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Children receiving HCT loose protective immunity to vaccines received pre-HCT. Therefore, revaccination post-HCT is of major importance. In Denmark, a vaccination schedule with fewer doses post-HCT has been used, including two doses for diphtheria, tetanus, polio, measles, mumps, and rubella, and one dose only for Haemophilus influenzae type B. The background for this was the presumption that post-HCT immunization constituted booster vaccination of donor immunity. Our objective was to evaluate the proportion of children protected after the scheduled vaccination programme. A nationwide retrospective cohort study of all children who have received an HCT in Denmark during 1994-2012. Antibody levels were analysed in blood samples drawn before and after vaccination, and the probability of achieving protection after the scheduled immunization programme was estimated. A total of 198 children were included. The protection post-immunization was as follows: diphtheria 75.3%, tetanus 89.1%, polio 97.7%, and Haemophilus influenzae type B 94.8%. For diphtheria and tetanus, the probability of achieving protection increased to 93.8% and 97.3%, respectively, after a third dose. For measles, mumps, and rubella, the probability of achieving protection was 89.4%, 80.9%, and 94.2%, respectively. In conclusion, our findings support a more extensive vaccination schedule including three doses for diphtheria and tetanus which are in line with current international guidelines.
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Anticorpos Antivirais/sangue , Transplante de Células-Tronco Hematopoéticas , Esquemas de Imunização , Imunização Secundária/métodos , Vacinas/imunologia , Adolescente , Assistência ao Convalescente/métodos , Assistência ao Convalescente/normas , Biomarcadores/sangue , Criança , Pré-Escolar , Dinamarca , Feminino , Seguimentos , Humanos , Imunização Secundária/normas , Lactente , Recém-Nascido , Modelos Logísticos , Masculino , Guias de Prática Clínica como Assunto , Estudos Retrospectivos , Vacinas/administração & dosagemRESUMO
MicroRNAs (miRNAs) are endogenous non-coding RNAs, which play an essential role in the regulation of gene expression during carcinogenesis. The role of miRNAs in breast cancer has been thoroughly investigated, and although many miRNAs are identified as cancer related, little is known about their involvement in benign tumors. In this study, we investigated miRNA expression profiles in the two most common types of human benign tumors (fibroadenoma/fibroadenomatosis) and in malignant breast tumors and explored their role as oncomirs and tumor suppressor miRNAs. Here, we identified 33 miRNAs with similar deregulated expression in both benign and malignant tumors compared with the expression levels of those in normal tissue, including breast cancer-related miRNAs such as let-7, miR-21 and miR-155. Additionally, messenger RNA (mRNA) expression profiles were obtained for some of the same samples. Using integrated mRNA/miRNA expression analysis, we observed that overexpression of certain miRNAs co-occurred with a significant downregulation of their candidate target mRNAs in both benign and malignant tumors. In support of these findings, in vitro functional screening of the downregulated miRNAs in non-malignant and breast cancer cell lines identified several possible tumor suppressor miRNAs, including miR-193b, miR-193a-3p, miR-126, miR-134, miR-132, miR-486-5p, miR-886-3p, miR-195 and miR-497, showing reduced growth when re-expressed in cancer cells. The finding of deregulated expression of oncomirs and tumor suppressor miRNAs in benign breast tumors is intriguing, indicating that they may play a role in proliferation. A role of cancer-related miRNAs in the early phases of carcinogenesis and malignant transformation can, therefore, not be ruled out.
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Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Feminino , Genes Supressores de Tumor , Humanos , RNA Mensageiro , Valores de ReferênciaRESUMO
Invasive lobular breast cancer (ILC) presents unique challenges and considerations in the realm of surgical management. Characterized by its distinct histological features, including the loss of E-cadherin expression and dys-cohesive growth pattern, ILC often poses diagnostic and therapeutic dilemmas for clinicians. This abstract explores the surgical landscape of ILC, focusing on its epidemiology, clinical presentation, diagnostic modalities, and surgical interventions. Emphasizing the importance of individualized treatment strategies, this narrative delves into the nuances of surgical decision-making, including the role of breast-conserving surgery versus mastectomy, axillary staging, and the significance of margin status. Additionally, advancements in surgical techniques, such as oncoplastic approaches and sentinel lymph node biopsy, are examined in the context of optimizing oncologic outcomes and preserving cosmesis. Through a comprehensive review of current literature and clinical guidelines, this overview aims to provide a nuanced understanding of the surgical considerations inherent to the management of invasive lobular breast cancer.
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INTRODUCTION AND IMPORTANCE: Treatment of simultaneously occurring primary malignancies with separate lymphatic drainage is a surgical and medical challenge. We present a patient in which multidisciplinary management of coexisting melanoma and breast cancer was mandatory for optimal results. CASE PRESENTATION: A 67-year-old female had a primary surgical resection for a skin lesion on the back. Histology revealed melanoma with a Breslow thickness of 4.8 mm. According to guidelines, a wide local excision was scheduled. Prior to the surgery, routine mammography revealed simultaneous ipsilateral breast cancer. A preoperative work-up revealed a pathological lymph node in the left axilla. Biopsies found metastasis from malignant melanoma. She had combined surgery with breast-conserving therapy, wide local excision of the skin on the back, and extended axillary clearance of levels I-III. Final histology revealed axillary metastases both from melanoma and breast cancer. Adjuvant therapy was decided based on a multidisciplinary approach. CLINICAL DISCUSSION: To our knowledge, cases of synchronous primary cutaneous melanoma with biopsy-verified axillary metastases and independent, ipsilateral primary breast carcinoma have not been described. The surgical approach was done according to guidelines. The breast cancer was re-staged based on the histology of the surgical specimen. Adjuvant treatment was a combination of treatment strategies for the two primary malignancies. CONCLUSION: This case highlights the need for a multidisciplinary approach in treating simultaneous breast cancer and melanoma both with axillary metastasis. The optimal treatment approach was based on close collaboration between surgeons, oncologists, radiologists, and pathologists. Multidisciplinary meetings are mandatory for optimal results.
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Benign breast tumors are a nonthreatening condition defined as abnormal cell growth within the breast without the ability to invade nearby tissue. However, benign lesions hold valuable biological information that can lead us toward better understanding of tumor biology. In this study, we have used two pathway analysis algorithms, Pathifier and gene set variation analysis (GSVA), to identify biological differences between normal breast tissue, benign tumors and malignant tumors in our clinical dataset. Our results revealed that one-third of all pathways that were significantly different between benign and malignant tumors were immune-related pathways, and 227 of them were validated by both methods and in the METABRIC dataset. Furthermore, five of these pathways (all including genes involved in cytokine and interferon signaling) were related to overall survival in cancer patients in both datasets. The cellular moieties that contribute to immune differences in malignant and benign tumors were analyzed using the deconvolution tool, CIBERSORT. The results showed that levels of some immune cells were specifically higher in benign than in malignant tumors, and this was especially the case for resting dendritic cells and follicular T-helper cells. Understanding the distinct immune profiles of benign and malignant breast tumors may aid in developing noninvasive diagnostic methods to differentiate between them in the future.
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A case of mass-forming breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) with onset a short time after explanation of the cosmetic prosthesis is reported. The cause of implant removal was carcinoma diagnosed in the ipsilateral breast. The rarity of an almost synchronous manifestation of BIA-ALCL and breast carcinoma and the diagnostic challenges of mass-forming BIA-ALCL in a previously operated breast substantiate this report. The clinical course, diagnostic workup and therapeutic considerations are presented and discussed in detail. This case shows that a diagnosis of BIA-ALCL must always be considered even without a prosthesis in place in patients with a long history of textured implants.
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Implante Mamário , Implantes de Mama , Neoplasias da Mama , Linfoma Anaplásico de Células Grandes , Implante Mamário/efeitos adversos , Implantes de Mama/efeitos adversos , Neoplasias da Mama/patologia , Feminino , Humanos , Linfoma Anaplásico de Células Grandes/diagnóstico , Linfoma Anaplásico de Células Grandes/etiologia , Linfoma Anaplásico de Células Grandes/patologia , Receptores Proteína Tirosina QuinasesRESUMO
Sentinel lymph nodes are the first nodes draining the lymph from a breast and could reveal early changes in the host immune system upon dissemination of breast cancer cells. To investigate this, we performed single-cell immune profiling of lymph nodes with and without metastatic cells. Whereas no significant changes were observed for B-cell and natural killer (NK)-cell subsets, metastatic lymph nodes had a significantly increased frequency of CD8 T cells and a skewing toward an effector/memory phenotype of CD4 and CD8 T cells, suggesting an ongoing immune response. Additionally, metastatic lymph nodes had an increased frequency of TIGIT (T-cell immunoreceptor with Ig and ITIM domains)-positive T cells with suppressed TCR signaling compared with non-metastatic nodes, indicating exhaustion of effector T cells, and an increased frequency of regulatory T cells (Tregs) with an activated phenotype. T-cell alterations correlated with the percentage of metastatic tumor cells, reflecting the presence of metastatic tumor cells driving T effector cells toward exhaustion and promoting immunosuppression by recruitment or increased differentiation toward Tregs. These results show that immune suppression occurs already in early stages of tumor progression.
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Neoplasias da Mama , Neoplasias da Mama/patologia , Linfócitos T CD8-Positivos , Feminino , Humanos , Terapia de Imunossupressão , Linfonodos/patologia , Melanoma , Neoplasias Cutâneas , Subpopulações de Linfócitos T/patologia , Melanoma Maligno CutâneoRESUMO
BACKGROUND: High serum levels of estradiol are associated with increased risk of postmenopausal breast cancer. Little is known about the gene expression in normal breast tissue in relation to levels of circulating serum estradiol. METHODS: We compared whole genome expression data of breast tissue samples with serum hormone levels using data from 79 healthy women and 64 breast cancer patients. Significance analysis of microarrays (SAM) was used to identify differentially expressed genes and multivariate linear regression was used to identify independent associations. RESULTS: Six genes (SCGB3A1, RSPO1, TLN2, SLITRK4, DCLK1, PTGS1) were found differentially expressed according to serum estradiol levels (FDR = 0). Three of these independently predicted estradiol levels in a multivariate model, as SCGB3A1 (HIN1) and TLN2 were up-regulated and PTGS1 (COX1) was down-regulated in breast samples from women with high serum estradiol. Serum estradiol, but none of the differentially expressed genes were significantly associated with mammographic density, another strong breast cancer risk factor. In breast carcinomas, expression of GREB1 and AREG was associated with serum estradiol in all cancers and in the subgroup of estrogen receptor positive cases. CONCLUSIONS: We have identified genes associated with serum estradiol levels in normal breast tissue and in breast carcinomas. SCGB3A1 is a suggested tumor suppressor gene that inhibits cell growth and invasion and is methylated and down-regulated in many epithelial cancers. Our findings indicate this gene as an important inhibitor of breast cell proliferation in healthy women with high estradiol levels. In the breast, this gene is expressed in luminal cells only and is methylated in non-BRCA-related breast cancers. The possibility of a carcinogenic contribution of silencing of this gene for luminal, but not basal-like cancers should be further explored. PTGS1 induces prostaglandin E2 (PGE2) production which in turn stimulates aromatase expression and hence increases the local production of estradiol. This is the first report studying such associations in normal breast tissue in humans.
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Neoplasias da Mama/genética , Mama/metabolismo , Estradiol/sangue , Perfilação da Expressão Gênica , Transcriptoma/genética , Adulto , Idoso , Neoplasias da Mama/sangue , Carcinoma Ductal de Mama/sangue , Carcinoma Ductal de Mama/genética , Carcinoma Intraductal não Infiltrante/sangue , Carcinoma Intraductal não Infiltrante/genética , Ciclo-Oxigenase 1/genética , Citocinas/genética , Quinases Semelhantes a Duplacortina , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Modelos Lineares , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Análise Multivariada , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas Serina-Treonina Quinases/genética , Talina/genética , Trombospondinas/genética , Proteínas Supressoras de Tumor/genéticaRESUMO
BACKGROUND: Polycomb Group (PcG) proteins are epigenetic silencers involved in maintaining cellular identity, and their deregulation can result in cancer. Expression of Mel-18 and Bmi-1 has been studied in tumor tissue, but not in adjacent non-cancerous breast epithelium. Our study compares the expression of the two genes in normal breast epithelium of cancer patients and relates it to the level of expression in the corresponding tumors as well as in breast epithelium of healthy women. METHODS: A total of 79 tumors, of which 71 malignant tumors of the breast, 6 fibroadenomas, and 2 DCIS were studied and compared to the reduction mammoplastic specimens of 11 healthy women. In addition there was available adjacent cancer free tissue for 23 of the malignant tumors. The tissue samples were stored in RNAlater, RNA was isolated to create expression microarray profile. These two genes were then studied more closely first on mRNA transcription level by microarrays (Agilent 44 K) and quantitative RT-PCR (TaqMan) and then on protein expression level using immunohistochemistry. RESULTS: Bmi-1 mRNA is significantly up-regulated in adjacent normal breast tissue in breast cancer patients compared to normal breast tissue from noncancerous patients. Conversely, mRNA transcription level of Mel-18 is lower in normal breast from patients operated for breast cancer compared to breast tissue from mammoplasty. When protein expression of these two genes was evaluated, we observed that most of the epithelial cells were positive for Bmi-1 in both groups of tissue samples, although the expression intensity was stronger in normal tissue from cancer patients compared to mammoplasty tissue samples. Protein expression of Mel-18 showed inversely stronger intensity in tissue samples from mammoplasty compared to normal breast tissue from patients operated for breast cancer. CONCLUSION: Bmi-1 mRNA level is consistently increased and Mel-18 mRNA level is consistently decreased in adjacent normal breast tissue of cancer patients as compared to normal breast tissue in women having had reduction mammoplasties. Bmi-1/Mel-18 ratio can be potentially used as a tool for stratifying women at risk of developing malignancy.
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Biomarcadores Tumorais/análise , Neoplasias da Mama/química , Proteínas Nucleares/análise , Proteínas Proto-Oncogênicas/análise , Proteínas Repressoras/análise , Adulto , Idoso , Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Regulação para Baixo , Feminino , Perfilação da Expressão Gênica/métodos , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Noruega , Proteínas Nucleares/genética , Análise de Sequência com Séries de Oligonucleotídeos , Complexo Repressor Polycomb 1 , Prognóstico , Proteínas Proto-Oncogênicas/genética , RNA Mensageiro/análise , Proteínas Repressoras/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Medição de Risco , Fatores de Risco , Regulação para Cima , Adulto JovemRESUMO
Breast cancer is a heterogenous disease which requires updates on scientific research to offer patients the best possible and personalized treatment. Modern surgical treatment of breast cancer is recently been reviewed and it is clearly a field of continuous change and improvement. The change in treatment strategies is a challenge given that prognosis is already acceptable. The collaboration between specialties across different countries is needed to exchange experience and improve international guidelines. Multidisciplinary teams are mandatory for the patient to be provided with all treatment options and to make an informed decision on their treatment. The major trend in surgical treatment of breast cancer is de-escalating surgery and more focus on tumor biology. A "one-size-fits all" approach does not apply in treatment of breast cancer today. There are two major questions in future aspects of breast cancer treatment; Can surgery in the breast be omitted in patients with a pathological complete response after neoadjuvant therapy? And can some patients be spared axillary surgery? The timing of surgery is also debatable. These are major questions that need to be answered and through randomized controlled trials. This commentary gives an insight on thoughts and scientific research with focus on future aspects of breast cancer treatment.
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Chronic inflammation promotes breast tumor growth and invasion by accelerating angiogenesis and tissue remodeling in the tumor microenvironment. There is a complex relationship between inflammation and estrogen, which drives the growth of 70 percent of breast tumors. While low levels of estrogen exposure stimulate macrophages and other inflammatory cell populations, very high levels are immune suppressive. Breast tumor incidence is increased by obesity and age, which interact to influence inflammatory cell populations in normal breast tissue. To characterize the impact of these factors on tumors and the tumor microenvironment, we measured gene expression in 195 breast adenocarcinomas and matched adjacent normal breast tissue samples collected at Akershus University Hospital (AHUS). Age and Body Mass Index (BMI) were independently associated with inflammation in adjacent normal tissue but not tumors. Estrogen Receptor (ER)-negative tumors had elevated macrophage expression compared with matched normal tissue, but ER-positive tumors showed an unexpected decrease in macrophage expression. We found an inverse relationship between the increase in tumor estrogen pathway expression compared with adjacent normal tissue and tumor macrophage score. We validated this finding in 126 breast tumor-normal pairs from the previously published METABRIC cohort. We developed a novel statistic, the Rewiring Coefficient, to quantify the rewiring of gene co-expression networks at the level of individual genes. Differential correlation analysis demonstrated distinct pathways were rewired during tumorigenesis. Our data support an immune suppressive effect of high doses of estrogen signaling in breast tumor microenvironment, suggesting that this effect contributes to the greater presence of prognostic and therapeutically relevant immune cells in ER-negative tumors.
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Cancer cells can have different patterns of exon usage of individual genes when compared to normal tissue, suggesting that alternative splicing may play a role in shaping the tumor phenotype. The discovery and identification of gene variants has increased dramatically with the introduction of RNA-sequencing technology, which enables whole transcriptome analysis of known, as well as novel isoforms. Here we report alternative splicing and transcriptional events among subtypes of invasive ductal carcinoma in The Cancer Genome Atlas (TCGA) Breast Invasive Carcinoma (BRCA) cohort. Alternative exon usage was widespread, and although common events were shared among three subtypes, ER+ HER2-, ER- HER2-, and HER2+, many events on the exon level were subtype specific. Additional RNA-seq analysis was carried out in an independent cohort of 43 ER+ HER2- and ER- HER2- primary breast tumors, confirming many of the exon events identified in the TCGA cohort. Alternative splicing and transcriptional events detected in five genes, MYO6, EPB41L1, TPD52, IQCG, and ACOX2 were validated by qRT-PCR in a third cohort of 40 ER+ HER2- and ER- HER2- patients, showing that these events were truly subtype specific.
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Processamento Alternativo , Neoplasias da Mama/genética , Carcinoma Ductal de Mama/genética , Perfilação da Expressão Gênica/métodos , Neoplasias da Mama/metabolismo , Carcinoma Ductal de Mama/metabolismo , Estudos de Coortes , Bases de Dados Genéticas , Éxons , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Análise de Sequência de RNA/métodosRESUMO
Breast cancer patients with Luminal A disease generally have a good prognosis, but among this patient group are patients with good prognosis that are currently overtreated with adjuvant chemotherapy, and also patients that have a bad prognosis and should be given more aggressive treatment. There is no available method for subclassification of this patient group. Here we present a DNA methylation signature (SAM40) that segregates Luminal A patients based on prognosis, and identify one good prognosis group and one bad prognosis group. The prognostic impact of SAM40 was validated in four independent patient cohorts. Being able to subdivide the Luminal A patients may give the two-sided benefit of identifying one subgroup that may benefit from a more aggressive treatment than what is given today, and importantly, identifying a subgroup that may benefit from less treatment.
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Biomarcadores Tumorais , Neoplasias da Mama/genética , Neoplasias da Mama/mortalidade , Metilação de DNA , Transcriptoma , Neoplasias da Mama/patologia , Análise por Conglomerados , Epigênese Genética , Epigenômica/métodos , Feminino , Dosagem de Genes , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , PrognósticoRESUMO
Tumor size, as indicated by the T-category, is known as a strong prognostic indicator for breast cancer. It is common practice to distinguish the T1 and T2 groups at a tumor size of 2.0 cm. We investigated the 2.0-cm rule from a new point of view. Here, we try to find the optimal threshold based on the differences between the gene expression profiles of the T1 and T2 groups (as defined by the threshold). We developed a numerical algorithm to measure the overall differential gene expression between patients with smaller tumors and those with larger tumors among multiple expression datasets from different studies. We confirmed the performance of the proposed algorithm by a simulation study and then applied it to three different studies conducted at two Norwegian hospitals. We found that the maximum difference in gene expression is obtained at a threshold of 2.2-2.4 cm, and we confirmed that the optimum threshold was over 2.0 cm, as indicated by a validation study using five publicly available expression datasets. Furthermore, we observed a significant differentiation between the two threshold groups in terms of time to local recurrence for the Norwegian datasets. In addition, we performed an associated network and canonical pathway analyses for the genes differentially expressed between tumors below and above the given thresholds, 2.0 and 2.4 cm, using the Norwegian datasets. The associated network function illustrated a cellular assembly of the genes for the 2.0-cm threshold: an energy production for the 2.4-cm threshold and an enrichment in lipid metabolism based on the genes in the intersection for the 2.0- and 2.4-cm thresholds.
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Breast cancer, the second leading cause of cancer death in women, is a highly heterogeneous disease, characterized by distinct genomic and transcriptomic profiles. Transcriptome analyses prevalently assessed protein-coding genes; however, the majority of the mammalian genome is expressed in numerous non-coding transcripts. Emerging evidence supports that many of these non-coding RNAs are specifically expressed during development, tumorigenesis, and metastasis. The focus of this study was to investigate the expression features and molecular characteristics of long non-coding RNAs (lncRNAs) in breast cancer. We investigated 26 breast tumor and 5 normal tissue samples utilizing a custom expression microarray enclosing probes for mRNAs as well as novel and previously identified lncRNAs. We identified more than 19,000 unique regions significantly differentially expressed between normal versus breast tumor tissue, half of these regions were non-coding without any evidence for functional open reading frames or sequence similarity to known proteins. The identified non-coding regions were primarily located in introns (53%) or in the intergenic space (33%), frequently orientated in antisense-direction of protein-coding genes (14%), and commonly distributed at promoter-, transcription factor binding-, or enhancer-sites. Analyzing the most diverse mRNA breast cancer subtypes Basal-like versus Luminal A and B resulted in 3,025 significantly differentially expressed unique loci, including 682 (23%) for non-coding transcripts. A notable number of differentially expressed protein-coding genes displayed non-synonymous expression changes compared to their nearest differentially expressed lncRNA, including an antisense lncRNA strongly anticorrelated to the mRNA coding for histone deacetylase 3 (HDAC3), which was investigated in more detail. Previously identified chromatin-associated lncRNAs (CARs) were predominantly downregulated in breast tumor samples, including CARs located in the protein-coding genes for CALD1, FTX, and HNRNPH1. In conclusion, a number of differentially expressed lncRNAs have been identified with relation to cancer-related protein-coding genes.
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Neoplasias da Mama/genética , Proteínas de Neoplasias/genética , RNA Longo não Codificante/genética , Estudos de Casos e Controles , Cromatina/metabolismo , Feminino , Humanos , Transcrição GênicaRESUMO
BACKGROUND: Ductal carcinoma in situ (DCIS) of the breast is a precursor of invasive breast carcinoma. DNA methylation alterations are thought to be an early event in progression of cancer, and may prove valuable as a tool in clinical decision making and for understanding neoplastic development. RESULTS: We generate genome-wide DNA methylation profiles of 285 breast tissue samples representing progression of cancer, and validate methylation changes between normal and DCIS in an independent dataset of 15 normal and 40 DCIS samples. We also validate a prognostic signature on 583 breast cancer samples from The Cancer Genome Atlas. Our analysis reveals that DNA methylation profiles of DCIS are radically altered compared to normal breast tissue, involving more than 5,000 genes. Changes between DCIS and invasive breast carcinoma involve around 1,000 genes. In tumors, DNA methylation is associated with gene expression of almost 3,000 genes, including both negative and positive correlations. A prognostic signature based on methylation level of 18 CpGs is associated with survival of breast cancer patients with invasive tumors, as well as with survival of patients with DCIS and mixed lesions of DCIS and invasive breast carcinoma. CONCLUSIONS: This work demonstrates that changes in the epigenome occur early in the neoplastic progression, provides evidence for the possible utilization of DNA methylation-based markers of progression in the clinic, and highlights the importance of epigenetic changes in carcinogenesis.
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Neoplasias da Mama/genética , Carcinoma Ductal de Mama/genética , Carcinoma Intraductal não Infiltrante/genética , Metilação de DNA , Regulação Neoplásica da Expressão Gênica , Ilhas de CpG , Progressão da Doença , Epigênese Genética , Feminino , Humanos , Prognóstico , Análise de Sobrevida , Transcrição GênicaRESUMO
Breast cancers today are of predominantly T1 (0.1 ≥ 2.0 cm) or T2 (>2 ≤ 5 cm) categories due to early diagnosis. Molecular profiling using microarrays has led to the notion of breast cancer as a heterogeneous disease both clinically and molecularly. Given the prognostic power and clinical use of tumor size, the purpose of this study was to search for molecular signatures characterizing clinical T1 and T2. In total 46 samples were included in the discovery dataset. After adjusting for hormone receptor status, lymph node status, grade, and tumor subclass 441 genes were differently expressed between T1 and T2 tumors. Focal adhesion and extracellular matrix receptor interaction were upregulated in the smaller tumors while p38MAPK signaling and immune-related pathways were more dominant in the larger tumors. The T-size signature was then tested on a validation set of 947 breast tumor samples. Using the T-size expression signatures instead of tumor size leads to a significant difference in risk for distant metastases (P < 0.001). If further confirmed, this molecular signature can be used to select patients with tumor category T1 who may need more aggressive treatment and patients with tumor category T2 who may have less benefit from it.
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Gene expression studies on breast cancer have generally been performed on tissue obtained at the time of surgery. In this study, we have compared the gene expression profiles in preoperative tissue (core needle biopsies) while tumor is still in its normal milieu to postoperative tissue from the same tumor obtained during surgery. Thirteen patients were included of which eleven had undergone sentinel node diagnosis procedure before operation. Microarray gene expression analysis was performed using total RNA from all the samples. Paired significance analysis of microarrays revealed 228 differently expressed genes, including several early response stress-related genes such as members of the fos and jun families as well as genes of which the expression has previously been associated with cancer. The expression profiles found in the analyses of breast cancer tissue must be evaluated with caution. Different profiles may simply be the result of differences in the surgical trauma and timing of when samples are taken and not necessarily associated with tumor biology.
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BACKGROUND: Increased understanding of the variability in normal breast biology will enable us to identify mechanisms of breast cancer initiation and the origin of different subtypes, and to better predict breast cancer risk. METHODS: Gene expression patterns in breast biopsies from 79 healthy women referred to breast diagnostic centers in Norway were explored by unsupervised hierarchical clustering and supervised analyses, such as gene set enrichment analysis and gene ontology analysis and comparison with previously published genelists and independent datasets. RESULTS: Unsupervised hierarchical clustering identified two separate clusters of normal breast tissue based on gene-expression profiling, regardless of clustering algorithm and gene filtering used. Comparison of the expression profile of the two clusters with several published gene lists describing breast cells revealed that the samples in cluster 1 share characteristics with stromal cells and stem cells, and to a certain degree with mesenchymal cells and myoepithelial cells. The samples in cluster 1 also share many features with the newly identified claudin-low breast cancer intrinsic subtype, which also shows characteristics of stromal and stem cells. More women belonging to cluster 1 have a family history of breast cancer and there is a slight overrepresentation of nulliparous women in cluster 1. Similar findings were seen in a separate dataset consisting of histologically normal tissue from both breasts harboring breast cancer and from mammoplasty reductions. CONCLUSION: This is the first study to explore the variability of gene expression patterns in whole biopsies from normal breasts and identified distinct subtypes of normal breast tissue. Further studies are needed to determine the specific cell contribution to the variation in the biology of normal breasts, how the clusters identified relate to breast cancer risk and their possible link to the origin of the different molecular subtypes of breast cancer.