Academic literature on the topic 'Triple negative breast neoplasms/pathology'

Breast cancer is the most common neoplasm diagnosed in women around the world. Checkpoint inhibitors, targeting the programmed death receptor-1 or ligand-1 (PD-1/PD-L1) axis, have dramatically changed the outcome of cancer treatment. These therapies have been recently considered as alternatives for treatment of breast cancers, in particular those with the triple-negative phenotype (TNBC). A further understanding of the regulatory mechanisms of PD-L1 expression is required to increase the benefit of PD-L1/PD-1 checkpoint immunotherapy in breast cancer patients. In this review, we will compile the most recent studies evaluating PD-1/PD-L1 checkpoint inhibitors in breast cancer. We review factors that determine the therapeutic success of PD-1/PD-L1 immunotherapies in this pathology. In particular, we focus on pathways that interconnect the epithelial-mesenchymal transition (EMT) with regulation of PD-L1 expression. We also discuss the relationship between cellular metabolic pathways and PD-L1 expression that are involved in the promotion of resistance in TNBC.

Breast cancer is the most common neoplasm diagnosed in women around the world. Checkpoint inhibitors, targeting the programmed death receptor-1 or ligand-1 (PD-1/PD-L1) axis, have dramatically changed the outcome of cancer treatment. These therapies have been recently considered as alternatives for treatment of breast cancers, in particular those with the triple-negative phenotype (TNBC). A further understanding of the regulatory mechanisms of PD-L1 expression is required to increase the benefit of PD-L1/PD-1 checkpoint immunotherapy in breast cancer patients. In this review, we will compile the most recent studies evaluating PD-1/PD-L1 checkpoint inhibitors in breast cancer. We review factors that determine the therapeutic success of PD-1/PD-L1 immunotherapies in this pathology. In particular, we focus on pathways that interconnect the epithelial-mesenchymal transition (EMT) with regulation of PD-L1 expression. We also discuss the relationship between cellular metabolic pathways and PD-L1 expression that are involved in the promotion of resistance in TNBC.

AbstractGestational trophoblastic diseases (GTD) are group of pregnancy-related tumors characterized by abnormal levels of ‘β-hCG’ with higher incidence in South-East Asia, especially India. Our laboratory has reported that wild-type BRCA1 transcriptionally regulates β-hCG in triple negative breast cancers (TNBCs). These factors culminated into analysis of BRCA1 status in GTD, which would emanate into elucidation of BRCA1- β-hCG relationship and unraveling etio-pathology of GTD. BRCA1 level in GTD is down-regulated due to the over-expression of DNMT3b and subsequent promoter hypermethylation, when compared to the normal placentae accompanied with its shift in localization. There is an inverse correlation of serum β-hCG levels with BRCA1 mRNA expression. The effects of methotrexate (MTX), which is the first-line chemotherapeutic used for GTD treatment, when analyzed in comparison with plumbagin (PB) revealed that PB alone is efficient than MTX alone or MTX-PB in combination, in showing selective cytotoxicity against GTD. Interestingly, PB increases BRCA1 levels post-treatment, altering DNMT3b levels and resultant BRCA1 promoter methylation. Also, cohort study analyzed the incidence of GTD at Sree Avittom Thirunal (SAT) Hospital, Thiruvananthapuram, which points out that 11.5% of gestational trophoblastic neoplasia (GTN) cases were referred to Regional Cancer Centre, Thiruvananthapuram, for examination of breast lumps. This has lend clues to supervene the risk of GTD patients towards BRCA1-associated diseases and unveil novel therapeutic for GTD, a plant-derived naphthoquinone, PB, already reported as selectively cytotoxic against BRCA1 defective tumors.

INTRODUÇÃO: Os microRNAs (miRNAs) são uma classe de pequenas moléculas não codificadoras de proteínas que regulam a expressão gênica durante a etapa de tradução. Esta regulação é feita pelo pareamento de bases com o mRNA-alvo (RNA mensageiro), resultando na supressão da tradução ou na clivagem do mRNA. A depender se os miRNAs têm como alvo genes supressores de tumor ou oncogenes, eles podem atuar como supressores tumorais ou oncogenes. A imunoistoquímica triplo negativa, no câncer de mama, é, comumente, utilizada como substituto clínico para identificação dos tumores basaloides, que se caracterizam pela expressão de genes epiteliais basais, sendo associados a menores taxas de sobrevida livre de doença e sobrevida global. O câncer de mama triplo negativo faz com que seja necessária a descoberta de marcadores moleculares que possam servir de alvos terapêuticos ou, pelo menos, que sirvam como marcadores preditivos da resposta aos quimioterápicos. OBJETIVO: avaliar a expressão de microRNAs, por PCR em tempo real, no carcinoma mamário ductal invasivo (CDI) triplo negativo. MÉTODOS: Foram avaliados materiais em parafina de tumor de 31 pacientes com as seguintes características: carcinoma invasivo de mama, receptores de estrogênio e de progesterona negativos e HER 2 negativo, bem como tecido mamário histologicamente normal. Foram utilizados kit para extração de RNA de amostras fixadas e parafinadas - miRNeasy FFPE; kit para síntese de cDNA - miScript II RT; kit miScript SYBR Green PCR e miScript miRNA PCR Arrays para análise de 84 sequências de miRNA de câncer humano. Foram avaliados dados clínicos, como idade, paridade, amamentação, status menopausal; variáveis histológicas, como tamanho do tumor, status linfonodal, invasão linfática; características imunoistoquímicas, como expressão de Ki-67, EFGR e CK 5/6. O seguimento das pacientes buscou verificar a ocorrência e o tempo de aparecimento de recidiva loco regional, metástase à distância e óbito. Para análise estatística foi utilizado o software miScript miRNA PCR Array Data Analysis, que utiliza o método de quantificação relativa DeltaCt. RESULTADOS: A análise comparativa dos 31 casos de CDI triplo negativo com os 18 casos de parênquima mamário normal definiu microRNAs hiperexpressos, sendo eles: miR-96-5p (fold-regulation(FR) = 9,68, p = 0,000008), miR-21-5p (FR = 4,47, p = 0,00), miR-7-5p (FR = 5,8, p = 0,00137) , miR-182-5p (FR= 7,92, p = 0,000001), miR-210-3p (FR = 11,83, p = 0,000048), miR-18a-5p (FR = 9,51, p = 0,000034), miR-155-5p (FR= 4,40 , p = 0,00019) e miR-93-5p (FR= 4,15, p = 0,000023). Aponta, ainda, microRNAs com hipoexpressão, a saber: miR-204-5p (FR = -10,26, p = 0), miR-205-5p (FR= -4,07, p = 0,019822), miR-125b-5p (FR= -4,29, p=0) e let 7c-5p (FR= -4,91, p=0). CONCLUSÃO: a expressão de microRNAs no carcinoma ductal invasivo triplo negativo permite diferenciá-lo do tecido normal
INTRODUCTION: MicroRNAs (miRNAs) are a class of small non-coding protein molecules that regulate gene expression during the translation stage. This adjustment is made by base pairing with the mRNA (messenger RNA) target resulting in suppression of translation or cleavage of the mRNA. Depending on whether miRNAs target tumor suppressor genes or oncogenes, they can act as tumor suppressors or oncogenes. The triple negative immunohistochemistry in breast cancer is commonly used as a substitute for clinical identification of basaloid tumors, which are characterized by the expression of basal epithelial genes and are associated with lower rates of disease-free survival and overall survival. The triple negative breast cancer makes necessary the discovery of molecular markers that may serve as therapeutic targets or at least as predictive markers of response to chemotherapy. OBJECTIVE: evaluate the expression of microRNAs by RT-PCR in triple negative breast invasive ductal carcinoma (IDC). METHODS: Paraffin embedded tumor material from 31 patients with the following characteristics were evaluated: invasive breast carcinoma, negative estrogen and progesterone receptor, negative HER 2, and histologically normal breast tissue. Were used: Kit for RNA extraction from fixed and paraffin embedded samples - miRNeasy FFPE; cDNA synthesis kit - miScript II RT; miScript SYBR Green PCR Kit and miScript miRNA PCR Arrays for analysis of 84 miRNA sequences of human cancer. Clinical data such as age, parity, breastfeeding, menopausal status; histological variables such as tumor size, lymph node status, lymphatic invasion; immunohistochemical characteristics, such as expression of Ki-67, EFGR and CK 5/6 were evaluated. The follow-up of patients aimed to verify the occurrence and time of appearance of loco regional recurrence, distant metastasis and death. For statistical analysis the miScript miRNA PCR Array Data Analysis software, which uses the method of relative quantification DeltaCt, was used. RESULTS: A comparative analysis of 31 cases of triple negative IDC with 18 cases of normal breast parenchyma defined microRNAs overexpressed, as follows: miR-96-5p (fold-regulation (FR) = 9.68, p = 0.000008), miR -21-5p (FR = 4.47, p = 0.00), 5p, miR-7 (FR = 5.8, p = 0.00137), miR-182-5p (FR = 7.92, p = 0.000001), miR-210-3p (FR = 11.83, p = 0.000048), miR-18a-5p (FR = 9.51, p = 0.000034), miR-155-5p (FR = 4.40, p = 0.00019) and miR-93-5p (FR = 4.15, p = 0.000023). Furthermore, microRNAs with reduced expression, as follows: miR-204-5p (FR = -10.26, p = 0), miR-205-5p (FR = -4.07, p = 0.019822), miR -125b-5p (FR = -4.29, p = 0) and Let-7c 5p (FR = -4.91, p = 0). CONCLUSION: the expression of microRNAs in triple negative invasive ductal carcinoma allows to differentiate it from normal tissue

Orientador: Sophie Françoise Mauricette Derchain
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
Made available in DSpace on 2018-08-20T06:55:09Z (GMT). No. of bitstreams: 1 Jales_RodrigoMenezes_D.pdf: 3030741 bytes, checksum: 80050dd730b2e28cfc892a361c511985 (MD5) Previous issue date: 2012
Resumo: Objetivo: Avaliar a importância da ultrassonografia na predição de malignidade e sua correlação com os fenótipos Luminal, Her 2 overexpression e Triplo Negativo nos nódulos de mama classificados na categoria BI-RADS 'MARCA REGISTRADA' US 4. Objetivo Artigo 1: avaliar se a medida ultrassonográfica do diâmetro dos cistos pode contribuir com a predição de malignidade em um tipo específico de nódulos complexos classificados na categoria BI-RADS 'MARCA REGISTRADA' -US 4. Objetivo Artigo 2: avaliar as características ultrassonográficas de nódulos mamários classificados na categoria BI-RADS 'MARCA REGISTRADA' -US 4 associadas aos fenótipos Luminal, HER2 overexpression e Triplo Negativo. Sujeitos e métodos: No primeiro artigo foram incluídos em um estudo de corte transversal 48 casos de nódulos com características ultrassonográficas sugestivas de benignidade, entretanto apresentando no seu interior pelo menos um componente cístico. Todos os nódulos foram biopsiados (25 biópsias de fragmento; 23 biópsias de fragmento seguidas de biópsia excisional). O exame anatomopatológico classificou 12/48 (25%) casos como malignos. O maior diâmetro do nódulo, o maior diâmetro do cisto e o padrão de vascularização ao Doppler foram avaliados na predição de malignidade. No segundo artigo, foram selecionados em um estudo de corte transversal 327 nódulos classificados nas categorias BI-RADS 'MARCA REGISTRADA' -US 4a, 4b e 4c. Todos os nódulos foram biopsiados. Os resultados anatomopatológicos foram classificados em benigno 195 (60%) ou maligno 132 (40%). Os nódulos malignos foram então agrupados em três subtipos fenotípicos: Luminal, Her 2 overexpression e Triplo Negativo. As características ultrassonográficas dos nódulos foram comparadas com a categorização fenotípica. Resultados: no primeiro artigo, o padrão da vascularização[presente na lesão (p=1) ou presente imediatamente adjacente à lesão (p=0,46)] não esteve relacionado com a malignidade, enquanto os maiores diâmetros do nódulo e do cisto apresentaram uma relação significativa com a malignidade (p=0,02 e p<0,001, respectivamente). No segundo artigo, as subcategorias BI-RADS 'MARCA REGISTRADA'-US 4a, 4b e 4c não se relacionaram claramente aos fenótipos Luminal, Her2 overexpression ou Triplo Negativo. Entretanto, margens espiculadas, margens indistintas, halo ecogênico e reforço acústico posterior relacionaram-se significativamente com o fenótipo Luminal. Além disso, margens circunscritas e atenuação das ondas de ultrassom relacionaram-se positivamente com o fenótipo Triplo Negativo. Nenhuma característica ecográfica associou-se ao fenótipo Her2 overexpression. Conclusões: O primeiro artigo traz o conceito inédito de que o diâmetro máximo do cisto é um bom preditor de malignidade em nódulos complexos que, exceto pela presença de um ou mais cistos, seriam classificados como provavelmente benignos (BI-RADS 'MARCA REGISTRADA' -US 3). O segundo artigo está em concordância com o conhecimento atual de que existe associação entre variáveis ultrassonográficas como margens, halo ecogênico e características acústicas posteriores e os subtipos fenotípicos Luminal e Triplo Negativo. Entretanto, na amostra avaliada, essa associação não se manifestou claramente na subcategorização BI-RADS 'MARCA REGISTRADA' -US 4a, 4b e 4c
Abstract: Objective: To evaluate the importance of ultrasound in predicting malignancy and its correlation with the phenotypes Luminal, Her 2 overexpression and Triple Negative in breast masses classified as BI-RADS 'TRADE MARK' -US 4. Article 1: To assess whether cyst diameter might contribute to the prediction of malignancy in complex breast masses. Article 2: To assess the sonographic characteristics of BI-RADS 'TRADEMARK'-US 4 breast masses in the Luminal, Triple Negative and HER2 phenotypes. Methods: In the first article, in a cross-sectional study, we identified 48 breast masses that had sonographic features suggestive of benignity, but presenting at least one cystic component. All breast masses were biopsied (25 core-needle; 23 core-needle and excision). Subsequent histologic analysis was performed and 12/48 (25%) malignancies were identified. Different sonographic measurements (largest diameter of the mass and cyst, vascular pattern) were assessed for the detection of malignancy. In the second article, in a cross-sectional study, we selected 327 masses classified in subcategories BI-RADS 'TRADEMARK' -US 4a, 4b and 4c. All masses were biopsied. The pathologic results were classified as benign 195 (60%) or malignant 132 (40%). The malignant masses were further grouped into three phenotypic subtypes: Luminal, Her 2 overexpression and Triple Negative. We then compared the sonographic features of the malignant lesions according to the phenotypic status of the masses. Results: In the first article, among sonographic features, vascular pattern [(present in the lesion (p=1.0) or present immediately adjacent to the lesion (p=0.46)] was not associated with malignancy, whereas the largest mass and cyst dimension had a significantly positive correlation (p=0.02 and p<0.001, respectively) with tumor malignancy. In the second article, the subcategories BI-RADS 'TRADEMARK' -US 4a, 4b and 4c were not clearly related to the phenotypes Luminal, Her2 overexpression or Triple Negative. However, spiculated margins, indistinct margins, echogenic halo, and posterior acoustic shadowing were significantly correlated with the Luminal phenotype. Moreover, circumscribed margins and attenuation were positively related to the Triple Negative phenotype. No sonographic variable was associated with Her2 overexpression phenotype. Conclusions: The first article presents the new concept that cyst diameter is a good predictor of malignancy in complex breast tumors which, except for the presence of the anechoic formation, would otherwise be rendered as probably benign (BI-RADS 'TRADEMARK' 3). The second article is in agreement with current knowledge that there is an association between ultrasound features as margins, posterior acoustic features and lesion boundary and phenotypic subtypes Luminal and Triple Negative. In our sample, this association was not clearly expressed in the subcategorization BI-RADS 'TRADEMARK' -US 4a, 4b and 4c
Doutorado
Oncologia Ginecológica e Mamária
Doutor em Ciências da Saúde

Triple-negative breast cancer (TNBC) is an aggressive cancer subtype that displays poor prognosis due to a lack of targeted therapies and an early pattern of spread. Recent evidence also points to a correlation between cancer “stem-like” cells (CSCs) and the inherently aggressive traits of TNBC. As such, targeting signalling pathways which support metastasis and CSC populations may represent an important therapeutic strategy to treat these tumours and improve current patient outcomes. The non-receptor tyrosine kinase FAK (focal adhesion kinase) is known to influence cancer development and progression, with its upregulation common in several cancer types. Indeed, FAK can regulate various cellular processes associated with disease progression including, cell survival, migration and stem-like behaviours. Therefore, we explored the influence of FAK in TNBC cells and the potential benefit of its targeting in this subtype. Whilst assessment of FAK expression and activity across a panel of breast cancer cell lines representing the major clinical subtypes revealed that FAK was not significantly augmented in MDA-MB-231 cells (model of TNBC) versus other models, MDA-MB-231 cells displayed a FAK-dependent migratory and invasive behaviour involving FAK-mediated activation of Akt and STAT3. These observations also extended to cell proliferation, with pharmacological or genetic FAK inhibition leading to perturbed cell cycle progression. Whilst FAK did not contribute to the maintenance of a CSC subpopulation, FAK was necessary for their anoikis resistance and mammosphere self-renewal, the latter regulated by FAK-dependent modulation of β-catenin through GSK3β and interaction between the FAK/Wnt signalling pathways. Using computational modelling, several novel FAK inhibitors that targeted FAK kinase-independent scaffolding function were developed and screened to assess in vitro efficacy in TNBC cells. Of all 45 compounds, ‘compound 9’ showed significantly improved ability to reduce cell proliferation and migration versus the lead compound, chloropyramine. As expected, this agent had little effect of FAK phosphorylation but appeared to reduce focal-adhesion targeting and subcellular distribution of FAK and significantly inhibited cell migration and growth. Our in vitro data support a case for FAK as a promising therapeutic target in TNBC with an ability to suppress both tumorigenic events and those associated with metastasis. Targeting FAK scaffolding function may represent a novel approach to developing FAK inhibitors that can circumvent resistance traditionally associated with kinase inhibitors.

Therapeutics targeting the PI3K (phosphatidylinositol 3-kinase) and the Ras/MAPK (mitogen-activated protein kinases) pathways have potential as non-toxic treatments for triple-negative breast cancer due to their frequent over-activation in several forms of cancer. Interestingly, the PI3K and Ras/MAPK pathways have been shown to incite cancer dormancy behavior individually and tumorigenic behavior in unison when induced in healthy breast epithelial cells (MCF-10A) in vivo. Tumorigenesis and metastasis are heavily reliant on the specific mechanical and adhesive properties of cells, including decreased stiffness, increased mechanosensitivity, and decreased adhesion. However, the describe cellular behaviors are poorly understood for dormant cancer phenotypes. Understanding the mechanical and adhesive behaviors of MCF-10A cells as a function of PI3K and/or Ras/MAPK pathway over-activation further explores the cross-talk enabling unique dormant and tumorigenic characteristics. Cellular viscoelasticity and adhesion were measured for MCF-10A cells with PTEN (phosphatase and tensin homolog) knockout and activated KRAS (Kristen rat sarcoma viral oncogene homolog) overexpression to activate the PI3K and Ras/MAPK pathways respectively with atomic force microscopy. PTEN knockout alone has no observable influence on cell adhesion but resulted in softer cells with less organized cytoskeleton. Activated KRAS overexpression increased cell stiffness and cell adhesion regardless of PTEN expression level. Moreover, the overexpression of activated KRAS enhanced the sensitivity of cells to the substrate stiffness. The findings suggest that the cancer-associated pathways PI3K and Ras/MAPK regulate cell adhesion and mechanics to promote tumor formation and metastasis. More importantly, the results that signify mutations of different molecular pathways associated with cancer dormancy regulate cell mechanics differently suggests that cell stiffness is a biomarker that detects and differentiates different types of dormant cancers.

Tumor heterogeneity observed between patients has made it challenging to develop universal or broadly effective cancer therapies. Therefore, an ever-growing movement within cancer research aims to tailor cancer therapies to individual patients or specific tumor subtypes. Tumor stratification is generally dictated by the genomic mutation status of the tumor cells themselves. Importantly, non-genetic influences – such as interactions between tumor cells and other components of the tumor microenvironment – have largely been ignored. Therefore, in an effort to increase treatment predictability and efficacy, we investigated how tumor-stroma interactions contribute to drug sensitivity and drug resistance. I designed a high throughput co-culture screening platform to measure how tumor-stroma interactions alter drug mediated cell death. I identified tumor-stroma interactions that strongly desensitize or sensitize cancer cells to various drug treatments. The directionality of these observed phenotypes was dependent on the stromal cell tissue of origin. Further study revealed that interactions between tumor cells and fibroblasts modulate apoptotic priming in tumor cells to mediate sensitivity to chemotherapeutics. The principles uncovered in this study have important implications on the use of drugs that are designed to enhance apoptosis. For example, based on our screening data, I hypothesized and experimentally validated that the effectiveness of BH3 mimetic compounds would be strongly dependent on the fibroblast growth environment. Taken together, our study highlights the importance of understanding how environmental interactions alter the drug responses of cancer cells and reveals a mechanism by which stromal cells drive broad spectrum changes in tumor cell sensitivities to common chemotherapeutics.

INTRODUÇÃO: Carcinomas mamários triplo-negativos correspondem ao grupo heterogêneo de neoplasias mamárias caracterizadas pela ausência de expressão dos receptores de estrogênio e progesterona e sem amplificação ou superexpressão do HER2. São mais prevalentes em mulheres jovens e em afrodescendentes. Eles se associam frequentemente ao fenótipo basal-símile determinado geneticamente, entretanto, incluem também outros tipos moleculares intrínsecos. Metodologias de análise genética de novas gerações têm permitido sua estratificação em subgrupos distintos, o que justifica a heterogeneidade clínica deste grupo de neoplasias. A identificação desses subgrupos através de marcadores imunoistoquímicos de aplicação prática ainda é pouco explorada, embora seja uma ferramenta promissora na sua estratificação e determinação de alvos terapêuticos. OBJETIVOS: Nosso objetivo é explorar os perfis imunoistoquímicos dos carcinomas mamários triplo-negativos em mulheres com idade até 45 anos e investigar possíveis diferenças entre as cinco regiões geográficas brasileiras. MÉTODOS: Selecionamos 118 amostras de tumores de pacientes com idade até 45 anos, com carcinoma invasivo, blocos de parafina disponíveis e perfil imunoistoquímico triplo-negativo, procedentes das cinco regiões geográficas. Estes casos foram revisados quanto à determinação de tipo e grau histológico e as seguintes características anatomopatológicas: contorno do tumor, presença e fração do componente \"in situ\", embolização vascular peritumoral, tipo e grau da reação estromal, presença de necrose tumoral e formação de túbulos pela neoplasia. Foram selecionadas áreas representativas do tumor para construção de blocos de microarranjos de tecido para estudo imunoistoquímico. Foram pesquisados os seguintes marcadores: citoqueratinas basais 5/6 e 14, citoqueratinas luminais 8 e 18, receptor do fator de crescimento epidérmico (EGFR ou HER1), receptor de androgênio, e-caderina, catenina-beta, claudinas 3, 4 e 7, vimentina, actina de músculo liso, p63, ALDH1 e Ki-67. De acordo com a expressão dos marcadores, os tumores foram classificados nos subgrupos basal-símile (expressão de citoqueratina basal 5/6 e/ou EGFR-positivo), claudina-baixo (claudinas e e-caderina-negativos), mesenquimal (vimentina-positivo), apócrino (receptor de androgênio-positivo), mioepitelial (p63 ou actina de músculo liso positivos), com perfil de células tronco (ALDH1 positivo), ou indefinido (padrões negativo para todos os marcadores). Nestes subtipos, a atividade proliferativa foi analisada através da expressão de Ki-67. As neoplasias provenientes das cinco regiões geográficas foram comparadas quanto às características histológicas e perfis imunoistoquímicos. RESULTADOS: A idade das pacientes variou de 26 anos a 45 anos ( média 38,3 +/-4,9 e mediana de 39 anos ). O tipo histológico mais frequente foi o carcinoma de tipo histológico não especial (107/118 casos; 90,7%). Observamos maior proporção de carcinomas de alto grau nas regiões nordeste, sul e sudeste. Os marcadores imunoistoquímicos não mostraram diferenças nas frequências entre as diferentes regiões geográficas. Observamos baixa atividade proliferativa determinada pela expressão do Ki-67 nos subgrupos com expressão do receptor de androgênio (apócrino) e sem expressão de vimentina (padrão não mesenquimal). Os tumores da região Nordeste, Sul e Sudeste apresentaram maior atividade proliferativa. Tumores ricos em linfócitos intratumorais apresentaram menor expressão de marcadores basais e do perfil basal-símile. CONCLUSÕES: Os subtipos moleculares determinados através da expressão imunoistoquímica não mostraram diferenças nas frequências entre as diferentes regiões geográficas. Os tumores das regiões Nordeste, Sul e Sudeste apresentaram maior atividade proliferativa. Os carcinomas ricos em linfócitos intratumorais apresentaram frequência menor do perfil basal
BACKGROUND: Triple-negative breast carcinomas (TNBC) correspond to a heterogeneous group of neoplasia characterized by the lack of expression of estrogen and progesterone receptors, and by the absence of amplification or overexpression of HER2. They are more prevalent among African descendants and younger women. They are often associated with the basal-like genetic phenotype; however, other intrinsic molecular types are included. Genomic analyses of next-generation methods have allowed stratification of TN breast carcinomas into distinct subgroups, explaining the clinical heterogeneity of this group of neoplasias. The identification of these subgroups by immunohistochemical markers is not well explored, although it represents a potential useful tool for the stratification and determination of therapeutic targets. OBJECTIVES: Our aim is to explore the TNBC immunohistochemical profile in patients of 45 year-old or younger, and to investigate possible differences among the five Brazilian geographic regions. METHODS: We\'ve selected 118 samples of tumors from patients up to 45 years-old from five Brazilian geographic regions, with invasive carcinoma, available paraffin blocks, and triple-negative immunohistochemical profile. All the cases were reviewed as for determination of histologic type and grading, and the following pathological features: tumor contour, presence and percentage of in situ component, peritumoral vascular embolization, type and grade of stromal reaction, presence of tumoral necrosis, and tubule formation by neoplasia. Representative tumor areas were selected for tissue microarray construction for immunohistochemical study. The following markers were studied: Basal cytokeratins 5/6 and 14; luminal cytokeratins 8 and 18; Epidermal growth factor receptor (EGFR or HER1); androgen receptor; e-cadherin; catenin-beta; claudins (3,4 and 7); vimentin; smooth-muscle actin; p63, ALDH1, and Ki-67. According to the expression of the markers, the tumors were grouped in the basal-like subgroups (basal cytokeratins 5/6 and/or EGFR positive), claudin-low (claudins and/or e-cadherin negative), mesenchymal (vimentin-positive), apocrine (androgen receptor positive), myoepithelial (p63 and/or smooth muscle actin positive), stem-cell (ALDH1-positive), or undefined (negative for all markers). In these subtypes the proliferative activity through the Ki-67 expression was analyzed. Neoplasias from the five regions were compared as for histological characteristics and immunohistochemical profiles. RESULTS: The age of patients ranged from 26 years to 45 years (mean 38.3 +/- 4.9 and median of 39 years). The most common histological type was no special histological type (NST) of carcinoma (107/118 cases, 90.7%). We observed a higher proportion of high-grade carcinomas in the regions Northeast, South and Southeast. Compared to the Midwestern and Northern regions there was no statistically significant difference (p = 0.03). The immunohistochemical markers showed no differences in the frequencies between the different geographical regions. We observed low proliferative activity determined by Ki-67 expression in the subgroups with androgen receptor expression (apocrine) and no expression of vimentin (no mesenchymal pattern). Tumors of the Northeast, South and Southeast have higher proliferative activity. There was a lower frequency of immunohistochemical markers associated with basal molecular type between tumors rich in lymphocytes. CONCLUSIONS: The molecular subtypes determined by immunohistochemical expression have shown no differences in the frequencies among the different geographical regions. Tumors in the Northeast, South and Southeast had higher proliferative activity. Carcinomas rich in intratumoral lymphocytes had lower frequency of basal profile

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Medicine in Diagnostic Radiology Johannesburg, 2019
INTRODUCTION Breast cancer is one of the leading causes of cancer deaths worldwide. Triple negative breast Cancer (TNBC) is an aggressive subtype, commonly described as presenting at a younger age, in women of African descent and in low socioeconomic groups. Commonly it demonstrates benign imaging features making diagnosis a challenge. Early detection and treatment is imperative. AIM To determine the common imaging features of TNBC in South Africa. METHOD A retrospective study was conducted at a tertiary institution in South Africa. the study population included all biopsy proven TNBC patients presenting between 01/01/2012 – 30/06/2016. All the initial mammograms were re-read by three independent radiologists using a data collection sheet. Illegible or incomplete reports were excluded from the study. RESULTS In our population, TNBC commonly presented in African women with an average age of 54.2 and range 25-95 years, with 47% being pre-menopausal. Typical mammographic features were an oval (27%) or irregular (27%) shaped mass with well circumscribed margins (33%). Our lesions were much larger than those reported in the literature (1). Global asymmetry and architectural distortion were commonly associated features. On ultrasound, the lesions were mostly irregularly shaped (56%) with spiculated borders (29%) and hypoechoic (80%) with axillary adenopathy (81%). CONCLUSION The majority of our patient population presented with a clinically palpable mass, that was larger and had more aggressive features than usually described in the literature. This can be attributed to delayed presentation, due to numerous factors. In order to improving the detection rate and reduce mortality, education and screening programs play a major role.
E.K. 2019

Chemotherapy remains the only available treatment for triple-negative (TN) breast cancer. Although some TN breast cancers respond initially to neoadjuvant chemotherapy, the majority of patients die within three years of treatment due to recurrent tumor growth. Developing ex vivo models for TN breast cancer recurrence and defining responsible molecules will be crucial to developing effective combination therapies for TN breast cancer patients. We have developed an in vitro model of TN breast cancer dormancy/recurrence. Short-term exposure of tumor cells to chemotherapy at clinically relevant doses enriches for a dormant tumor cell population. Several days after removing chemotherapy, dormant tumor cells regain proliferative ability and establish colonies, resembling tumor recurrence. Tumor cells from "recurrent" colonies exhibit increased chemotherapy resistance, resembling therapy resistance of recurrent tumors in patients. Furthermore, we identify a novel signaling axis [nuclear bFGF/DNA-dependent protein kinase (DNA-PK)] supported by chemotherapy-enriched dormant TN breast cancer cells. This signaling axis drives accelerated DNA repair in chemo-residual TN breast cancer cells. Targeting this axis with either with a bFGF shRNA or DNA-PK small molecule inhibitor blocks recurrent colony formation. Using the Oncomine gene expression database, we found that bFGF expression in tumor samples from TN breast cancer patients predicts five year tumor recurrence following neoadjuvant chemotherapy treatment. Finally, we demonstrate that recurrent tumor cells exhibit increased invasiveness, reflecting the aggressive behavior of recurrent tumors in patients. Collectively, these studies identify a novel signaling axis in TN breast cancer that likely contributes to tumor recurrence and provide molecular targets for developing future therapeutics against TN breast cancer.

Dissertation