Subgroup Of Breast Carcinomas Research Articles

Prognostic value of androgen receptor expression and molecular alterations in metastatic triple-negative or low hormone receptor breast carcinomas

Metastatic breast carcinomas (BCs) with phenotype of triple-negative (TNBC) or low hormonal receptor levels [estrogen receptor (ER)/progesterone receptor (PR)<10% and HER2-] are mainly treated with cytotoxic chemotherapy. Targeting androgen receptor (AR) pathway may represent a potential new therapeutic strategy in such group of BCs. We evaluated AR expression by immunohistochemistry and genetic alterations by next-generation sequencing. Among 114 metastatic BCs, 37 (32.5%) cases showed AR expression and 77 (67.5%) lacked AR expression. Statistical analysis revealed that AR expression is associated with older age, lobular carcinoma, positive ER and positive PR in primary tumors, and lymph node metastasis. Patients with AR-positive tumors had significantly longer metastatic intervals and overall survivals. In addition, AR-positive tumors had significantly higher rate of PI3CA mutation. Our results demonstrated that AR expression has prognostic value in this subgroup of metastatic BCs and tumors with AR expression had different molecular alterations compared with those without AR expression.

Reconstructing tumor history in breast cancer: signatures of mutational processes and response to neoadjuvant chemotherapy⋆

Different endogenous and exogenous mutational processes act over the evolutionary history of a malignant tumor, driven by abnormal DNA editing, mutagens or age-related DNA alterations, among others, to generate the specific mutational landscape of each individual tumor. The signatures of these mutational processes can be identified in large genomic datasets. We investigated the hypothesis that genomic patterns of mutational signatures are associated with the clinical behavior of breast cancer, in particular chemotherapy response and survival, with a particular focus on therapy-resistant disease. Whole exome sequencing was carried out in 405 pretherapeutic samples from the prospective neoadjuvant multicenter GeparSepto study. We analyzed 11 mutational signatures including biological processes such as APOBEC-mutagenesis, homologous recombination deficiency (HRD), mismatch repair deficiency and also age-related or tobacco-induced alterations. Different subgroups of breast carcinomas were defined mainly by differences in HRD-related and APOBEC-related mutational signatures and significant differences between hormone-receptor (HR)-negative and HR-positive tumors as well as correlations with age, Ki-67 and immunological parameters were observed. We could identify mutational processes that were linked to increased pathological complete response rates to neoadjuvant chemotherapy with high significance. In univariate analyses for HR-positive tumors signatures, S3 (HRD, P < 0.001) and S13 (APOBEC, P= 0.001) as well as exonic mutation rate (P= 0.002) were significantly correlated with increased pathological complete response rates. The signatures S3 (HRD, P= 0.006) and S4 (tobacco, P= 0.011) were prognostic for reduced disease-free survival of patients with chemotherapy-resistant tumors. The results of this investigation suggest that the clinical behavior of a tumor, in particular, response to neoadjuvant chemotherapy and disease-free survival of therapy-resistant tumors, could be predicted by the composition of mutational signatures as an indicator of the individual genomic history of a tumor. After additional validations, mutational signatures might be used to identify tumors with an increased response rate to neoadjuvant chemotherapy and to define therapy-resistant subgroups for future therapeutic interventions.

Breast Cancer Molecular Subtypes Among Moroccan Women

Introduction: Breast cancer remains despite the therapeutic progress, the leading cause of death by cancer among women. It represents a group of very heterogeneous clinical, histopathological and molecular diseases. Molecular heterogeneity has been demonstrated by genomic analysis, even for similar histology cancers. Four subgroups of breast carcinomas are distinguished: Luminal A, Luminal B, HER2 over expression and Basal - like. The Immuno-histo-chemical analysis useip (estrogen receptors) RE, the PR (progesterone receptors), the ((Human Epidermal Growth Factor Receptor-2), the Ki67 (proliferation marker) HER2, CK5/6) has shown a subdivision into subgroups similar to those found by genomic analysis. These subgroups are different from the point of view of clinical course and response to adjuvant treatment. Objectives: The aim of this work is to study the molecular profile of the breast cancers by immunostaining on Moroccan series to a classification with a prognostic value allowing a treatment tailored to each group of patients. Furthermore, the molecular subgroups were correlated to other clinical and histological factors. Material and methods: It is a prospective study of the laboratory of Anatomy and Pathologic cytology of the children's Hospital, the service I of the maternity hospital in Rabat and in cooperation with the United Nations Centre of pathological anatomy. To do this, 88 cases of breast cancer together were diagnosed between January 1, 2010 and December 31, 2014, taking a period of five years. All tissue samples made subject study of Immuno-histo-chemistry with the following markers: RE, PR, HER2 and Ki67. Only negative triple cases (HR and HER2 negative) benefited from an additional marking with CK5/6 and EGFR to set the basal profile. Results: Series of 88 cases of mammary carcinomas observed on operating parts, ranged in age between 28 and 84 years old, with an average of 51 ± 12, 8. Carcinoma infiltrating non-specific (DOCTORS) was the most frequent (87.5%). Ranks histo-prognostic Scarff Bloom and Richardson (SBR) 2 and 3 respectively accounted for 45.5 and 51.1% of cases and only 2, 3% of the DOCTORS were grade 1. The Luminal B (53.4%) was under the most common molecular group, followed by Luminal A (23.9%), HER2 + (15.9%) and triple negative (6.8%). The correlation of molecular type of tumors with different prognostic factors showed only one significant connection with the SBR grade.

13IN - Diagnostic and Therapeutic Implications of Tumour-Infiltrating Lymphocytes in Breast Cancer

ABSTRACT In several types of tumors, approaches to modulate tumor-associated inflammation have resulted in comparably high response rates in first clinical evaluations. These targeted therapies included immune checkpoint inhibitors and have stimulated interest in the interaction between immune cells and tumor cells. Neoadjuvant therapy approaches in breast cancer have been used as a strategy to characterize subgroups of tumors with increased tumor-infiltrating lymphocytes (TILs). It has been shown that increased TILs are linked to an increased response rate to neoadjuvant therapy and improved prognosis after adjuvant therapy, in particular in triple-negative and HER2 positive breast cancer. We have recently described tumor-infiltrating lymphocytes (TILs) as predictors of pathological complete response to neoadjuvant chemotherapy in the GeparTrio, GeparQuinto and GeparSixto breast cancer trials. To further investigate the immunological status in tumor tissue we have evaluated a total of 12 immunologically relevant genes, including T-cell markers, B-cell markers, chemokines and immunoregulatory factors, in 481 pretherapeutic FFPE samples in the European FP7 project Responsify. All immune mRNAs had a strong positive correlation with each other and with stromal TILs. Hierarchical cluster analysis showed three different immune-subtypes of tumors with different expression of immunological genes and different amounts of tumor infiltrating lymphocytes. The results suggest that expression of immune marker mRNAs in breast cancer is predictive for response to neoadjuvant chemotherapy. In GeparSixto, these immunological parameters can be used in addition to TILs to identify patients with increased response rates to carboplatin. The results should be validated in other breast cancer trials evaluating carboplatin therapy. In addition, the studies investigating TILS and immune mRNA markers suggest that a subgroup of breast carcinomas is immunogenic. The presentation will provide an overview on recent results on immune markers for prediction of response to neoadjuvant chemotherapy and prognosis with a focus in standardized histomorphological evaluation of tumor-infiltrating lymphocytes. The project has been funded within the EU-FP7 project RESPONSIFY No 278659. Disclosure: C. Denkert: Sividon Diagnostics: research funding, co-founder and shareholder.

Neoplastic and stromal cells contribute to an extracellular matrix gene expression profile defining a breast cancer subtype likely to progress.

We recently showed that differential expression of extracellular matrix (ECM) genes delineates four subgroups of breast carcinomas (ECM1, -2, -3- and -4) with different clinical outcome. To further investigate the characteristics of ECM signature and its impact on tumor progression, we conducted unsupervised clustering analyses in 6 additional independent datasets of invasive breast tumors from different platforms for a total of 643 samples. Use of four different clustering algorithms identified ECM3 tumors as an independent group in all datasets tested. ECM3 showed a homogeneous gene pattern, consisting of 58 genes encoding 43 structural ECM proteins. From 26 to 41% of the cases were ECM3-enriched, and analysis of datasets relevant to gene expression in neoplastic or corresponding stromal cells showed that both stromal and breast carcinoma cells can coordinately express ECM3 genes. In in vitro experiments, β-estradiol induced ECM3 gene production in ER-positive breast carcinoma cell lines, whereas TGFβ induced upregulation of the genes leading to ECM3 gene classification, especially in ER-negative breast carcinoma cells and in fibroblasts. Multivariate analysis of distant metastasis-free survival in untreated breast tumor patients revealed a significant interaction between ECM3 and histological grade (p = 0.001). Cox models, estimated separately in grade I–II and grade III tumors, indicated a highly significant association between ECM3 and worse survival probability only in grade III tumors (HR = 3.0, 95% CI = 1.3–7.0, p = 0.0098). Gene Set Enrichment analysis of ECM3 compared to non-ECM3 tumors revealed significant enrichment of epithelial-mesenchymal transition (EMT) genes in both grade I–II and grade III subsets of ECM3 tumors. Thus, ECM3 is a robust cluster that identifies breast carcinomas with EMT features but with accelerated metastatic potential only in the undifferentiated (grade III) phenotype. These findings support the key relevance of neoplastic and stroma interaction in breast cancer progression.

Abstract 810: Amplification of 8q21 in breast cancer is independent of MYC and associated with poor patient outcome

Abstract Introduction Copy number gains involving the long arm of chromosome 8 including high-level amplifications at 8q21 and 8q24 have been reported in up to 60% of breast cancers. While the role of the MYC gene is well established, the significance of the 8q21 amplicon is less clear. The aim of our study was to analyze 8q21 amplification in a large set of breast cancers with clinical follow up data. Experimental procedures The breast cancer tissue microarray used for this study contains a total of 2.197 tumors and has been described in detail. A fluorescence in situ hybridization (FISH) probe was generated from genomic clone RZPDB737E022003D (imaGenes GmbH, Germany) that maps to the centre of the 8q21 amplicon as previously described in the SK-BR-3 breast cancer cell line. The probe contains the entire TMEM70 gene (transmembrane protein 70) and locates 4 kb downstream from TCEB1 (transcription elongation factor B, polypeptide 1), amplification of which was recently described in prostate cancer. A commercially available pericentromeric probe for chromosome 8 was used as reference (CEP 8Z2 SpectrumOrange, Vysis Inc.). A tumor was considered amplified if the ratio of 8q21/centromere 8 was ≥2.0. Ratios &amp;gt;1.0 and &amp;lt;2.0 had been considered as gains and a ratio ≤1.0 as normal. Results A total of 1458 (66.4%) of arrayed cancer samples were assessable by FISH. Copy number alterations of the 8q21 locus were found in 157 (10.7%) interpretable breast cancers, including amplification in 50 (3.4%) tumors and gains in 107 (7.3%). Amplification at 8q21 was associated to high tumor grade (p=0.042). There was no association between aberrations of the 8q21 locus and tumor stage, presence of lymph node metastases or estrogen receptor status (p&amp;gt;0.05 each). Data on MYC amplification were available from a previous study. A combined analysis of MYC and 8q21 identified 90 tumors with amplifications of MYC and/or 8q21. Of these, 28 tumors were amplified for 8q21 only and 54 for MYC only. Co-amplification of both genes was found in the remaining eight tumors. 8q21 amplification was strongly linked to adverse prognosis (hazard ratio 2.18, confidence interval 1.36 to 3.46, p=0.001). There was no impact of 8q21 gains on patient survival (p=0.48). However, a multivariate Cox analysis did not reveal an independent prognostic value of 8q21 amplification (p=0.23). Conclusions In summary, amplification of 8q21 occurs in a subgroup of breast carcinomas with poor prognosis. Copy number changes of 8q21 are independent from MYC and represent a separate amplicon in this chromosomal region. TMEM70 and the close TCEB1 gene in the centre of the 8q21 amplicon are the most likely possible candidate driver genes. 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 810.

Expression of HAb18G is associated with tumor progression and prognosis of breast carcinoma

HAb18G is a recently identified hepatoma-associated antigen and its association with tumor growth, invasion, and angiogenesis has been studied in a variety of tumors. However, its role in the tumor progression of breast cancer has not been explored. HAb18G expression was examined by immunohistochemistry in pathological sections of 1,637 breast tissue samples and by in situ hybridization in 41 cases of invasive breast carcinomas (BC). While not detected in any cases of tumor-like conditions or benign tumors of breast, and only rarely in normal tissue (4.4%), HAb18G expression was gradually up-regulated from atypical ductal hyperplasia (27.3%), to ductal carcinoma-in situ (59.8%), and to BC (61.4%) (P<0.01). Its expression in BC was correlated positively with C-erbB-2 expression and histologic grade (P<0.001), and negatively with the expression of estrogen and progesterone receptors (P<0.001). Significant differences of expression were also identified among the subgroups of BC examined: in decreasing order from invasive micropapillary carcinoma, ductal carcinoma, lobular carcinoma, papillary carcinoma, medullary carcinoma, to mucinous adenocarcinoma (P=0.001), corresponding to their known clinical aggressiveness. In an expanded group of 186 BC patients with proper follow up, our previous findings were confirmed: HAb18G expression was significantly associated with local recurrence, distant metastasis and tumor mortality (P<0.01). We also demonstrated that up-regulated tumor expression of HAb18G was a significant predictor of reduced disease progression-free survival rate and a shorter overall survival, independent of systemic therapies. In conclusion, this study suggests that HAb18G expression is associated with BC progression and prognosis. Further evaluation of this new marker in breast cancer is indicated.

The basal subtype of breast carcinomas may represent the group of breast tumors that could benefit from EGFR-targeted therapies

The recent understanding of the molecular basis of breast cancer growth and progression led to the identification of tumor subtypes with potentially different biologic behavior. In addition, targeted therapies are increasingly successful in cancer treatment. We recently reported that most of the ER-negative/PR-negative/HER2-negative patients, a group that presents a therapeutic challenge for the oncologist, express EGFR. We now report that the majority of these patients express cytokeratin CK5/6 and therefore belong to the basal subtype of breast carcinomas. These basal subtype lesions are usually high-grade tumors of ductal histology with a high proliferation rate. We propose that the majority of the "triple negative" patients have basal subtype tumors with high EGFR expression and that these tumors may be the subgroup of breast carcinomas that could potentially benefit the most from novel EGFR-targeted therapeutic strategies.

Hypoxia gene expression signature in predicting outcome in breast cancer patients

9503 Background: Gene expression profiling (GEP) has been used to identify specific subgroups of breast carcinomas (BC) that differ with respect to clinical and pathological features, including outcome. We have previously identified an expression pattern of 70 genes, associated with a high risk of developing distant metastases. Recently, we have identified a gene expression profile associated with hypoxia by exposing epithelial cells to hypoxic conditions in vitro. We hypothesized that genes induced by hypoxia may distinguish different (biological) classes of breast cancer and have therefore studied the hypoxia gene expression signature in a series of breast carcinomas. Methods: In a series of 295 patients with stage I and II breast cancer, we have previously obtained the expression profile of 25000 genes using microarray analysis. Based on the hypoxia gene expression profile, we have identified a subgroup of BC showing a “hypoxia-like profile” and a subgroup that did not; and we have compared distant metastasis free survival (DMFS) and overall survival (OS) between those two groups. Results: The median follow up was 7.8 years. Eighty tumors showed a hypoxia-like profile; and 215 did not. Patients with a hypoxia-like profile had a 42.1% DMFS at 10 years compared to 74.0% for those that were negative for the hypoxia-like profile (log rank: p<<0,00001); these figures were 43.9% and 80.7%, respectively, for OS (p<<0,00001). In multivariate analysis including clinical, genetic and pathological factors (e.g. pTxNx-stage, angio-invasion, ER-status, age, grade, chemotherapy and the 70-genes prognosis profile) the hypoxia-like profile showed independent predictive value for DMFS and OS. By combining both signatures we were able to distinguish 3 groups (Good Profile, Poor Profile-Non-Hypoxic, Poor Profile-Hypoxic). DMFS for these groups was 85.4%, 61.7% and 36.0% and OS was 94,5%, 66.5% and 37.0% at 10 years, overall p<<0.00001 for both analyses. Conclusions: In this consecutively treated series of BC patients, the hypoxia-like profile identifies patients that differ with respect to prognosis, hypoxia-like profile tumors being associated with worse outcome. Combining different GEP may result in improved classification of BC. No significant financial relationships to disclose.

Alterations of p16-pRb Pathway and Chromosome Locus 9p21–22 in Sporadic Invasive Breast Carcinomas

The p16-pRb pathway represents a vital cell-cycle checkpoint. In the present study we investigated the alterations of this G1-phase protein pathway using immunohistochemical and molecular methods in a series of 55 breast carcinomas and correlated the findings with clinicopathological features of the patients. Furthermore, we examined its relationship with the status of the chromosomal region 9p21-22 performing a deletion map analysis because there are indications that, in addition to CDKN2 and MTS2/p15(INK4B) tumor suppressor genes (TSGs), this area harbors other TSG(s). Aberrant expression (Ab) of p16 and pRb was observed in 26 (47%) and 16 (29%) of the carcinomas, respectively. A statistical trend pointing out an inverse relationship between p16 and pRb expression was found (p = 0.079). Analysis of the region that encodes for p16 by deletion mapping, a PCR-based methylation assay and PCR-SSCP, revealed that deletions and transcriptional silencing by methylation might represent the main mechanisms of CDKN2/p16(INK4A) inactivation in breast carcinomas. The results of deletion mapping also suggest that another TSG(s) may reside at the 9p21-22 area particularly at the D9S162 loci and that co-deletion of this putative gene with CDKN2/p16(INK4A) may play a role in breast carcinogenesis. In addition, microsatellite instability (MI), a marker of replication error phenotype (RER+), was observed with a frequency of 16% in the area examined and was inversely related with loss of heterozygosity (LOH). Interestingly, most cases with MI at the region encoding for p16 were aggregated in a subgroup of breast carcinomas with no other obvious genetic and/or epigenetic CDKN2/p16(INK4A) alterations. We speculate that there is an additional mechanism of CDKN2/p16(INK4A) inactivation. The relationship of p16 protein level pRb, status, the p16-pRb combined immunoprofiles, and the microsatellite alterations detected at the 9p21-22 locus with the patients' clinicopathological parameters revealed two significant correlations: one between normal pRb expression and lymph node involvement (p = 0.0263), and the other between microsatellite alterations (LOH and or MI) and tumor size (p = 9.2 x 10(-3)). In view of the heterogenous nature of breast cancer, we suggest that in a significant proportion of breast carcinomas, deregulation of the p16-pRb pathway in association with another, as-yet unidentified, TSG(s) of the 9p21-22 region may play a role in initiating or progressing the oncogenic procedure, while in other subgroups, alternative molecules may play this role.

A subgroup of breast carcinomas is cytogenetically characterized by trisomy 12

Chromosome analysis of short-term cultured breast carcinoma cells revealed trisomy 12 in four cases. In one tumor it was the only abnormality. The second case showed cytogenetic polyclonality, but the mainline had +12 as the sole change. In the remaining two tumors, trisomy 12 was part of more complex karyotypes. These findings, especially when coupled with similar information on previously published cases, show that gain of chromosome 12 is a recurrent and sometimes early event in breast carcinogenesis.