Molecular Classification Of Breast Cancer Research Articles

Abstract P1-01-09: Molecular Detection of Sentinel Lymph Node Metastases in Breast Cancer Patients: Correlation between Cytokeratin 19 mRNA Copy Number Detected by One Step Nucleic Acid Amplification (OSNA) and Risk of Metastases in Axillary Lymph Nodes

Abstract Background: The accuracy of the OSNA assay for metastases detection in sentinel lymph nodes (SLNs) has recently been validated in our Institute and adopted as an intra-operative test for breast cancer (BC) patient management. The aims of this study in a series of early BC patients, were: 1) to correlate the copy numbers of cytokeratin 19 (CK19) mRNA with the size of nodal metastases and with the risk of additional disease in non-sentinel lymph nodes (NSLNs); 2) to investigate the relationship between SLN status with OSNA method, and conventional bio-pathological factors taking into account the molecular BC classification: luminal A, luminal B, HER2 subtype, and triple-negative; 3) to identify a subgroup of patients with positive SLN with higher risk of NSLNs metastatic involvement. Material and Methods: 750 SLNs from 580 patients were clinically processed using both OSNA assay and post-operative histology. The results of these two methods were then compared. The correlation between the size of metastases and the copy numbers of CK19 mRNA was calculated using the Spearman correlation coefficient. Complementary axillary lymph node dissection (ALND) was performed concurrently in case of OSNA assay positivity and the probability of having a positive lymph node axillary dissection was calculated by the unconditional logistic regression model. This series of BC patients were divided into four main subtypes taking in account the BC classification based on the immunohistochemistry phenotypic patterns. Results: OSNA positivity was reported in 24.6% of the patients for a sensitivity of 94.2%. Considering the 145 patients with SLN positivity the size of metastatic foci was significantly correlated to the copy numbers of CK19 mRNA. The complex relationships among the bio-pathological variables analyzed by multiple correspondence analysis (MCA) showed that the metastatic involvement of NSLNs is associated with SLNs with a high copy numbers of CK19 mRNA and HER2 subtype tumors. OSNA specificity (95%) and negative predictive value (98.4%) clearly demonstrated its reliability to guide ALND decision. Conclusions: Our results showed that OSNA is an excellent method for the detection of metastases in SLN and its adoption in our clinical practice has determined a significant improvement in the diagnosis of metastatic BC. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-01-09.

The anti-diabetic drug metformin suppresses the metastasis-associated protein CD24 in MDA-MB-468 triple-negative breast cancer cells

CD24, a mucin-like adhesion molecule that enhances the metastatic potential of malignant cells, has been suggested to be a marker of poor prognosis in breast carcinomas. The tumor-initiating potential of CD44posCD24pos cell populations has been recently recognized and, accordingly, distant metastases are largely composed of CD24-positive cells in breast cancer patients refractory to treatment. Therefore, new therapeutic strategies aimed at down-regulating CD24 may negatively regulate the dissemination of tumor cells and formation of metastasis. Here, we reveal that suppression of CD24 protein expression is a crucial event in the molecular mechanisms underlying the growth-inhibitory effects of the anti-diabetic drug metformin in MDA-MB-468 triple-negative (basal-like) breast cancer cells. First, we confirmed that, among the different molecular classes of breast cancer, basal-like breast cancer cells were significantly more sensitive to the growth-inhibitory effects of metformin. Second, we observed a positive correlation between the growth inhibitory activity of metformin and the relative enrichment in cells bearing the CD44posCD24pos immunophenotype. Third, high-content indirect immunofluorescence imaging assays revealed that CD24 protein levels were drastically decreased in the presence of growth-inhibitory concentrations of metformin. Fourth, to preliminary assess the clinical relevance of metformin's anti-CD24 effects we took advantage of the recently developed ROCK online interface (http://rock.icr.ac.uk/), a publicly accessible portal that allows rapid integration of breast cancer functional and molecular profiling datasets. When we evaluated the impact of CD24 expression on distant metastasis-free survival (DMFS) in microarray gene expression breast cancer datasets, Kaplan-Meier survival analyses and log-rank tests comparing DMSF for CD24-high and CD24-low breast carcinomas revealed that patients with CD24-high tumors tended to have a shorter DMFS. These findings, altogether, suggest that the ability of metformin to suppress the oncogene, metastasis promoter and breast cancer stem cell marker CD24 may open a novel molecular avenue in the therapeutic management of highly-metastastic subgroups of triple-negative (basal-like) breast cancers naturally enriched with CD44posCD24pos tumor-initiating cell populations.

Marqueurs pronostiques et prédictifs de réponse aux traitements des cancers du sein

Breast cancer heterogeneity has been deciphered during the last decade thanks to the use of high-throughput tools. A major clinical concern is the determination of the metastatic risk of the tumours (prognostic factor), but also the optimal choice of the treatment for a given patient and tumour (predictive factor). A significance advance has been obtained from the description of a novel molecular classification of breast cancers. This allowed a refinement in the determination of tumour groups displaying different prognoses. Presently, numerous gene signatures have been published and some of them are on the market, at least in the United States, but prospective validation studies are still ongoing. After a major enthusiasm, numerous questions have been raised, concerning especially the stability of these signatures. An improved knowledge of these limits is also an important factor for an optimal use of these data. It can be concluded that it should be possible to improve patients’ care by integrating molecular and clinicopathologic data in a common approach on the one hand, and to further develop new biomarkers predictive of therapeutic efficacy on the other hand.

In Situ Proteomic Analysis of Human Breast Cancer Epithelial Cells Using Laser Capture Microdissection: Annotation by Protein Set Enrichment Analysis and Gene Ontology

Identification of molecular signatures that allow detection of the transition from normal breast epithelial cells to malignant invasive cells is a critical component in the development of diagnostic, therapeutic, and preventative strategies for human breast cancer. Substantial efforts have been devoted to deciphering breast cancer etiology at the genome level, but only a limited number of studies have appeared at the proteome level. In this work, we compared individual in situ proteome profiles of nonpatient matched nine noncancerous, normal breast epithelial (NBE) samples with nine estrogen receptor (ER)-positive (luminal subtype), invasive malignant breast epithelial (MBE) samples by combining laser capture microdissection (LCM) and quantitative shotgun proteomics. A total of 12,970 unique peptides were identified from the 18 samples, and 1623 proteins were selected for quantitative analysis using spectral index (SpI) as a measure of protein abundance. A total of 298 proteins were differentially expressed between NBE and MBE at 95% confidence level, and this differential expression correlated well with immunohistochemistry (IHC) results reported in the Human Protein Atlas (HPA) database. To assess pathway level patterns in the observed expression changes, we developed protein set enrichment analysis (PSEA), a modification of a well-known approach in gene expression analysis, Gene Set Enrichment Analysis (GSEA). Unlike single gene-based functional term enrichment analyses that only examines pathway overrepresentation of proteins above a given significance threshold, PSEA applies a weighted running sum statistic to the entire expression data to discover significantly enriched protein groups. Application of PSEA to the expression data in this study revealed not only well-known ER-dependent and cellular morphology-dependent protein abundance changes, but also significant alterations of downstream targets for multiple transcription factors (TFs), suggesting a role for specific gene regulatory pathways in breast tumorigenesis. A parallel GOMiner analysis revealed both confirmatory and complementary data to PSEA. The combination of the two annotation approaches yielded extensive biological feature mapping for in depth analysis of the quantitative proteomic data.

Gene-expression profiling in breast cancer: bespoke cancer therapy or more fiction than science?

Breast cancer is the most common life threatening malignancy in women. Despite advances in molecular therapeutics, many patients with apparently early stage and curable disease still develop progressive and fatal systemic disease. Haffty et al. [1] demonstrated that despite conservative surgery and radiation followed by administration of chemotherapy in early-stage (T1 tumours) breast cancer patients, the distant metastasis-free survival rate was 71% at 5 years in patients with triple negative disease and 83% at 5 years in non-triple negative. These patients have potentially been under-staged by conventional staging, and therefore may not have received optimum therapy due to their misleading clinical disease profile. Conversely, patients receiving systemic therapy may not derive any additional benefit. Breast cancer is an intricate genetic milieu characterised by numerous molecular alterations that prevents standardising therapeutic strategies to all patients. Until recently, it has been difficult to accurately profile and predict the biological properties and clinical behaviour of breast tumours, however, with the development of DNA microarray technology, it is now possible to analyse the RNA expression of several thousands of genes simultaneously. The clinical application of this technology has the potential to signal a paradigm shift in patient selection for systemic therapy. First, it provided a new molecular classification of breast cancer. This classification was proposed by Perou et al. [2], and subdivided breast cancers into four classes. Luminal-A cancers are ER-positive and mostly low grade. Luminal-B cancers are also ER-positive but tend to be high grade. Basal-like cancers are triple negative and Her-2-like cancers are Her-2 positive and usually ER negative. Currently, there are a number of validated commercially available multigene assays that identify expression of distinct sets of genes in breast cancer: Mammaprint (Agendia), Oncotype DX (Genomic Health), MapQuant and H/I (AvariaDX) (see Table 1 for comparison of assays). Mammaprint uses DNA microarray technology, whereas Oncotype DX and H/I use real time PCR based assays. These assays accurately predict the potential for disease recurrence and enhance patient selection for chemotherapeutic strategies. Mammaprint uses a 70-gene predictor and is involved in the MINDACT (Microarray In Node negative Disease may Avoid ChemoTherapy) trial [3]. The objective is to administer chemotherapy to patients deemed at high risk of recurrence, and hormonal therapy only to low risk patients, as determined by the Mammaprint gene profile. Having recruited large numbers of patients who are stratified based on the clinical and pathological risks, it is hoped that this study will provide important information regarding the prognostic capabilities of the Mammaprint test and also validate its use in identifying women associated with improved survival. Previously, Buyse et al. [4] demonstrated that Mammaprint outperformed Adjuvant Online in predicting survival in an independent group of patients. Unfortunately, however, a major disadvantage of Mammaprint is that it requires fresh tissue for analysis, which may make its clinical integration difficult. The Oncotype DX and H/I assay, however, can use archival tissue (tissue from original biopsy) and may be more readily applied to the clinical setting. By analysing the expression of 21 known genes, Oncotype DX accurately determined the prognostic outcome in hormone receptor positive cancers post adjuvant tamoxifen in a retrospective cohort of 668 M. Barry M. R. Kell (&) Eccles Breast Screening Unit, Mater Misericordiae University Hospital, Eccles St, Dublin 7, Ireland e-mail: malcolm.kell@breastcheck.ie

Microarray-Based Gene Expression Profiling for Molecular Classification of Breast Cancer and Identification of New Targets for Therapy

Basal-like breast cancers represent approximately 15%–20% of all breast carcinomas, are aggressive, have variable responses to chemotherapy, and associated with poor clinical outcome. The molecular mechanisms governing the biological behavior of basal-like breast cancers are not well understood. Hence, it is difficult to predict which chemotherapeutics are most likely to be effective and to determine appropriate management strategies for individual patients. Transcriptomic analysis may allow further stratification of basal-like breast cancers enabling prediction of 1) cancer recurrence after surgery; 2) likelihood of metastatic spread; 3) probable tissue sites for metastatic spread; and 4) responses to specific therapies and treatment modalities. Furthermore, careful examination of microarray-based gene expression profiles may identify new molecular targets (or pathways) for the development of targeted therapeutics. Targeted therapies may prove to be more efficacious in basal-like breast cancer treatment than the cytotoxic chemotherapeutics currently employed.

Use of ER/PR/HER2 subtypes in conjunction with the 2007 St Gallen Consensus Statement for early breast cancer

BackgroundThe 2007 St Gallen international expert consensus statement describes three risk categories and provides recommendations for treatment of early breast cancer. The set of recommendations on how to best treat primary breast cancer is recognized and used by clinicians worldwide. We now examine the variability of five-year survival of the 2007 St Gallen Risk Classifications utilizing the ER/PR/HER2 subtypes.MethodsUsing the population-based California Cancer Registry, 114,786 incident cases of Stages 1-3 invasive breast cancer diagnosed between 2000 and 2006 were identified. Cases were assigned to Low, Intermediate, or High Risk categories. Five-year-relative survival was computed for the three St Gallen risk categories and for the ER/PR/HER2 subtypes for further differentiation.Results and DiscussionThere were 9,124 (13%) cases classified as Low Risk, 44,234 (65%) cases as Intermediate Risk, and 14,340 (21%) as High Risk. Within the Intermediate Risk group, 33,735 (76%) were node-negative (Intermediate Risk 2) and 10,499 (24%) were node-positive (Intermediate Risk 3). For the High Risk group, 6,149 (43%) had 1 to 3 positive axillary lymph nodes (High Risk 4) and 8,191 (57%) had four or more positive lymph nodes (High Risk 5).Using five-year relative survival as the principal criterion, we found the following: a) There was very little difference between the Low Risk and Intermediate Risk categories; b) Use of the ER/PR/HER2 subtypes within the Intermediate and High Risk categories separated each into a group with better five-year survival (ER-positive) and a group with worse survival (ER-negative), irrespective of HER2-status; c) The heterogeneity of the High Risk category was most evident when one examined the ER/PR/HER2 subtypes with four or more positive axillary lymph nodes; (d) HER2-positivity did not always translate to worse survival, as noted when one compared the triple positive subtype (ER+/PR+/HER2+) to the triple negative subtype (ER-/PR-/HER2-); and (e) ER-negativity appeared to be a stronger predictor of poor survival than HER2-positivity.ConclusionThe use of ER/PR/HER2 subtype highlights the marked heterogeneity of the Intermediate and High Risk categories of the 2007 St Gallen statements. The use of ER/PR/HER2 subtypes and correlation with molecular classification of breast cancer is recommended.

Protein expression profile and prevalence pattern of the molecular classes of breast cancer--a Saudi population based study.

BackgroundBreast cancer is not a single entity but a diverse group of entities. Advances in gene expression profiling and immunohistochemistry as its surrogate marker have led to the unmasking of new breast cancer molecular subtypes, resulting in the emergence of more elaborate classification systems that are therapeutically and prognostically more predictive. Molecular class distribution across various ethnic groups may also reveal variations that can lead to different clinical outcomes in different populations.MethodsWe aimed to analyze the spectrum of molecular subtypes present in the Saudi population. ER, PR, HER2, EGFR and CK5/6 were used as surrogate markers for gene expression profiling to classify 231 breast cancer specimens. Correlation of each molecular class with Ki-67 proliferation index, p53 mutation status, histologic type and grade of the tumor was also carried out.ResultsOut of 231 cases 9 (3.9%) were classified as luminal A (strong ER +ve, PR +ve or -ve), 37 (16%) as luminal B (weak to moderate ER +ve, and/or PR +ve), 40 (17.3%) as HER2+ (strong or moderately positive HER 2 with confirmation by silver enhanced in-situ hybridization) and 23 (10%) as basal (CK5/6 or EGFR +ve). Co-positivity of different markers in varied patterns was seen in 23 (10%) of cases which were grouped into a hybrid category comprising luminal B-HER2, HER2-basal and luminal-basal hybrids. Ninety nine (42.8%) of the tumors were negative for all five immunohistochemical markers and were labelled as unclassified (penta negative). A high Ki-67 proliferation index was seen in basal (p = 0.007) followed by HER2+ class. Overexpression of p53 was predominantly seen in HER2 + (p = 0.001) followed by the basal group of tumors. A strong correlation was noted between invasive lobular carcinoma and hormone receptor expression with 8 out of 9 lobular carcinoma cases (88.9%) classifiable as luminal cancers. Otherwise, there was no association between the molecular class and the histologic type or grade of the tumor.ConclusionsSubtyping by use of this immunohistochemical panel revealed a prevalence pattern that is unique to our population; luminal tumors comprised only 19.9%, and the unclassified group (penta negative) 42.8%, a distribution which is distinctive to our population and in contrast with all Western studies. The presence of a predominant unclassified group also suggests that the currently used molecular analytic spectrum may not completely encompass all molecular classes and there is a need to further refine and develop the existing classification systems.

Pathology evaluation of sentinel lymph nodes in breast cancer: protocol recommendations and rationale

Sentinel lymph nodes (SLN) are more likely to contain metastatic breast carcinoma than non-SLNs. The limited number of SLNs compared with an axillary dissection has prompted more comprehensive lymph node analysis increasing detection of micrometastases. National data show that many women previously classified node negative are now classified minimally node positive. As a result, our nodal classification and cancer staging have evolved to recognize the continuum of nodal tumor burden rather than a simplistic dichotomous stratification. It is quite clear that the more sections we evaluate from SLNs the more metastases we identify; however, it is impractical to expect the practicing pathologist to mount, stain, and microscopically examine every section through the SLN paraffin blocks. Despite recommendations from the College of American Pathologists and the American Society of Clinical Oncology, heterogeneity in the approach to SLN evaluation exists. What is needed is adherence to a standardized evaluation protocol. The most important aspect of the sentinel node examination is careful attention to slicing the SLN no thicker than 2.0 mm and correct embedding of the slices to assure we identify all macrometastases larger than 2.0 mm. A single section from blocks prepared in this manner will identify all macrometastases present but smaller metastases will be missed. The prognostic significance of these missed micrometastases is still being evaluated as we await SLN outcome studies. In the context of the new molecular classification of breast cancer, subgroups may be identified where detection of micrometastases has clinical significance. It is critical that both clinicians and pathologists understand there is a random component to micrometastasis distribution within the three-dimensional paraffin tissue blocks. If we ultimately adopt more comprehensive microscopic evaluation of SLNs, the candidate sampling strategies need to be carefully considered in the context of statistically valid sampling strategies.

Abstract 3285: Phenotypic characterization of circulating tumor cells (CTCs) in triple negative breast cancer patients

Abstract Background: Molecular classification of breast cancer revealed that there are five different subtypes related to clinical outcome:. luminal A, luminal B, normal-like, ERBB2-positive and basal-like. Triple negative patients (ER-negative, PR-negative, HER2-negative) belong to the basal-like subtype. Their tumors commonly express EGFR and are associated with poor prognosis. Circulating Tumor Cells (CTCs) have been proposed as a “real time liquid biopsy” in breast cancer patients. CTCs are associated with disease relapse and could serve as a target for molecular cancer therapies. The aim of the present study was, for the first time, the phenotypic characterization of CTCs in triple negative breast cancer patients. Methods: We evaluated peripheral blood mononuclear cells (PBMC) cytospins from 40 triple negative patients and found CTCs in thirty one of them (15 early and 16 metastatic). The expression of Cytokeratins (CK), Estrogens Receptor (ER), Progesterone Receptor (PR), Epidermal Growth Factor Receptor (EGFR) and Human Epidermal Growth Factor Receptor (HER2) in CTCs was assessed using double immunofluorescent staining and confocal laser scanning microscopy and the Ariol system. PBMCs were stained with a monoclonal A45-B/B3 pancytokeratin antibody in combination with ER, PR, EGFR or HER2 antibodies, respectively. Results: Our results demonstrated that ER, PR, EGFR and HER2 were expressed in 58%, 45%, 55% and 58% of the examined CK-positive patients. The respective proportions for early versus (vs) metastatic patients were 67% vs 50% for ER, 53% vs 38% for PR, 60% vs 44% for EGFR and 60% vs 56% for HER2. In addition ER, PR, EGFR and HER2 were expressed in 5.6%, 79.7%, 80.7% and 13.4%, respectively, of the total examined CTCs. Triple staining experiments with the Ariol system revealed no co-expression of CK/EGFR/ER in CTCs; however, there was only one patient with CTCs co-expressing CK/HER2/ER. Conclusions: ER is expressed but in a minority of CTCs in triple negative breast cancer patients though the majority of CTCs revealed expression of PR and EGFR. However the clinical significance of these findings remain unknown and need further evaluation. Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3285.

Expresión de p63 y citoqueratina 5/6 en los diferentes tipos moleculares del carcinoma de mama

Background: Breast cancer is a heterogeneous group of tumors. DNA microarray profiling studies have led to the classification of invasive breast carcinoma called molecular classes. AIMS: To study the expression of p63 and cytokeratin (CK) 5/6 in invasive ductal carcinomas and their relationship to the different molecular classes, especially the basal like subgroup. Methods: Immunohistochemistry with the antibodies p63 and CK5/6 was performed in 200 samples of invasive ductal carcinomas with no other specification. Each case had previous results of estrogen and progesterone receptor (ER, PR), and HER2. According to these data they were classified as luminal A, luminal B, HER2+ and basal like (triple negative). Results: p63 was expressed in 5 cases of HER2+ and 19 cases of basal like tumours (19.5%). There was a strong relationship between CK5/6 expression and basal like tumours (68.9%, p<0.0001), but it was also expressed in one luminal A, three luminal B and eight HER2+ cases. Conclusions: Not every triple negative tumors express basal markers. It is necesary to standarize the molecular classification of breast cancer and the panel of markers to use in its caracterization, especially for the basal like. © 2010 SEAP y SEC.

Combinatorial biomarker expression in breast cancer

Current clinical management of breast cancer relies on the availability of robust clinicopathological variables and few well-defined biological markers. Recent microarray-based expression profiling studies have emphasised the importance of the molecular portraits of breast cancer and the possibility of classifying breast cancer into biologically and molecularly distinct groups. Subsequent large scale immunohistochemical studies have demonstrated that the added value of studying the molecular biomarker expression in combination rather than individually. Oestrogen (ER) and progesterone (PR) receptors and HER2 are currently used in routine pathological assessment of breast cancer. Additional biomarkers such as proliferation markers and 'basal' markers are likely to be included in the future. A better understanding of the prognostic and predictive value of combinatorial assessment of biomarker expression could lead to improved breast cancer management in routine clinical practice and would add to our knowledge concerning the variation in behaviour and response to therapy. Here, we review the evidence on the value of assessing biomarker expression in breast cancer individually and in combination and its relation to the recent molecular classification of breast cancer.

NF-κB Activation in Breast Cancer Occurs Via Different Mechanisms in Triple Negative and HER2+ Tumors with Lymphocytic Infiltrate.

Abstract NF-κB transcription factors regulate expression of genes involved in immune response, inflammation, apoptosis and cancer. NF-κB is known to be regulated via two main mechanisms: (i) through the IκB kinase complex (via the canonical pathway), and (ii) through the IKKα and NIK kinases (via the alternative pathway). Recently, NF-κB has also been shown to be activated by the IKBKE kinase. In breast cancer the level of NF-κB was found elevated only in triple negative (basal) and in HER2+ tumors. Inhibition of NF-κB has been shown to block cell proliferation and tumor formation, and therefore, genes that activate NF-κB might be potential drug targets in the treatment of cancer. Our study aims to identify the mechanisms of activation of NF-κB in various breast cancer subtypes.We analyzed several breast cancer gene expression microarray datasets from public repositories (GSE 2034, 4922, 7390) and used our molecular classification of breast cancer proposed in (Can Res 2007 67: 10669-76) to identify the subtypes of breast cancer in which the NF-κB pathway is altered. The NF-κB activity was evaluated based on upstream and downstream events for the canonical and the alternative pathways, and quantified through a consensus of geneset enrichment scores. We found that the NF-κB downstream genes are upregulated only in triple negative (subtype basal BA) and Her2+ tumors having an immune signature provided by the presence of a lymphocytic infiltrate (subtype Her2I).In order to identify the pathways involved in NF-κB activation, we analyzed the expression of the upstream genes in the canonical, alternative, IKBKE and PI3K/AKT pathways. We found that AKT1 -- an AKT isoform that activates IKKα -- is overexpressed in Her2I, while other AKT isoforms, AKT2 and AKT3, are overexpressed in BA. PI3K is overexpressed in BA, but not in Her2I. We also found that PDK1, which phosphorylates and activates AKT, is overexpressed in Her2I but not in BA. TNFα -- an activator of the NF-κB canonical pathway -- was found overexpressed in BA. However, in BA the components of the IKK complex have low expression apart from IKKγ. IKBKE was found upregulated in both BA and Her2I subtypes.In Her2I, the absence of high expression of TRAF2/5, which recruits the IKK complex, and also the low expression of IKKβ, indicates that NF-κB is not activated by the canonical pathway. Combined with the overexpression of the NIK gene in Her2I, this leads to the hypothesis that in Her2I, NF-κB is being activated by IKBKE and the alternative pathway.In BA, the overexpression of TRAF3 -- an inhibitor of the alternative pathway, suggests that the activation of NF-κB may also occur via the canonical pathway.In summary, we hypothesize that the activation of NF-κB in Her2I tumors is initiated by the IKBKE oncogene and the alternative pathway, while the activation of NF-κB in BA tumors is initiated by IKBKE and the canonical pathway. Boehm et al (Cell, 2007) shown that NF-κB can be inhibited by simultaneously targeting AKT and IKBKE. Combined with our findings, this raises the interesting possibility of developing a targeted therapy for the BA and Her2I breast tumors. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1164.

Final Result of Non-Anthracycline Containing Weekly Paclitaxel Plus Carboplatin Regimen as Neoadjuvant Chemotherapy for Breast Cancer.

Abstract Background: Neoadjuvant chemotherapy (NCT) has become an important part in the comprehensive treatment of breast cancer, patients classified with pathological complete remission (pCR) after NCT have superior outcome. A single center, prospective phase II study was initiated to evaluate the activity and safety of non-anthracycline-containing weekly PCb regimen in NCT for breast cancer, which may help our further clinical usage and research.Materials and Methods: Eligible patients with clinical stage IIA∼IIIC breast cancer were assigned to receive four cycles of PCb with the dose of P (Paclitaxel) 80mg/m2 and Cb (Carboplatin) AUC=2, given day 1, day 8 and day 15, out of every 4 weeks. Clinical response and extent of residual disease in breast and axillary lymph nodes (ALN) in surgical removed sample were assessed after completion of NCT. pCR was defined as no invasive cancer in breast and axillary. Estrogen(ER), Progesterone (PR) receptor and HER2 status were detected before treatment by immunohistochemistry, HR (hormonal receptor) was defined positive as either or both ER/PR positive.Results: From Dec. 2007 to Dec. 2008, 107 breast cancer patients received weekly PCb NCT and one with bilateral breast cancer. 85.2% patients were initially diagnosed with stage III diseases, 83 patients had positive ALN confirmed by fine needle aspiration before NCT. 94.4% (102) patients have completed all of 4 cycles weekly PCb treatment. Clinical response rate was 86.1% with clinical complete remission rate 32.4%. 21 patients achieved pCR, with pCR rate 19.4%. 30 cases who had positive ALN before NCT showed negative result in the surgery specimen with ALN downstage rate 36.6%. The incidence of grade 3-4 neutropenia was 40.2% and only 1 patient was reported with febrile neutropenia. Severe thrombocytopenia and anemia occurred in 0.9% and 4.7% of patients, respectively. Peripheral neuropathy was frequent, but never severe, only 5 (4.7%) patients recorded had more than grade 1 toxicity. Patients with ER- disease had superior pCR rate than ER+ patients (32.6% vs. 9.7%, P=0.005). Patients with PR- disease had higher pCR rate than PR+ patients (30.6% vs. 10.2%, P=0.010). pCR rate was 33.3% (8/24) and 15.5% (13/84) in HER2+ and HER2- patients. Furthermore, We used ER, PR and HER2 status to construct molecular classification of breast cancer, patients classified with Luminal A (HR+/HER2-) subtype had the lowest pCR rate, which was 8.3% less than 22.2% in Luminal B (HR+/HER2+), 33.3% in triple-negative (HR-/HER2-) and 40.0% in HER2 positive (HR-/HER2+) subtype patients, P=0.017.Conclusions: Weekly PCb regimen was very active and tolerable as NCT for breast cancer. ER-, PR-, HER2+ and triple negative breast cancer were more likely to achieve pCR. This weekly PCb regimen should consider as a reasonable non-anthracycline-containing option in NCT setting of breast cancer. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1099.

Molekulare Pathologie beim Mammakarzinom

Die Analyse der Genexpressionsmuster beim Mammakarzinom hat eine Klassifikation dieser Tumoren in funf verschiedene molekulare Subtypen (luminal A und B, HER2-Uberexpression, basaler Phanotyp und normaler Phanotyp) ermoglicht, die sich durch prognostische und therapeutische Unterschiede auszeichnen. Diese molekulare Klassifikation des Mammakarzinoms kann mit einer begrenzten Zahl immunhistochemischer Marker annaherungsweise reproduziert werden, allerdings gibt es noch keinen Konsens, was die Selektion der Marker und die Schwellenwerte betrifft. Der Einsatz dieser Klassifikation wird in Zukunft helfen, zielgerichtete Therapien mit den tumorbiologisch klar definierten Subgruppen zu korrelieren, und dadurch die Aussagekraft klinischer Studien verbessern. Die verschiedenen molekularen Subtypen gehen aus histologisch unterschiedlichen Vorlauferlasionen und Differenzierungswegen hervor. Zu den Vorlauferlasionen mit geringem Risiko zahlen atypische Zylinderepithelveranderungen, atypische duktale Epithelhyperplasien und lobulare Neoplasien. Diese Lasionen stellen fakultative prakanzerose Lasionen des niedrigmalignen Mammakarzinoms dar.

Molecular classes of breast cancer and their clinical relevance

Hierarchical clustering of gene expression profiles has shown that breast cancers can be separated into subclasses characterized by distinct gene profiles. It has been known for decades that breast cancer may be classified into estrogen receptor-positive versus estrogen receptor-negative tumors and, more recently, it was discovered that breast cancer may be classified into tumors amplified versus not amplified for human epidermal growth factor receptor-2 (HER-2). Now, with the use of gene expression profiling, estrogen receptor-positive tumors can be separated into luminal A class and B class tumors, revealing different prognoses and most likely different endocrine sensitivity. Much effort has been focused on characterizing the “triple-negative” tumors (basal cell-like and normal breast cell-like classes). The finding that these tumors, similar to tumors among BRCA1/BRAC2 mutation carriers, may respond to poly(adenosine diphosphate ribose) polymerase inhibitors has led to a targeted therapy approach and suggests defects in DNA repair are also a characteristic of basal cell-like tumors in patients harboring wild-type BRCA1.

Prognostic and predictive factors and genetic analysis of early breast cancer

The great heterogeneity of breast cancer makes it impossible to firmly predict which patients with early-stage tumours will or will not need systemic treatments according to the conventional prognostic factors currently employed. In fact, a substantial percentage of patients receive medical treatment for a disease that will not relapse, while another proportion of patients regarded as having good prognostic factors according to the classic criteria do not receive treatment and suffer disease relapse. Considering that most oncological treatments have short- and long-term toxic effects, new methods capable of offering a more precise prognosis need to be developed. The individualisation of the diagnosis of patients with breast cancer based on molecular and gene expression studies is bringing about a veritable revolution in our understanding of the biology of the disease. The new molecular classification of breast cancer, based on these profiles, allows us to establish a prognosis according to the genetic characteristics of each tumour. Such individualisation of the diagnosis of patients with breast cancer will lead to the application of more specific treatments, thereby improving patient survival with lesser toxicity and increased economic savings. Of the different genetic analytical tests available, MammaPrint has been shown to be the option offering the most information on the behaviour of early breast cancer; as a result, it is the most useful technique in deciding the need for oncological treatment as a complement to surgery.

New Molecular Classifications of Breast Cancer

Traditionally, pathologic determinations of tumor size, lymph node status, endocrine receptor status, and human epidermal growth factor receptor 2 (HER2) status have driven prognostic predictions and adjuvant therapy recommendations for patients with early stage breast cancer. However, these prognostic and predictive factors are relatively crude measures, resulting in many patients being overtreated or undertreated. As a result of gene expression assays, there is growing recognition that breast cancer is a molecularly heterogeneous disease. Evidence from gene expression microarrays suggests the presence of multiple molecular subtypes of breast cancer. The recent commercial availability of gene expression profiling techniques that predict risk of disease recurrence as well as potential chemotherapy benefit have shown promise in refining clinical decision making. These techniques will be reviewed in this article.

New molecular breast cancer classification with adjuvant therapy in our population

e11624 Background: The molecular classification (Perou) helped to identify new groups of patients with different biological behaviors. A retrospective, descriptive, comparative trial with adjuvant chemotherapy treatment was conducted. Objectives: Analyze the natural history of the subgroups of patients, frequency, site of relapse and Disease-free survival (DFS). Materials and Methods: 200 Medical charts of patients with breast cancer were analyzed from 1997 to 2007, who had received adjuvant treatment without Trastuzumab. The 92, 5 % of Luminal A, 91 % of Luminal B y C, the 75.9 % of Her2 (+) and the 69.2 % of Triple Negative (TN) had received adjuvant therapy with FAC, while 30% of the last two groups were treated with taxanes and anthracyclines. We evaluated the site of the first relapse after adjuvant treatment in relation to the new molecular classification. Log-rank test was used to compare the rates of Disease-free survival (DFS). Results: Frequency: Luminal A (86, 42%) Luminal B y C (65, 33%) Her2 + (33, 17%) TN: (16, 8%) The locoregional relapse in the TN group was 36.4% (P = 0.003), the average of bone relapses were 64.5% on the four groups without statically significance compared to other groups. The CNS had a greater trend in TN groups (16.7%) and Her2+ (13.6%), compared to Luminal Type A-B (0 % y 8.3 %). Disease-free survival (DFS): Luminal A 65.0 ± 5.0 months Luminal B y C 50.3 ± 4.3 months HER2 42.9 ± 5.5 months TN 31.1 ± 7.3 months In the analysis of type A luminal subgroup, a prolonged disease free time was showed when compared with the others subgroups, of major statistical significance Log rank (p = 0.002). Conclusions: Her2 negative and TN tumors have less DFS and a higher locoregional and CNS relapse. No significant financial relationships to disclose.

MicroRNA involvement in the pathogenesis and management of breast cancer

MicroRNAs (miRNAs) are a highly abundant class of endogenous small non-coding RNAs (18–25 nucleotides in length) that regulate gene expression by targeting protein-coding mRNAs post-transcriptionally. miRNAs have been implicated in...