Validation of a tissue microarray to study differential protein expression in inflammatory and non-inflammatory breast cancer

Caveolin-1: an ambiguous entity in breast cancer

Breast cancer (BC) is the most frequently diagnosed cancer in women and the second leading cause of death from cancer among women. Metastasis is the major cause of BC-associated mortality. Accumulating evidence implicates Caveolin-1 (Cav-1), a structural protein of plasma membrane caveolae, in BC metastasis. Cav-1 exhibits a dual role, as both a tumor suppressor and promoter depending on the cellular context and BC subtype. This review highlights the role of Cav-1 in modulating glycolytic metabolism, tumor-stromal interactions, apoptosis, and senescence. Additionally, stromal Cav-1's expression is identified as a potential prognostic marker, offering insights into its contrasting roles in tumor suppression and progression. Furthermore, Cav-1's context-dependent effects are explored in BC subtypes including hormone receptor-positive, HER2-positive, and triple-negative BC (TNBC). The review further delves into the role of Cav-1 in regulating the metastatic cascade including extracellular matrix interactions, cell migration and invasion, and premetastatic niche formation. The later sections discuss the therapeutic targeting of Cav-1 by metabolic inhibitors such as betulinic acid and Cav-1 modulating compounds. While Cav-1 may be a potential biomarker and therapeutic target, its heterogeneous expression and context-specific activity necessitates further research to develop precise interventions. Future studies investigating the mechanistic role of Cav-1 in metastasis may pave the way for effective treatment of metastatic BC.

Inflammatory breast cancer biomarkers and biology

Inflammatory breast cancer (IBC) is a unique breast cancer with a highly virulent course and low 5- and 10-year survival rates. Even though it only accounts for 1-5% of breast cancers it is estimated to account for 10% of breast cancer deaths annually in the United States. The accuracy of diagnosis and classification of this unique cancer is a major concern within the medical community. Early molecular and biological studies incidentally included IBC samples with other conventional breast cancers and were not informative as to the unique nature of the disease. Subsequent molecular studies that focused specifically on IBC demonstrated that IBC has a unique biology different from other forms of breast cancer. Additionally, a handful of unique signature genes that are hallmarks of IBC have also been suggested. Further understanding of IBC biology can help with diagnosis and treatment of the disease. The current article reviews the history and highlights of IBC studies.

Overexpression of Annexin A1 Is an Independent Predictor of Longer Overall Survival in Epithelial Ovarian Cancer

BACKGROUND

Epithelial ovarian cancer (EOC) is the major gynecological cause of cancer deaths. Annexin A1 (ANXA1) protein has been implicated in the aggressiveness of several cancer types.

MATERIALS AND METHODS

This study retrospectively assessed ANXA1 expression in epithelial cells of 156 pre-chemotherapy EOC samples and 34 normal ovarian samples from patients treated at Salah Azaiez Institute. Using immunohistochemistry, ANXA1 expression was compared in normal versus cancer samples; correlations with clinicopathological features, including overall survival, were sought.

RESULTS

Fifty-two percent of tumor samples showed epithelial ANXA1 staining versus only 26% of normal samples (Fisher's exact test, p=0.00794). Epithelial ANXA1 expression was correlated with better overall survival in both univariate and multivariate analyses.

CONCLUSION

The possible contribution of ANXA1 overexpression to EOC outcome may be relevant to therapeutic strategies.

The Role of Tumor-Associated Myeloid Cells in Modulating Cancer Therapy

Myeloid cells include various cellular subtypes that are distinguished into mononuclear and polymorphonuclear cells, derived from either common myeloid progenitor cells (CMPs) or myeloid stem cells. They play pivotal roles in innate immunity since, following invasion by pathogens, myeloid cells are recruited and initiate phagocytosis and secretion of inflammatory cytokines into local tissues. Moreover, mounting evidence suggests that myeloid cells may also regulate cancer development by infiltrating the tumor to directly interact with cancer cells or by affecting the tumor microenvironment. Importantly, mononuclear phagocytes, including macrophages and dendritic cells (DCs), can have either a positive or negative impact on the efficacy of chemotherapy, radiotherapy as well as targeted anti-cancer therapies. Tumor-associated macrophages (TAMs), profusely found in the tumor stroma, can promote resistance to chemotherapeutic drugs, such as Taxol and Paclitaxel, whereas the suppression of TAMs can lead to an improved radiotherapy outcome. On the contrary, the presence of TAMs may be beneficial for targeted therapies as they can facilitate the accumulation of large quantities of nanoparticles carrying therapeutic compounds. Tumor infiltrating DCs, however, are generally thought to enhance cytotoxic therapies, including those using anthracyclines. This review focuses on the role of tumor-infiltrating and stroma myeloid cells in modulating tumor responses to various treatments. We herein report the impact of myeloid cells in a number of therapeutic approaches across a wide range of malignancies, as well as the efforts toward the elimination of myeloid cells or the exploitation of their presence for the enhancement of therapeutic efficacy against cancer.

Comparative aspects of canine and human inflammatory breast cancer

Inflammatory breast cancer (IBC) in humans is the most aggressive form of mammary gland cancer and shares clinical, pathologic, and molecular patterns of disease with canine inflammatory mammary carcinoma (CIMC). Despite the use of multimodal therapeutic approaches, including targeted therapies, the prognosis for IBC/CIMC remains poor. The aim of this review is to critically analyze IBC and CIMC in terms of biology and clinical features. While rodent cancer models have formed the basis of our understanding of cancer biology, the translation of this knowledge into improved outcomes has been limited. However, it is possible that a comparative "one health" approach to research, using a natural canine model of the disease, may help advance our knowledge on the biology of the disease. This will translate into better clinical outcomes for both species. We propose that CIMC has the potential to be a useful model for developing and testing novel therapies for IBC. Further, this strategy could significantly improve and accelerate the design and establishment of new clinical trials to identify novel and improved therapies for this devastating disease in a more predictable way.

Identification of frequent somatic mutations in inflammatory breast cancer

PURPOSE

Inflammatory breast cancer is an aggressive form of breast cancer that shows distinct clinical features from non-inflammatory breast cancer. Genomic understanding of inflammatory breast cancer will shed light on biological targets for this disease. Our objective was to identify targeted hotspot mutations using multiplex genome sequencing in inflammatory breast cancer and compare the findings with those for patients with non-inflammatory breast cancer to further recognize novel targets.

METHODS

We studied 400 patients with metastatic breast cancer who had somatic hotspot mutation testing using a 46- or 50-gene multiplex platform from March 2012 to December 2014. Among this population, 24 patients had inflammatory breast cancer and 376 patients had non-inflammatory breast cancer. We tested a total of 26 samples from 24 patients with inflammatory breast cancer.

RESULTS

The average number of mutations per patient was higher in inflammatory breast cancer than in non-inflammatory breast cancer (1.23 vs. 0.65, respectively). Identified somatic mutations in inflammatory breast cancer were TP53 (n = 18, 75%), PIK3CA (n = 10, 41.7%), and ERBB2 (n = 4, 16.7%). TP53 and ERBB2 mutations were significantly more prevalent in inflammatory breast cancer than in non-inflammatory breast cancer (P < 0.01). All patients with ERBB2 mutations had hormone receptor (HR)+ primary tumors.

CONCLUSIONS

TP53, PIK3CA, and ERBB2 were detected as three major somatic mutations in metastatic inflammatory breast cancer patients. While the inflammatory breast cancer TP53 and PIK3CA mutations mirrored previously reported data for metastatic non-inflammatory breast cancer, this is the first report of higher frequency of ERBB2 mutation in inflammatory breast cancer, especially in the HR+ subtype. Once validated in a larger cohort of inflammatory breast cancer patients, this novel finding could lead to development of treatments for HR+ inflammatory breast cancer.

Macrophages Enhance Migration in Inflammatory Breast Cancer Cells via RhoC GTPase Signaling

Inflammatory breast cancer (IBC) is the most lethal form of breast cancer. All IBC patients have lymph node involvement and one-third of patients already have distant metastasis at diagnosis. This propensity for metastasis is a hallmark of IBC distinguishing it from less lethal non-inflammatory breast cancers (nIBC). Genetic profiling studies have been conducted to differentiate IBC from nIBC, but no IBC cancer-cell-specific gene signature has been identified. We hypothesized that a tumor-extrinsic factor, notably tumor-associated macrophages, promotes and contributes to IBC’s extreme metastatic phenotype. To this end, we studied the effect of macrophage-conditioned media (MCM) on IBC. We show that two IBC cell lines are hyper-responsive to MCM as compared to normal-like breast and aggressive nIBC cell lines. We further interrogated IBC’s hyper-responsiveness to MCM using a microfluidic migration device, which permits individual cell migration path tracing. We found the MCM “primes” the IBC cells’ cellular machinery to become extremely migratory in response to a chemoattractant. We determined that interleukins −6, −8, and −10 within the MCM are sufficient to stimulate this enhanced IBC migration effect, and that the known metastatic oncogene, RhoC GTPase, is necessary for the enhanced migration response.

Inflammatory breast cancer: New factors contribute to disease etiology: A review

Inflammatory breast cancer (IBC) is a highly metastatic and fatal form of breast cancer. In fact, IBC is characterized by specific morphological, phenotypic, and biological properties that distinguish it from non-IBC. The aggressive behavior of IBC being more common among young women and the low survival rate alarmed researchers to explore the disease biology. Despite the basic and translational studies needed to understand IBC disease biology and identify specific biomarkers, studies are limited by few available IBC cell lines, experimental models, and paucity of patient samples. Above all, in the last decade, researchers were able to identify new factors that may play a crucial role in IBC progression. Among identified factors are cytokines, chemokines, growth factors, and proteases. In addition, viral infection was also suggested to participate in the etiology of IBC disease. In this review, we present novel factors suggested by different studies to contribute to the etiology of IBC and the proposed new therapeutic insights.

Tissue microarray-based evaluation of Chromatin Assembly Factor-1 (CAF-1)/p60 as tumour prognostic marker

In this study we aimed to confirm the emerging role of Chromatin Assembly Factor 1 (CAF-1 p60) as a new proliferation and prognostic marker for cancer and to test the usefulness of the tissue microarray technique (TMA) for CAF-1 p60 rapid screening in several human malignancies. CAF-1 is a histone chaperone, regulating chromatin dynamics during DNA replication and repair in eukaryotics. TMA is a powerful high-throughput methodology in the study of cancer, allowing simultaneous assessment of different biomarkers within large numbers of tissue specimens. We generated TMA taking 3 mm diameter-core biopsies from oral squamous cell carcinoma, prostate cancer, salivary gland tumours and skin melanoma specimens, which had been previously tested for CAF-1 p60 on routine tissue sections. We also analysed, for the first time, 30 larynx and 30 skin squamous cell carcinomas. CAF-1 p60 resulted over-expressed in both the tissue sections and the TMA specimens, with the highest levels of expression in tumours which were more aggressive and metastasizing. Notably, a high degree of agreement was found between the CAF-1 p60 assessment on TMAs and on routine tissue sections. Our findings confirm the prognostic role of CAF-1 p60 and indicate TMA as a really advantageous method for CAF-1 p60 immunohistochemical screening, allowing savings on both tissue quantity and operator-time.

Regulation of inflammatory breast cancer cell invasion through Akt1/PKBα phosphorylation of RhoC GTPase

With a 42% and 18% 5- and 10-year respective disease-free survival rate, inflammatory breast cancer (IBC) is arguably the deadliest form of breast cancer. IBC invades the dermal lymphatic vessels of the skin overlying the breast and as a consequence nearly all women have lymph node involvement and ~1/3 have gross distant metastases at the time of diagnosis. One year after diagnosis ~90% of patients have detectable metastases, making IBC a paradigm for lymphovascular invasion. Understanding the underlying mechanisms of the IBC metastatic phenotype is essential for new therapies. Work from our laboratory and others show distinct molecular differences between IBC and non-IBCs (nIBCs). Previously we showed that RhoC GTPase is a metastatic switch responsible for the invasive phenotype of IBC. In this study we integrate observations made in IBC patients with in vitro analysis. We show that the PI3K/Akt signaling pathway is crucial in IBC invasion. Key molecules involved in cytoskeletal control and cell motility are specifically upregulated in IBC patients compared with stage and cell-type-of-origin matched nIBCs patients. Distinctively, RhoC GTPase is a substrate for Akt1 and its phosphorylation is absolutely essential for IBC cell invasion. Further our data show that Akt3, not Akt1 has a role in IBC cell survival. Together our data show a unique and targetable pathway for IBC invasion and survival.

Inflammatory breast cancer: is it really a separate entity?

BACKGROUND

Inflammatory breast cancer (IBC) is the most aggressive form of primary breast carcinoma and is associated with a dismal outcome despite the availability of multi-modality treatment options.

PATIENTS AND METHODS

This is a prospective case control study comparing two groups of newly diagnosed patients; the first with inflammatory breast cancer (IBC) and the second with locally advanced non inflammatory breast cancer (LABC). In both groups MIB1, ER, PR, Her2neu were assessed. Neo-adjuvant chemotherapy consisted of four cycles of FEC100 followed by modified radical mastectomy according to clinical response, postoperative chemotherapy with two courses of the same regimen followed by radiotherapy. Tamoxifen 20 mg po daily for 5 years in ER and/or PR positive tumours, starting after the completion of radiotherapy. Primary end points were a) comparison of MIB-1 score in both groups, b) comparison of clinical and pathological responses in both groups. Secondary endpoints were comparison of progression free survival and overall survival.

RESULTS

From a total of 42 patients, 21 were stage III B (T4d, N0-2 M0) IBC and 21 were stage III B (T4a-c, N0-2, M0) LABC. Patients in the age range from 28 to 68 were included and followed from November 2007 until February 2010 with a median follow-up period of 22.5 months. Toxicity of both arms, mainly haematologic, nausea and vomiting, was in general acceptable with no treatment-related deaths. Of the patients with IBC 81.3% had a high MIB-1 score as compared with 43.8% of patients with LABC (P-value = 0.028). Objective clinical response to neo-adjuvant chemotherapy in the IBC arm was 57.1% (4.8% complete response (CR)) as compared with 81% (9.5% CR) in LABC (P-value = 0.09). Overall pathological response (complete pathological response (pCR)+partial pathological response (pPR)) was 35.3% in the IBC arm compared with 40% in LABC arm (P-value = 0.618). One year, 2 year and median progression free survival (PFS) were 55.87%, 37.71% and 21.7 months, respectively in the IBC arm compared with 85.71%, 66.67% in LABC (median PFS was not reached) (P-value = 0.072). One and 2 year overall survival (OS) were 69.82% and 51.20%, respectively in the IBC arm compared with 95.24% and 95.24% in LABC arm (P-value = 0.0038).

CONCLUSIONS

IBC should be considered as a separate entity. A high MIB-1 score is a potential molecular marker for IBC.

E-cadherin's dark side: possible role in tumor progression

In the context of cancer, E-cadherin has traditionally been categorized as a tumor suppressor, given its essential role in the formation of proper intercellular junctions, and its downregulation in the process of epithelial-mesenchymal transition (EMT) in epithelial tumor progression. Germline or somatic mutations in the E-cadherin gene (CDH1) or downregulation by epigenetic mechanisms have been described in a small subset of epithelial cancers. However, recent evidence also points toward a promoting role of E-cadherin in several aspects of tumor progression. This includes preserved (or increased) E-cadherin expression in microemboli of inflammatory breast carcinoma, a possible "mesenchymal to epithelial transition" (MET) in ovarian carcinoma, collective cell invasion in some epithelial cancers, a recent association of E-cadherin expression with a more aggressive brain tumor subset, as well as the intriguing possibility of E-cadherin involvement in specific signaling networks in the cytoplasm and/or nucleus. In this review we address a lesser-known, positive role for E-cadherin in cancer.

Alternate estrogen receptors promote invasion of inflammatory breast cancer cells via non-genomic signaling

Although Inflammatory Breast Cancer (IBC) is a rare and an aggressive type of locally advanced breast cancer with a generally worst prognosis, little work has been done in identifying the status of non-genomic signaling in the invasiveness of IBC. The present study was performed to explore the status of non-genomic signaling as affected by various estrogenic and anti-estrogenic agents in IBC cell lines SUM149 and SUM190. We have identified the presence of estrogen receptor α (ERα) variant, ERα36 in SUM149 and SUM190 cells. This variant as well as ERβ was present in a substantial concentration in IBC cells. The treatment with estradiol (E2), anti-estrogenic agents 4-hydroxytamoxifen and ICI 182780, ERβ specific ligand DPN and GPR30 agonist G1 led to a rapid activation of p-ERK1/2, suggesting the involvement of ERα36, ERβ and GPR30 in the non-genomic signaling pathway in these cells. We also found a substantial increase in the cell migration and invasiveness of SUM149 cells upon the treatment with these ligands. Both basal and ligand-induced migration and invasiveness of SUM149 cells were drastically reduced in the presence of MEK inhibitor U0126, implicating that the phosphorylation of ERK1/2 by MEK is involved in the observed motility and invasiveness of IBC cells. We also provide evidence for the upregulation of p-ERK1/2 through immunostaining in IBC patient samples. These findings suggest a role of non-genomic signaling through the activation of p-ERK1/2 in the hormonal dependence of IBC by a combination of estrogen receptors. These findings only explain the failure of traditional anti-estrogen therapies in ER-positive IBC which induces the non-genomic signaling, but also opens newer avenues for design of modified therapies targeting these estrogen receptors.

Molecular and epidemiological characteristics of inflammatory breast cancer in Algerian patients

Inflammatory breast cancer (IBC) shows a high incidence in Tunisia and Egypt but epidemiological and molecular characteristics have not been described in Algeria. We compared 117 IBC and 59 non-IBC locally advanced breast cancers (LABC), for estrogen and progesterone receptors, HER2, and EGFR protein expression by immunohistochemistry, and HER2 gene amplification by chromogenic in situ hybridization. Demographic, clinico-pathological, and molecular variables were compared with chi-square and Fisher's exact tests to test for significance (P < 0.05, two-tailed). Overall survival (OS) and disease-free survival (DFS) were plotted using Kaplan-Meier curves and compared using the log-rank test. Tumor emboli were detected in 77% of IBC. Palpable masses were found in all LABC but only in 32% of IBC (P < 0.001). Recurrences were higher in LABC than in IBC (48 vs. 35%; P = 0.14) but OS was worse in IBC (68 vs. 71%; P = 0.06). There were no significant differences between IBC and LABC by demographics or by clinico-pathological parameters. The majority of IBC and LABC tumors were luminal A (62 and 64%), followed by basal (~18%, each), triple negative (~18%, each), and HER2+ (~10%, each) subtypes. In multivariate analyses, grade was associated with worse OS (P = 0.04), and DFS (P < 0.001) in IBC; chemo- and radio-therapy were associated with improved OS and DFS, respectively (P < 0.05 for each) in LABC. In conclusion, IBC in Algeria shows similar characteristics to IBC described for Egypt and Tunisia with subtle molecular differences. Current therapeutic treatments were not very effective in this population and new approaches are much needed.

Ganoderma lucidum (Reishi) inhibits cancer cell growth and expression of key molecules in inflammatory breast cancer

Inflammatory breast cancer (IBC) is the most lethal and least understood form of advanced breast cancer. Its lethality originates from its nature of invading the lymphatic system and absence of a palpable tumor mass. Different from other metastatic breast cancer cells, IBC cells invade by forming tumor spheroids that retain E-cadherin-based cell-cell adhesions. Herein we describe the potential of the medicinal mushroom Ganoderma lucidum (Reishi) as an attractive candidate for anti-IBC therapy. Reishi contains biological compounds that are cytotoxic against cancer cells. We report the effects of Reishi on viability, apoptosis, invasion, and its mechanism of action in IBC cells (SUM-149). Results show that Reishi selectively inhibits cancer cell viability although it does not affect the viability of noncancerous mammary epithelial cells. Apoptosis induction is consistent with decreased cell viability. Reishi inhibits cell invasion and disrupts the cell spheroids that are characteristic of the IBC invasive pathology. Reishi decreases the expression of genes involved in cancer cell survival and proliferation (BCL-2, TERT, PDGFB), and invasion and metastasis (MMP-9), whereas it increases the expression of IL8. Reishi reduces BCL-2, BCL-XL, E-cadherin, eIF4G, p120-catenin, and c-Myc protein expression and gelatinase activity. These findings suggest that Reishi is an effective anti-IBC therapeutic.

ErbB1/2 tyrosine kinase inhibitor mediates oxidative stress-induced apoptosis in inflammatory breast cancer cells

Overexpression of epidermal growth factor receptors (ErbB) is frequently seen in inflammatory breast cancer (IBC). Treatment with ErbB1/2-targeting agents (lapatinib) mediates tumor apoptosis by downregulating ErbB1/2 phosphorylation and downstream survival signaling. In this study, using carboxy-H(2)DCFDA, DHE, and MitoSOX Red to examine changes in hydrogen peroxide radicals, cytoplasmic and mitochondrial superoxide, respectively, we observed that GW583340 (a lapatinib-analog) increases reactive oxygen species (ROS) in two models of IBC (SUM149, SUM190) that are sensitive to ErbB1/2 blockade. This significant increase in ROS levels was similar to those generated by classical oxidative agents H(2)O(2) and paraquat. In contrast, minimal to basal levels of ROS were measured in a clonal population of GW583340-resistant IBC cells (rSUM149 and rSUM190). The GW583340-resistant IBC cells displayed increased SOD1, SOD2, and glutathione expression, which correlated with decreased sensitivity to the apoptotic-inducing effects of GW583340, H(2)O(2), and paraquat. The ROS increase and cell death in the GW583340-sensitive cells was reversed by simultaneous treatment with a superoxide dismutase (SOD) mimic. Additionally, overcoming the high levels of antioxidants using redox modulators induced apoptosis in the GW583340-resistant cells. Taken together, these data demonstrate a novel mechanism of lapatinib-analog-induced apoptosis and indicate that resistant cells have increased antioxidant potential, which can be overcome by treatment with SOD modulators.

p53, HER2 and tumor cell apoptosis correlate with clinical outcome after neoadjuvant bevacizumab plus chemotherapy in breast cancer

Bevacizumab, an antibody to vascular endothelial growth factor (VEGF), has been incorporated into chemotherapy regimens in the treatment of several cancer types including breast cancer. The aim of this study was to identify tumor and angiogenic factors that potentially associate with outcome. In a pilot trial, 21 patients with inflammatory breast cancer and locally advanced breast cancer received bevacizumab plus doxorubicin-docetaxel chemotherapy before surgery. Baseline p53, HER2, tumor apoptosis, Ki67, estrogen receptor (ER), VEGF-A, serum VEGF (sVEGF), VEGFR2-Y951 and microvessel density (MVD) were prospectively designed and determined by immunohistochemistry and enzyme-linked immunosorbent assay. Hazard ratios (HR) and 95% confidence intervals for survival and progression-free survival (PFS) were estimated using Cox proportional hazards analyses. With a median follow-up of 65.9 months, patients with low apoptosis or p53-negative tumors had significantly longer survival than those with high apoptosis or p53-positive tumors (median 61.5 vs. 20.2 months; HR 0.22; p=0.011 for apoptosis and median 59.6 vs. 24.2 months; HR 0.27; p=0.016 for p53). Low Ki67 versus high Ki67 exhibited a trend towards association with survival (median 57.1 vs. 17.3 months, HR 0.34, p=0.07). Patients with HER2-negative tumors had significantly longer PFS than those with HER2-positive tumors (median 31.2 vs. 9.4 months; HR 0.23; p=0.03). ER, VEGF-A, sVEGF, VEGFR2-Y951 and MVD were not significantly associated with outcome. Our data suggest that baseline p53, apoptosis and HER2 are each significantly associated with outcome in patients who received bevacizumab plus chemotherapy.

High-resolution comparative genomic hybridization of inflammatory breast cancer and identification of candidate genes

BACKGROUND

Inflammatory breast cancer (IBC) is an aggressive form of BC poorly defined at the molecular level. We compared the molecular portraits of 63 IBC and 134 non-IBC (nIBC) clinical samples.

METHODOLOGY/FINDINGS

Genomic imbalances of 49 IBCs and 124 nIBCs were determined using high-resolution array-comparative genomic hybridization, and mRNA expression profiles of 197 samples using whole-genome microarrays. Genomic profiles of IBCs were as heterogeneous as those of nIBCs, and globally relatively close. However, IBCs showed more frequent "complex" patterns and a higher percentage of genes with CNAs per sample. The number of altered regions was similar in both types, although some regions were altered more frequently and/or with higher amplitude in IBCs. Many genes were similarly altered in both types; however, more genes displayed recurrent amplifications in IBCs. The percentage of genes whose mRNA expression correlated with CNAs was similar in both types for the gained genes, but ∼7-fold lower in IBCs for the lost genes. Integrated analysis identified 24 potential candidate IBC-specific genes. Their combined expression accurately distinguished IBCs and nIBCS in an independent validation set, and retained an independent prognostic value in a series of 1,781 nIBCs, reinforcing the hypothesis for a link with IBC aggressiveness. Consistent with the hyperproliferative and invasive phenotype of IBC these genes are notably involved in protein translation, cell cycle, RNA processing and transcription, metabolism, and cell migration.

CONCLUSIONS

Our results suggest a higher genomic instability of IBC. We established the first repertory of DNA copy number alterations in this tumor, and provided a list of genes that may contribute to its aggressiveness and represent novel therapeutic targets.

Clinical proteomics of breast cancer

Despite the lifetimes that increased in breast cancers due to the the early screening programs and new therapeutic strategies, many cases still are being lost due to the metastatic relapses. For this reason, new approaches such as the proteomic techniques have currently become the prime objectives of breast cancer researches. Various omic-based techniques have been applied with increasing success to the molecular characterisation of breast tumours, which have resulted in a more detailed classification scheme and have produced clinical diagnostic tests that have been applied to both the prognosis and the prediction of outcome to the treatment. Implementation of the proteomics-based techniques is also seen as crucial if we are to develop a systems biology approach in the discovery of biomarkers of the early diagnosis, prognosis and prediction of the outcome of the breast cancer therapies. In this review, we discuss the studies that have been conducted thus far, for the discovery of diagnostic, prognostic and predictive biomarkers, and evaluate the potential of the discriminating proteins identified in this research for clinical use as breast cancer biomarkers.

Inflammatory breast cancer: the disease, the biology, the treatment

Inflammatory breast cancer (IBC) is a rare and aggressive form of invasive breast cancer accounting for 2.5% of all breast cancer cases. It is characterized by rapid progression, local and distant metastases, younger age of onset, and lower overall survival compared with other breast cancers. Historically, IBC is a lethal disease with less than a 5% survival rate beyond 5 years when treated with surgery or radiation therapy. Because of its rarity, IBC is often misdiagnosed as mastitis or generalized dermatitis. This review examines IBC's unique clinical presentation, pathology, epidemiology, imaging, and biology and details current multidisciplinary management of the disease, which comprises systemic therapy, surgery, and radiation therapy.

Angiogenesis, lymphangiogenesis, growth pattern, and tumor emboli in inflammatory breast cancer: a review of the current knowledge

This objective of the current review was to provide the reader with a comprehensive summary of the literature related to 3 important and inter-related features of the biology of inflammatory breast cancer (IBC): angiogenesis, lymphangiogenesis, and the formation of tumor emboli. Information derived from animal models of IBC as well as from translational studies using tissue samples of patients with IBC are discussed.

X-linked inhibitor of apoptosis protein inhibits apoptosis in inflammatory breast cancer cells with acquired resistance to an ErbB1/2 tyrosine kinase inhibitor

Inflammatory breast cancer (IBC) is a highly aggressive subtype of breast cancer that is often characterized by ErbB2 overexpression. ErbB2 targeting is clinically relevant using trastuzumab (anti-ErbB2 antibody) and lapatinib (small-molecule ErbB1/2 inhibitor). However, acquired resistance is a common outcome even in IBC patients who show an initial clinical response, which limits the efficacy of these agents. In the present study, using a clonal population of GW583340 (lapatinib analogue, ErbB1/2 inhibitor)-resistant IBC cells, we identified the overexpression of an antiapoptotic protein, X-linked inhibitor of apoptosis protein (XIAP), in acquired resistance to GW583340 in both ErbB2-overexpressing SUM190 and ErbB1-activated SUM149 cell lines derived from primary IBC tumors. A marked decrease in p-ErbB2, p-ErbB1, and downstream signaling was evident in the GW583340-resistant cells (rSUM190 and rSUM149) similar to parental counterparts treated with the drug, suggesting that the primary mechanism of action of GW583340 was not compromised in resistant cells. However, rSUM190 and rSUM149 cells growing in GW583340 had significant XIAP overexpression and resistance to GW583340-mediated apoptosis. Additionally, stable XIAP overexpression using a lentiviral system reversed sensitivity to GW583340 in parental cells. The observed overexpression was identified to be caused by IRES-mediated XIAP translation. XIAP downregulation in rSUM190 and rSUM149 cells using a small-molecule inhibitor (embelin), which abrogates the XIAP/procaspase-9 interaction, resulted in decreased viability, showing that XIAP is required for survival of cells with acquired resistance to GW583340. These studies establish the feasibility of development of an XIAP inhibitor that potentiates apoptosis for use in IBC patients with resistance to ErbB2-targeting agents.

Inflammatory breast cancer

Inflammatory breast cancer (IBC) represents the most virulent form of breast cancer, characterized by involvement of the skin and rapid progression of the disease. Management involves careful coordination of all multidisciplinary modalities, including imaging, systemic chemotherapy, surgery, and radiation therapy. The use of neoadjuvant chemotherapy has contributed significantly to improvement in overall survival since the first descriptions of this entity and has made the role of locoregional therapy, including surgery and radiation critical to continued improvements in this disease. In this article, we examine the unique epidemiology and pathology of IBC and review the various treatment modalities noting the significance of a multimodality approach and delineating each of the specific components. Moreover, we briefly describe the current research in IBC that will hopefully contribute further to improve systemic therapies.

The impact of pregnancy on breast cancer outcomes in women<or=35 years

BACKGROUND

Some evidence suggests that women with pregnancy-associated breast cancers (PABC) have a worse outcome compared with historical controls. However, young age is a worse prognostic factor independently, and women with PABC tend to be young. The purpose of the current study was to compare locoregional recurrence (LRR), distant metastases (DM), and overall survival (OS) in young patients with PABC and non-PABC.

METHODS

Data for 668 breast cancers in 652 patients aged<or=35 years were retrospectively reviewed. One hundred four breast cancers (15.6%) were pregnancy-associated; 51 cancers developed during pregnancy and 53 within 1 year after pregnancy.

RESULTS

The median follow-up for all living patients was 114 months. Patients who developed PABC had more advanced T classification, N classification, and stage group (all P<.04) compared with patients with non-PABC. Patients with PABC had no statistically significant differences in 10-year rates of LRR (23.4% vs 19.2%; P=.47), DM (45.1% vs 38.9%; P=.40), or OS (64.6% vs 64.8%; P=.60) compared with patients with non-PABC. For those patients who developed breast cancer during pregnancy, any treatment intervention during pregnancy provided a trend toward improved OS compared with delaying evaluation and treatment until after delivery (78.7% vs 44.7%; P=.068).

CONCLUSIONS

Young patients with PABC had no statistically significant differences in LRR, DM, or OS compared with those with non-PABC; however, pregnancy contributed to a delay in breast cancer diagnosis, evaluation, and treatment. Primary care and reproductive physicians should be aggressive in the workup of breast symptoms in the pregnant population to expedite diagnosis and allow multidisciplinary treatment.

RelB NF-kappaB represses estrogen receptor alpha expression via induction of the zinc finger protein Blimp1

Aberrant constitutive expression of NF-kappaB subunits, reported in more than 90% of breast cancers and multiple other malignancies, plays pivotal roles in tumorigenesis. Higher RelB subunit expression was demonstrated in estrogen receptor alpha (ERalpha)-negative breast cancers versus ERalpha-positive ones, due in part to repression of RelB synthesis by ERalpha signaling. Notably, RelB promoted a more invasive phenotype in ERalpha-negative cancers via induction of the BCL2 gene. We report here that RelB reciprocally inhibits ERalpha synthesis in breast cancer cells, which contributes to a more migratory phenotype. Specifically, RelB is shown for the first time to induce expression of the zinc finger repressor protein Blimp1 (B-lymphocyte-induced maturation protein), the critical mediator of B- and T-cell development, which is transcribed from the PRDM1 gene. Blimp1 protein repressed ERalpha (ESR1) gene transcription. Commensurately higher Blimp1/PRDM1 expression was detected in ERalpha-negative breast cancer cells and primary breast tumors. Induction of PRDM1 gene expression was mediated by interaction of Bcl-2, localized in the mitochondria, with Ras. Thus, the induction of Blimp1 represents a novel mechanism whereby the RelB NF-kappaB subunit mediates repression, specifically of ERalpha, thereby promoting a more migratory phenotype.

The HER-2 receptor and breast cancer: ten years of targeted anti-HER-2 therapy and personalized medicine

The human epidermal growth factor receptor (HER-2) oncogene encodes a transmembrane tyrosine kinase receptor that has evolved as a major classifier of invasive breast cancer and target of therapy for the disease. The validation of the general prognostic significance of HER-2 gene amplification and protein overexpression in the absence of anti-HER-2 targeted therapy is discussed in a study of 107 published studies involving 39,730 patients, which produced an overall HER-2-positive rate of 22.2% and a mean relative risk for overall survival (OS) of 2.74. The issue of HER-2 status in primary versus metastatic breast cancer is considered along with a section on the features of metastatic HER-2-positive disease. The major marketed slide-based HER-2 testing approaches, immunohistochemistry, fluorescence in situ hybridization, and chromogenic in situ hybridization, are presented and contrasted in detail against the background of the published American Society of Clinical Oncology-College of American Pathologists guidelines for HER-2 testing. Testing issues, such as the impact of chromosome 17 polysomy and local versus central HER-2 testing, are also discussed. Emerging novel HER-2 testing techniques, including mRNA-based testing by real-time polymerase chain reaction and DNA microarray methods, HER-2 receptor dimerization, phosphorylated HER-2 receptors, and HER-2 status in circulating tumor cells, are also considered. A series of biomarkers potentially associated with resistance to trastuzumab is discussed with emphasis on the phosphatase and tensin homologue deleted on chromosome ten/Akt and insulin-like growth factor receptor pathways. The efficacy results for the more recently approved small molecule HER-1/HER-2 kinase inhibitor lapatinib are also presented along with a more limited review of markers of resistance for this agent. Additional topics in this section include combinations of both anti-HER-2 targeted therapies together as well as with novel agents including bevacizumab, everolimus, and tenespimycin. A series of novel HER-2-targeting agents is also presented, including pertuzumab, ertumaxomab, HER-2 vaccines, and recently discovered tyrosine kinase inhibitors. Biomarkers predictive of HER-2 targeted therapy toxicity are included, and the review concludes with a consideration of HER-2 status in the prediction of response to non-HER-2 targeted treatments including hormonal therapy, anthracyclines, and taxanes.

Automated image analysis in histopathology: a valuable tool in medical diagnostics

Virtual pathology, the process of assessing digital images of histological slides, is gaining momentum in today's laboratory environment. Indeed, digital image acquisition systems are becoming commonplace, and associated image analysis solutions are viewed by most as the next critical step in automated histological analysis. Here, we document the advances in the technology, with reference to past and current techniques in histological assessment. In addition, the demand for these technologies is analyzed with major players profiled. As there are several image analysis software programs focusing on the quantification of immunohistochemical staining, particular attention is paid to this application in this review. Oncology has been a primary target area for these approaches, with example studies in this therapeutic area being covered here. Toxicology-based image analysis solutions are also profiled as these are steadily increasing in popularity, especially within the pharmaceutical industry. Reinforced by the phenomenal growth of the virtual pathology field, it is envisioned that the market for automated image analysis tools will greatly expand over the next 10 years.

Different gene-expression profiles for the poorly differentiated carcinoma and the highly differentiated papillary adenocarcinoma in mammary glands support distinct metabolic pathways

BACKGROUND

Deregulation of Stat5 in the mammary gland of transgenic mice causes tumorigenesis. Poorly differentiated carcinoma and highly differentiated papillary adenocarcinoma tumors evolve. To distinguish the genes and elucidate the cellular processes and metabolic pathways utilized to preserve these phenotypes, gene-expression profiles were analyzed.

METHODS

Mammary tumors were excised from transgenic mice carrying a constitutively active variant of Stat5, or a Stat5 variant lacking s transactivation domain. These tumors displayed either the carcinoma or the papillary adenocarcinoma phenotypes. cRNAs, prepared from each tumor were hybridized to an Affymetrix GeneChip(R) Mouse Genome 430A 2.0 array. Gene-ontology analysis, hierarchical clustering and biological-pathway analysis were performed to distinct the two types of tumors. Histopathology and immunofluorescence staining complemented the comparison between the tumor phenotypes.

RESULTS

The nucleus-cytoskeleton-plasma membrane axis is a major target for differential gene expression between phenotypes. In the carcinoma, stronger expression of genes coding for specific integrins, cytoskeletal proteins and calcium-binding proteins highlight cell-adhesion and motility features of the tumor cells. This is supported by the higher expression of genes involved in O-glycan synthesis, TGF-beta, activin, their receptors and Smad3, as well as the Notch ligands and members of the gamma-secretase complex that enable Notch nuclear localization. The Wnt pathway was also a target for differential gene expression. Higher expression of genes encoding the degradation complex of the canonical pathway and limited TCF expression in the papillary adenocarcinoma result in membranal accumulation of beta-catenin, in contrast to its nuclear translocation in the carcinoma. Genes involved in cell-cycle arrest at G1 and response to DNA damage were more highly expressed in the papillary adenocarcinomas, as opposed to favored G2/M regulation in the carcinoma tumors.

CONCLUSION

At least six metabolic pathways support the morphological and functional differences between carcinomas and papillary adenocarcinomas. Differential gene-expression profiles favor cell adhesion, motility and proliferation in the carcinoma. Cell-cell contact, polarity, earlier cell-cycle arrest and DNA damage control are better displayed in the papillary adenocarcinoma.

Validation of tissue microarray technology in squamous cell carcinoma of the esophagus

Tissue microarray (TMA) technology has been developed to facilitate high-throughput immunohistochemical and in situ hybridization analysis of tissues by inserting small tissue biopsy cores into a single paraffin block. Several studies have revealed novel prognostic biomarkers in esophageal squamous cell carcinoma (ESCC) by means of TMA technology, although this technique has not yet been validated for these tumors. Because representativeness of the donor tissue cores may be a disadvantage compared to full sections, the aim of this study was to assess if TMA technology provides representative immunohistochemical results in ESCC. A TMA was constructed containing triplicate cores of 108 formalin-fixed, paraffin-embedded squamous cell carcinomas of the esophagus. The agreement in the differentiation grade and immunohistochemical staining scores of CK5/6, CK14, E-cadherin, Ki-67, and p53 between TMA cores and a subset of 64 randomly selected donor paraffin blocks was determined using kappa statistics. The concurrence between TMA cores and donor blocks was moderate for Ki-67 (κ = 0.42) and E-cadherin (κ = 0.47), substantial for differentiation grade (κ = 0.65) and CK14 (κ = 0.71), and almost perfect for p53 (κ = 0.86) and CK5/6 (κ = 0.93). TMA technology appears to be a valid method for immunohistochemical analysis of molecular markers in ESCC provided that the staining pattern in the tumor is homogeneous.

Clinical proteomics and breast cancer: strategies for diagnostic and therapeutic biomarker discovery

A major challenge of breast cancer research is the identification of accurate biomarkers that improve screening, early diagnosis, prediction of aggressiveness, and prediction of therapeutic response or toxicity, as well as the identification of new molecular therapeutic targets. The new proteomic techniques promise to be valuable for identifying such tissue and serum markers. The different techniques currently applied to clinical samples of breast cancer and the most important results obtained are summarized in this review.

Defining the molecular biology of inflammatory breast cancer

Inflammatory breast cancer (IBC) is a rare, but aggressive form of breast cancer. Despite the progress related to the introduction of primary combination chemotherapy (CT) to the multimodality treatment regimen, the prognosis of IBC remains poor with long-term survival inferior to 50%. Until recently, IBC remained understudied at the molecular level. In the past 10 years, advances have been made in the molecular characterization of the disease. Recently, the use of experimental models and new high-throughput molecular profiling technologies have led to the identification of genes or pathways potentially involved in disease development, which might represent new clinically relevant targets. The aim of this review is to present and discuss what is known about the biology of this particularly aggressive form of breast cancer and to discuss how this knowledge could improve its management.

Pathologic aspects of inflammatory breast cancer: part 2. Biologic insights into its aggressive phenotype

Inflammatory breast cancer (IBC) is the most aggressive and distinct form of primary breast cancer with a peculiar clinical presentation and dismal clinical outcome. This review addresses the pathologic aspects of this entity and discusses the molecular alterations involved in the highly malignant phenotype of IBC.

Inflammatory breast cancer: current understanding

PURPOSE OF REVIEW

Inflammatory breast cancer is a highly aggressive variant of locally advanced breast cancer that carries a significantly worse prognosis. The purpose of this review is to highlight recent advances in the molecular modus operandi of this particular form of breast cancer.

RECENT FINDINGS

Studies on tumor cell emboli, E-cadherin, chemokine receptors, steroid hormone receptor, angiogenesis, lymphangiogenesis and gene expression all suggest significant differences with noninflammatory breast cancer and are clearly in line with a different pathogenesis of the condition.

SUMMARY

This comprehensive review will hopefully allow for better treatment modalities with targeted approaches as suggested by the early data on anti-vascular endothelial growth factor treatment in inflammatory breast cancer.

Genetic Determinants of Aggressive Breast Cancer

The development and spread of breast and other human cancers are caused by the overexpression, mutation, and/or deletion of specific genes that drive these events. Finding genetic and molecular differences between cancerous and healthy cells can reveal the genetic determinants of cancer. This knowledge results in a better understanding of the carcinogenic process and improved predictive power, with implications for identifying new drug targets, designing novel therapies, and improving preclinical and clinical studies. We review the concepts of biomarker, genetic marker, and genetic determinant in cancer, with particular focus on the most aggressive and lethal form of breast cancer, termed inflammatory breast cancer (IBC). Using IBC as an example, we describe in detail the approaches to identify the genes that are responsible for-and not merely associated with-this disease.

Comparison of estrogen receptor results from pathology reports with results from central laboratory testing

We compared estrogen receptor (ER) assay results abstracted from pathology reports with ER results determined on the same specimens by a central laboratory with an immunohistochemical assay. Paraffin sections were cut from tissue microarrays containing 3093 breast cancer specimens from women enrolled in the Nurses' Health Study, 1851 of which had both pathology reports and tissue available for central laboratory testing. All sections were immunostained for ER at the same time. The original assays were biochemical for 1512 (81.7%) of the 1851 specimens, immunohistochemical for 336 (18.2%), and immunofluorescent for three (0.2%). ER results from pathology reports and repeat central laboratory testing were in agreement for 87.3% of specimens (1615 of the 1851 specimens; kappa statistic = 0.64, P < .001). When the comparison was restricted to the specimens for which the ER assays were originally performed by immunohistochemistry, the agreement rate increased to 92.3% of specimens (310 of the 336 specimens; kappa statistic = 0.78, P < .001). Thus, ER assay results from pathology reports appear to be a reasonable alternative to central laboratory ER testing for large, population-based studies of patients with breast cancer.

Markers of subtypes in inflammatory breast cancer studied by immunohistochemistry: prominent expression of P-cadherin

Background

Inflammatory breast cancer (IBC) is a distinct and aggressive form of locally-advanced breast cancer with high metastatic potential. In Tunisia, IBC is associated with a high death rate. Among the major molecular subtypes, basal breast carcinomas are poorly differentiated, have metastatic potential and poor prognosis, but respond relatively well to chemotherapy. The aim of this study was to determine the distribution of molecular subtypes in IBC and identify factors that may explain the poor prognosis of IBC.

Methods

To determine breast cancer subtypes we studied by immunohistochemistry the expression of 12 proteins in a series of 91 Tunisian IBC and 541 non-IBC deposited in tissue microarrays.

Results

We considered infiltrating ductal cases only. We found 33.8% of basal cases in IBC vs 15.9% in non-IBC (p < 0.001), 33.3% of ERBB2-overexpressing cases in IBC vs 14.5% in non-IBC (p < 0.001), and 29.3% of luminal cases in IBC vs 59.9% in non-IBC (p < 0.001). The most differentially-expressed protein between IBCs and non-IBCs was P-cadherin. P-cadherin expression was found in 75.9% of all IBC vs 48.2% of all non-IBC (p < 0.001), 95% of IBC vs 69% of non-IBC (p = 0.02) in basal cases, and 82% of IBC vs 43% of non-IBC (p < 0.001) in luminal cases. Logistic regression determined that the most discriminating markers between IBCs and non-IBCs were P-cadherin (OR = 4.9, p = 0.0019) MIB1 (OR = 3.6, p = 0.001), CK14 (OR = 2.7, p = 0.02), and ERBB2 (OR = 2.3, p = 0.06).

Conclusion

Tunisian IBCs are characterized by frequent basal and ERBB2 phenotypes. Surprisingly, luminal IBC also express the basal marker P-cadherin. This profile suggests a specificity that needs further investigation.

Trastuzumab signaling in ErbB2-overexpressing inflammatory breast cancer correlates with X-linked inhibitor of apoptosis protein expression

Inflammatory breast cancer (IBC) patients show poor survival and a significant incidence of epidermal growth factor receptor-2 (ErbB2) overexpression. A distinct mechanism involving increased expression of X-linked inhibitor of apoptosis protein (XIAP) and survivin, key members of the inhibitor of apoptosis protein (IAP) family, was observed post-trastuzumab (an ErbB2 monoclonal antibody) treatment in an ErbB2-overexpressing, estrogen receptor negative, IBC cellular model, SUM190PT, isolated from a primary IBC tumor. In contrast, a decrease in the IAP expression was observed in the non-IBC, ErbB2-overexpressing SKBR3 cells in which trastuzumab treatment also decreased p-AKT and cell viability. Further, in SUM190PT cells, therapeutic sensitivity to GW583340 (a dual epidermal growth factor receptor/ErbB2 kinase inhibitor) corresponded with XIAP down-regulation and abrogation of XIAP inhibition on active caspase-9 release. Specific small interfering RNA-mediated XIAP inhibition in combination with trastuzumab caused decrease in inactive procaspase-9 and inhibition of p-AKT corresponding with 45% to 50% decrease in cell viability in the SUM190PT cells, which have high steady-state p-AKT levels. Further, embelin, a small-molecule inhibitor that abrogates binding of XIAP to procaspase-9, caused significant decrease in SUM190PT viability. However, embelin in combination with trastuzumab failed to affect SUM190PT viability because it has no direct effect on XIAP, which is induced by trastuzumab treatment. These data have identified a novel functional link between ErbB2 signaling and antiapoptotic pathway mediated by XIAP. Blockade of the IAP antiapoptotic pathway alone or in combination would be an attractive strategy in IBC therapy.

RhoC GTPase expression as a potential marker of lymph node metastasis in squamous cell carcinomas of the head and neck

PURPOSE

Survival rates for squamous cell carcinoma of the head and neck (SCCHN) have remained unchanged for several decades due to local tumor recurrences as well as regional and distant metastases. Recent evidence has shown that RhoC GTPase is overexpressed in stages III and IV regionally metastatic SCCHN compared with stages I and II localized disease. This study evaluated the expression of RhoC in head and neck carcinoma and investigated the prognostic use of this marker on a large cohort of previously untreated patients with SCCHN.

EXPERIMENTAL DESIGN

Standard Western blot techniques were used to evaluate RhoC protein expression in nine established head and neck cancer cell lines and in normal oral epithelium. In vivo expression of RhoC in metastatic and nonmetastatic SCCHN was investigated using immunohistochemical analysis on a tissue microarray composed of 113 independent tumor samples. RhoC expression was analyzed as it related to clinical and pathologic variables of interest.

RESULTS

Levels of RhoC protein were increased in the SCCHN cell lines compared with normal oral epithelium. The in vivo expression of RhoC correlated with advanced clinical stage and lymph node metastases for the entire patient cohort as well as in small primary tumors (T(1) and T(2)).

CONCLUSIONS

This study is the first to examine the expression of RhoC GTPase protein in SCCHN and normal squamous epithelium. It is clear from the results that RhoC is a specific marker of lymph node metastases in patients with this challenging form of carcinoma. RhoC levels seem to identify a subset of patients with early tumor stage primary tumors and high metastatic potential that might benefit from more aggressive therapy. Through continued investigation, blockade of RhoC activity may be a potential target in the development of novel strategies for treating metastases of head and neck cancer.

Molecular epidemiologic features of inflammatory breast cancer: a comparison between Egyptian and US patients

BACKGROUND

Inflammatory breast cancer (IBC) is a lethal form of breast cancer with unknown etiology. A higher frequency of IBC and a more aggressive IBC phenotype was reported in Egypt than in the United States. This difference in disease frequency and presentation might be related to molecular epidemiologic factors.

METHODS

We used tumor blocks and demographic, epidemiologic, and clinical data of 48 IBC patients from Egypt and 12 patients from the United States. We counted tumor emboli in tumors before and after immunohistochemical staining with lymphatic vessel endothelial receptor-1 (LYVE-1), and measured the expression of RhoC GTPase protein in the two groups.

RESULTS

Erythema, edema, and peau d'orange were found in 77% of the Egyptian patients as compared with 29% found in the US patients (P=0.02). The number of tumor emboli was significantly higher in tumors from Egypt (mean+/-SD, 14.1+/-14.0) than in the tumors from the United States (5.0+/-4.0, P=0.01). The number of tumor emboli in LYVE-1 positive vessels was higher in tumors from Egypt (3.5+/-2.8) than tumors from the United States (1.6+/-0.5, P=0.15). We detected a high level of RhoC in 87% of the tumors from Egypt and 14% of the tumors from the United States (P=0.0003).

CONCLUSION

Patients from Egypt have a more aggressive form of IBC than those in the United States. Our analysis of IBC patients shows that distinct molecular phenotypes can be found when these two study populations are compared. Future studies should explore the epidemiologic and environmental exposures and the genetic factors that might lead to the different clinical and molecular features of IBC in patients from these two countries.

Nuclear factor-kappaB signature of inflammatory breast cancer by cDNA microarray validated by quantitative real-time reverse transcription-PCR, immunohistochemistry, and nuclear factor-kappaB DNA-binding

PURPOSE

Inflammatory breast cancer (IBC) is the most aggressive form of locally advanced breast cancer with high metastatic potential. In a previous study, we showed that IBC is a different form of breast cancer compared with non-IBC by cDNA microarray analysis. A list of 756 genes with significant expression differences between IBC and non-IBC was identified. In-depth functional analysis revealed the presence of a high number of nuclear factor-kappaB (NF-kappaB) target genes with elevated expression in IBC versus non-IBC. This led to the hypothesis that NF-kappaB contributes to the phenotype of IBC. The aim of the present study was to further investigate the role of NF-kappaB in IBC.

EXPERIMENTAL DESIGN

Immunohistochemistry and NF-kappaB DNA-binding experiments were done for all NF-kappaB subunits (RelA, RelB, cRel, NFkB1, and NFkB2) using IBC and non-IBC specimens. Transcriptionally active NF-kappaB dimers were identified by means of coexpression analysis. In addition, quantitative real-time reverse transcription-PCR for eight NF-kappaB target genes, selected upon a significant, 3-fold gene expression difference between IBC and non-IBC by cDNA microarray analysis, was done.

RESULTS

We found a significant overexpression for all of eight selected NF-kappaB target genes in IBC compared with non-IBC by quantitative real-time reverse transcription-PCR. In addition, we found a statistically elevated number of immunostained nuclei in IBC compared with non-IBC for RelB (P = 0.038) and NFkB1 (P < 0.001). Immunohistochemical data were further validated by NF-kappaB DNA-binding experiments. Significant correlations between immunohistochemical data and NF-kappaB DNA binding for RelA, RelB, NFkB1, and NFkB2 were found. Transcriptionally active NF-kappaB dimers, composed of specific combinations of NF-kappaB family members, were found in 19 of 44 IBC specimens compared with 2 of 45 non-IBC specimens (P < 0.001). In addition, we found evidence for an estrogen receptor (ER)-mediated inhibition of the NF-kappaB signaling pathway. NF-kappaB target genes were significantly elevated in ER- versus ER+ breast tumors. Also, the amount of immunostained nuclei for RelB (P = 0.025) and NFkB1 (P = 0.031) was higher in ER- breast tumors versus ER+ breast tumors.

CONCLUSIONS

The NF-kappaB transcription factor pathway probably contributes to the phenotype of IBC and possibly offers new options for treatment of patients diagnosed with this aggressive form of breast cancer.

Influence of VEGF-A gene variation and protein levels in breast cancer susceptibility and severity

Vascular endothelial growth factor-A (VEGF-A) plays an important role in tumour angiogenesis and cancer progression. VEGF gene variation may influence VEGF levels and therefore cancer susceptibility and progression. We studied the role of VEGF single nucleotide polymorphisms and haplotypes in breast cancer susceptibility and severity. We also studied the relationships of VEGF SNPs with circulating VEGF levels in healthy volunteers and protein expression in breast cancers. Single nucleotide polymorphisms (SNPs) in the regulatory regions of the VEGF gene were genotyped by high throughput methods in approximately 500 breast cancer cases and 500 appropriate controls. Haplotype frequencies were inferred using methods based on the Expectation Maximisation algorithm. The effect of VEGF genotypes on serum and plasma VEGF levels were studied in another cohort of healthy individuals. A semi-quantitative assessment of VEGF protein expression on tissue micro arrays (TMA) constructed from approximately 300 breast cancer samples was performed and compared with VEGF genotypes and with histopathological parameters and survival in breast cancer. The -460T/+405C/-7C/936C haplotype in the VEGF gene was found to be associated with decreased breast cancer risk (p = 0.029). The -7C>T polymorphism may influence overall breast cancer survival (p = 0.027). Individual polymorphisms however did not affect breast cancer susceptibility. There was no association between the individual polymorphisms and circulating VEGF levels in healthy volunteers and VEGF expression on the breast cancer micro array. VEGF expression in breast cancers was however associated with high grade (p = 0.002) and ER negative tumours (p = 0.03).

Prognostic significance of overexpression and phosphorylation of epidermal growth factor receptor (EGFR) and the presence of truncated EGFRvIII in locoregionally advanced breast cancer

PURPOSE

The prognostic value of the epidermal growth factor receptor (EGFR) in breast cancer and more specifically, in patients with locoregionally advanced disease, is still undefined. We hypothesized that EGFR status plays a major prognostic role in this setting, through expression, activation, or the presence of its mutated variant EGFRvIII.

PATIENTS AND METHODS

We reviewed tumor samples of 225 patients treated uniformly in prospective trials of high-dose chemotherapy for four to nine positive axillary nodes, > or = 10 positive nodes, or inflammatory carcinoma, and observed for a median of 9 years (range, 3 to 13 years). We analyzed the effect on outcome of expression of EGFR, phosphorylated EGFR (phospho-EGFR), and EGFRvIII, as studied by immunohistochemistry.

RESULTS

EGFR expression, phospho-EGFR, and mutated EGFRvIII were detected in 43%, 54%, and 4% of the patients, respectively. EGFR expression correlated with negative hormone receptor status, and was associated with significantly worse relapse-free survival (59% v 79%; P < .001) and overall survival (61% v 81%; P = .001) than no expression. There was no association of phospho-EGFR or EGFRvIII with outcome. Multivariate models confirmed the prognostic effect of EGFR independent of other known prognostic variables in this population. The prognostic value of EGFR was most prominent in the human epidermal growth factor receptor 2 (HER-2) -positive and the estrogen receptor/progesterone receptor-negative subgroups.

CONCLUSION

EGFR expression, but not phospho-EGFR or EGFRvIII expression, is an independent adverse prognostic factor in patients with high-risk primary breast cancer, particularly when it is coexpressed with HER-2. Our results suggest the potential benefit of dual EGFR/HER-2 receptor targeting in this setting.