marker indicating the need for adjuvant chemotherapy in Stage II TNBC patients.

Molecular classification of breast cancer: is it time to pack up our microscopes?

Breast cancer is a heterogeneous disease. The traditional classification uses morphology to divide tumours into distinct categories with differing prognosis and behavior. Despite providing high quality data cheaply, it has limitations and hence there has been a hope that the new molecular methods may help to refine the classification systems. Much has been learned in the last few years however, the molecular taxonomy is still in evolution and likely to change over the coming years. Whether the molecular classification is as useful for special subtypes of breast cancers as it has been for ductal carcinoma, no special type, remains to be determined.