Les adénomes hépatocellulaires (AHC) sont des tumeurs bénignes rares qui se développent le plus souvent chez la femme jeune suite à la prise de contraceptifs oraux. Les complications principales sont l’hémorragie et plus rarement, la transformation maligne en carcinome hépatocellulaire (CHC). Des travaux récents ont permis d’identifier 3 groupes moléculaires principales d’AHC qui se définissent par (1) l’inactivation du facteur de transcription HNF1A (H-HCA), (2) l'activation de la voie Wnt/ß-caténine (bHCA) ou (3) la présence d’infiltrats inflammatoires (IHCA).Afin d’identifier les voies de tumorigenèse associées au développement d’AHC inflammatoires (IHCA), une analyse transcriptomique comparant des IHCA à des foies non tumoraux a été réalisée au laboratoire, ce qui a permis d’identifier dans ce groupe tumoral une activation de la voie IL-6/JAK/STAT3. Nous avons recherché de nouvelles altérations géniques et nous avons caractérisé le mécanisme d'activation de la voie IL-6/JAK/STAT dans les IHCA. Les conséquences fonctionnelles sur la voie STAT3 des différents mutants ont été analysées par une modélisation de leur expression dans des lignées hépatocellulaires. Par ailleurs, nous avons réalisé des études génomiques intégrées (analyse CGH-SNP, méthylome et séquençage exome) sur une large série de 250 AHC avec pour objectif d’affiner la classification moléculaire des AHC, d’identifier de nouveaux gènes altérés dans ces tumeurs et d’élucider les mécanismes de transformation maligne des AHC en CHC.Dans le groupe des IHCA, ces analyses nous ont permis d’identifier de nombreux oncogènes activés par mutation somatique ; de plus, trois de ces gènes n’avaient jamais été décrits comme étant mutés dans des tumeurs humaines. Nous avons identifié des mutations activatrices du récepteur à l’IL-6, gp130 dans 60% des IHCA. Nous avons aussi retrouvé des mutations de FRK, une src-like kinase, dans 10% des IHCA, du facteur de transcription STAT3 dans 5% des IHCA, du gène GNAS dans 5% des cas, et de la tyrosine kinase JAK1 dans 1% des cas. Toutes les mutations identifiées étaient somatiques, monoalléliques et mutuellement exclusives. Nous avons pu montrer, dans des systèmes de lignées cellulaires hépatocellulaires, que l'expression des formes mutées de ces gènes est capable d’activer la voie IL-6/STAT3 en absence du ligand IL-6, contrairement aux protéines sauvages. Nous avons identifié des inhibiteurs pharmacologiques qui permettent d’inhiber de façon spécifique ces mutants et qui pourraient être utilisés en clinique pour le traitement des IHCA.Grâce à une technique de CGH-SNP, nous avons identifié des événements récurrents de pertes et gains de chromosomes associés aux groupes moléculaires d’AHC. De façon similaire, l’étude de la méthylation dans les AHC a permis de mettre en évidence un pattern spécifique à chaque sous groupe. Nous avons montré que l’instabilité chromosomique augmente progressivement dans les lésions borderline et dans les CHC développés sur AHC comparés aux AHC classiques. Le séquençage exome de 5 transformations malignes de AHC en CHC a identifié un nombre plus important de mutations dans les AHC qui ont transformé comparé aux AHC classiques ; ce nombre est significativement augmenté dans la partie CHC des tumeurs. La comparaison de la partie bénigne et maligne des tumeurs a mis en évidence l'activation de ß-caténine comme un évènement précoce dans le processus de transformation et a révélé la présence de mutations somatiques fréquentes dans le promoteur de la télomèrase (TERT), identifiées principalement dans la partie maligne des tumeurs.En conclusion, cette étude a permis d’identifier des mécanismes distincts conduisant à l'activation de STAT3 dans les IHCA, renforçant le rôle de la voie JAK-STAT3 dans la tumorigenèse bénigne hépatocellulaire ainsi que le lien entre Src kinases et inflammation. Ces travaux ont permis d’affiner la classification moléculaire des AHC avec des corrélations étroites... / Hepatocellular adenomas (HCA) are rare benign tumors that develop most often in young women after taking oral contraception. The main complications are hemorrhage and rarely, malignant transformation to hepatocellular carcinoma (HCC). Recent work in the laboratory identified three main HCA molecular groups that are defined by (1) inactivation of the transcription factor HNF1A (H-HCA), (2) activation of the Wnt/ß-catenin pathway (bHCA) or (3) the presence of inflammatory infiltrates (IHCA).To identify tumorigenesis pathways associated with the development of inflammatory HCA (IHCA), a transcriptome analysis comparing IHCA to non-tumor liver was performed in the laboratory, leading to the identification of an activation of the IL-6/JAK/STAT3 pathway in these tumors. We sought new gene alterations and we characterized the activation mechanism of the IL-6/JAK/STAT pathway in IHCA. The functional consequences of the different mutants on the STAT3 pathway were analyzed by modeling their expression in hepatocellular cell lines. In addition, we performed integrated genomic studies (CGH-SNP analysis, methylome and exome sequencing) on a wide range of 250 HCA with the aim to refine the molecular classification of HCA, to identify new genes altered in these tumors and to elucidate the mechanisms of malignant transformation of HCA to HCC.In the group of the IHCA, we identified many oncogenes activated by somatic mutation; in addition, three of these genes were never been described as mutated in human tumors. We identified activating mutations in the IL-6 receptor gp130 in 60% of IHCA. We also found mutations in FRK, a src-like kinase, in 10% of IHCA, of the transcription factor STAT3 in 5% of IHCA, of the GNAS gene in 5% of cases, and of the tyrosine kinase JAK1 in 1% of the cases. All identified mutations were somatic and monoallelic and were mutually exclusive. We have shown in hepatocellular cell lines that the expression of mutated forms of these genes is able to activate the IL-6/STAT3 pathway in the absence of the IL-6 ligand, in contrast to wild-type proteins. We have identified pharmacological inhibitors that specifically inhibit the mutants and that could be used for the clinical treatment of IHCA.Using a CGH-SNP technique, we identified recurrent chromosomes gains and losses associated with the HCA molecular groups. Similarly, the study of methylation in HCA highlighted a specific pattern in each subgroup. We showed that chromosomal instability increases gradually in borderline lesions and in HCC developed on HCA compared to classical HCA. Exome sequencing of 5 malignant transformation of HCA to HCC identified a large number of mutations in the transformed HCA compared to classical HCA; and this number is significantly increased in HCC tumors counterpart. Comparison of benign and malignant tumors highlighted the activation of ß-catenin as an early event in the transformation process and revealed frequent somatic mutations in the promoter of the telomerase gene (TERT), identified mainly in the malignant part of tumors.In conclusion, this study has led to the identification of distinct mechanisms leading to the activation of STAT3 in IHCA, strengthening the role of the JAK-STAT3 pathway in benign hepatocellular tumorigenesis and the relationship between Src kinases and inflammation. This work helped to refine the molecular classification of HCA with tight correlations between genotype and phenotype, and led to advances in the identification of major genetic determinants involved in the process of malignant transformation.

Characterization of haptoglobin glycoforms in human serum Petra Darebná (Katedra biochemie, Přírodovědecká fakulta, Univerzita Karlova v Praze, Česká republika) Changes in glycosylation of proteins are associated with several types of cancer, including hepatocelular carcinoma and colorectal carcinoma. This project deals with data independent analysis using ion cyclotron resonance with Fourier transform and tandem mass spectrometry with liquid chromatogramy and multiple reaction monitoring to quantify these changes in hepatocelular cancinoma and colorectal carcinoma with liver metastases. In the first part of the project the haptoglobin was enriched from pooled serum samples of pacients with hepatocellular carcinoma, colorectal cancer and colorectal carcinoma with metastases using hemoglobin immobilized on CNBr-activated Sepharose 4B and then purified by high pressure liquid chromatography. Individual haptoglobin glycopeptides were analyzed using ion cyclotron resonance with Fourier transform. In the second part of the project we analyzed changes in glycosylation depending on diferent tumor diseases in partially depleted serum of individual patients using ethanol precipitation. Individual fucosylated glycoforms of N-glycopeptides of serum proteins were compared with their nonfucosylated forms. In...

Hepatocarcinoma (HCC) é o mais comum tumor maligno primário do fígado. Aurora A é importante durante o ciclo celular, atuando na maturação centrossômica e sua separação, entrada em mitose, montagem de fuso bipolar, alinhamento dos cromossomos na placa metafásica e citocinese. Expressão alterada de Aurora A tem sido associada com o desenvolvimento do tumor e sua superexpressão ocorre em 60% dos HCCs. Inibidores de Aurora quinases têm sido desenvolvidos como drogas antitumorais. 4(4`-Benzamidoanilina)-6,7dimetoxiquizanoline, BADIM, é um recém desenvolvido inibidor da Aurora. Nosso estudo investigou os efeitos de BADIM na linhagem celular HepG2, derivada de HCC, quando tratada com 300, 600 e 1200nm de BADIM por 24 e 48h. Observamos inibição de proliferação, aumento de células tetraplóides, binucleadas e gigantes, bloqueio em G2/M do ciclo celular, alterações nos microtúbulos, mitoses atípicas e apoptose. Por conseguinte, este inibidor é um agente promissor para estudos em HCC, pois atua em pontos críticos relacionados com o processo de tumorigênese. / Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of liver. Aurora A is important during cell cycle, including centrosome maturation and separation, mitotic entry, bipolar-spindle assembly, chromosome alignment on metaphase plate and cytokinesis. Altered expression of Aurora A has been associated with tumor development and its overexpression occurs in 60% of HCC. Aurora kinases inhibitors have been developed as antitumoral drugs. 4(4`-Benzamidoanilino)-6,7-dimethoxiquizanolina, BADIM, is a new Aurora inhibitor. Our study aimed investigates the BADIM effects on HepG2 cell line, derivates of HCC, when treated in 300, 600 and 1200nM for 24 and 48h. We observed inhibition of cell proliferation, increase of tetraploids, binucleated and giant cells, arrest in G2/M cell cycle, microtubules alterations, aberrant cell divisions and apoptosis. Therefore this inhibitor is a promising agent for studies in HCC, since it acts at critical points related to tumorigenesis.

Objective: In this study, the efficiency of telemedical consulting with regard to fine needle aspirates from space-occupying lesions (SOLs) of the liver is investigated for the first time. Study Design: The study includes fine needle aspirations from 62 patients, 33 with hepatocellular carcinoma (HCC) and 29 with non-hepatic tumors. Using the Internetbased iPath system, the initial pathologist submitted 1–8 images from smears and cell block sections. One consultant assessed the cytological and another one the histological images. Both made their diagnoses independent of each other. A final diagnosis was made by immunochemistry of cell block sections. The cytological images were analyzed retrospectively for the occurrence of the most typical HCC indicators. The number of these indicators was related to the initial diagnoses of the three pathologists, and possible reasons for diagnostic errors were analyzed based on this analysis. Results: The accuracy of the preliminary telemedical diagnoses regarding HCC was 82.0% for the cytological images and 87.7% for the histological images. Most of the false diagnoses occurred in tumors with unusual cytological and histological patterns. Conclusions: Telemedical consulting is a valuable tool to obtain a second opinion. However, for improvement of the diagnosis of HCC, supplementary immunochemical tests are necessary.

Objectives: To compare 64-slice contrast-enhanced computed tomography (CT) with 3-Tesla magnetic resonance imaging (MRI) using Gd-EOB-DTPA for the diagnosis of hepatocellular carcinoma (HCC) and evaluate the utility of diffusion-weighted imaging (DWI) in this setting. Methods: 3-phase-liver-CT was performed in fifty patients (42 male, 8 female) with suspected or proven HCC. The patients were subjected to a 3-Tesla-MRI-examination with Gd-EOB-DTPA and diffusion weighted imaging (DWI) at b-values of 0, 50 and 400 s/mm2. The apparent diffusion coefficient (ADC)-value was determined for each lesion detected in DWI. The histopathological report after resection or biopsy of a lesion served as the gold standard, and a surrogate of follow-up or complementary imaging techniques in combination with clinical and paraclinical parameters was used in unresected lesions. Diagnostic accuracy, sensitivity, specificity, and positive and negative predictive values were evaluated for each technique. Results: MRI detected slightly more lesions that were considered suspicious for HCC per patient compared to CT (2.7 versus 2.3, respectively). ADC-measurements in HCC showed notably heterogeneous values with a median of 1.2±0.5×10−3 mm2/s (range from 0.07±0.1 to 3.0±0.1×10−3 mm2/s). MRI showed similar diagnostic accuracy, sensitivity, and positive and negative predictive values compared to CT (AUC 0.837, sensitivity 92%, PPV 80% and NPV 90% for MRI vs. AUC 0.798, sensitivity 85%, PPV 79% and NPV 82% for CT; not significant). Specificity was 75% for both techniques. Conclusions: Our study did not show a statistically significant difference in detection in detection of HCC between MRI and CT. Gd-EOB-DTPA-enhanced MRI tended to detect more lesions per patient compared to contrast-enhanced CT; therefore, we would recommend this modality as the first-choice imaging method for the detection of HCC and therapeutic decisions. However, contrast-enhanced CT was not inferior in our study, so that it can be a useful image modality for follow-up examinations.

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Le carcinome hépatocellulaire (CHC) est la première néoplasie létale du foie, représentant 80 à 90% des cas. Actuellement, la majeure partie des patients bénéficient de solutions thérapeutiques avec des efficacités très modestes. La haute variété étiologique, l’hétérogénéité des tumeurs ainsi que l’absence de médiateurs oncogéniques clés connus dans le développement de cette pathologie sont responsables du manque d’options thérapeutiques. À partir d’un crible génétique du kinome humain, nous avons identifié la tyrosine kinase Yes comme un acteur majeur de la prolifération des cellules de CHC. Yes appartient à la famille des kinases Src qui contrôlent de nombreux processus cellulaires notamment la prolifération, la motilité et la survie. La sur-expression ou activation anormale de Yes est retrouvée dans de nombreux cancers et est souvent associée à un mauvais pronostic. Nous avons démontré par des expériences in vitro et in vivo l’activité pro-proliférative de Yes ainsi que son potentiel oncogénique. Notamment, dans un modèle murin de carcinogenèse hépatique induit par le diéthylnitrosamine, la déplétion génétique de Yes abolit totalement la formation de tumeurs. Grâce aux profils transcriptionnels obtenus dans plusieurs modèles cellulaires de CHC, nous avons découvert que l’activité de Yes est associée à une augmentation des signatures géniques des régulateurs transcriptionnels YAP et TAZ ainsi que du facteur transcriptionnel c-Myc. Ces observations ont abouti à identifier YAP, TAZ et c-Myc comme des nouveaux substrats de la tyrosine kinase Yes. Nous avons montré que la phosphorylation par Yes de YAP et TAZ médie leur recrutement dans le noyau ce qui conduit à une hausse de leur activité transcriptionnelle. Nous avons d’ailleurs confirmé l’importance de YAP et TAZ dans les propriétés prolifératives de Yes, notamment dans différents modèles murins de carcinogenèse hépatique. De manière intéressante, nous avons observé que près de 50% de CHCs humains présentent une activation anormale des kinases Src qui corrèle avec la phosphorylation et activation de YAP. Enfin, nous avons observé in vitro et in vivo que Yes stabilise c-Myc. En effet, l’expression transgénique de Yes constitutivement actif dans des hépatocytes entraine la stabilisation de c-Myc à des stades précoces du développement tumoral et une induction de plusieurs de ses gènes cibles à des stades plus tardifs. En plus de leur synergie d’action, cette étude propose que la tyrosine Yes intervient dans les propriétés oncogéniques de c-Myc. Finalement, nous avons découvert que la kinase Yes joue un rôle dans la progression de la stéatose hépatique. En effet, la progression de la pathologie est abolie à la suite de la déplétion de Yes ou suivant l’inhibition pharmacologique des kinases Src. De plus, la survie des cellules tumorales face à leur élimination par le système immunitaire semble être favorisé par la signalisation Yes qui induit l’expression des points de contrôle immuns PD-L1/2. En conclusion nous avons découvert et caractérisé trois nouveaux effecteurs clés de la signalisation oncogénique de la tyrosine kinase Yes dans le CHC. D’ailleurs, la signature génique induite par Yes permet de prédire la survie des patients atteints de CHC. Ces données fournissent de robustes évidences qui placent la tyrosine kinase Yes comme une cible thérapeutique de choix pour la maladie du CHC. / Hepatocellular carcinoma (HCC) is the first lethal neoplasia of the liver, representing 80 to 90% of cases. Currently, for most patients the therapeutic option only provides modest efficiencies. The high etiological variety and heterogeneity of the tumors as well as the absence of known key oncogenic mediator in the development of this pathology is mainly responsible for the lack of therapeutic option. Based on a genetic screen of the human kinome, we identified the tyrosine kinase Yes as a major player in the proliferation of HCC cells. Yes belongs to the family of Src kinases which control many cellular processes including proliferation, motility and survival. The over-expression or abnormal activation of Yes is detected in many cancers and is often associated with poor prognosis. We have demonstrated in vitro and in vivo the pro-proliferative activity of Yes as well as its oncogenic potential. In particular, in a mouse model of hepatic carcinogenesis induced by diethylnitrosamine, the genetic depletion of Yes completely abolishes the formation of tumors. Thanks to the transcriptional profiles obtained in several cellular models of CHC, we discovered that the activity of Yes is associated with an increase in the gene signatures of the transcriptional regulators YAP and TAZ as well as of the transcriptional factor c-Myc. These observations led to the identification of YAP, TAZ and c-Myc as new substrates for the tyrosine kinase Yes. We have shown that the phosphorylation of YAP and TAZ by Yes mediates their recruitment into the nucleus associated with an increase in their transcriptional activity. We have also confirmed the importance of YAP and TAZ in the proliferative properties of Yes in various mouse models of hepatocarcinogenesis. Interestingly, we observed that nearly 50% of human CHCs exhibit an abnormal activation of Src kinases that correlates with phosphorylation and activation of YAP. Moreover, in vitro and in vivo experiments revealed that Yes stabilizes c-Myc. Indeed, the transgenic expression of constitutively active Yes into hepatocytes leads to the accumulation of c-Myc protein at early stages of tumor development and to the induction of several of its target genes at later stages. In addition to their synergistic action, this study suggests that Yes is involved in the oncogenic properties of c-Myc. Finally, we discovered that Yes kinase plays a role in the progression of fatty liver diseases. Indeed, the progression of the pathology is abolished following the depletion of Yes or the pharmacological inhibition of Src kinases. In addition, the survival of Yes-active tumor cells is associated with the induction of PD-L1/2 immune checkpoints that protect cells from immune elimination. In conclusion, we have discovered and characterized three new key effectors of the oncogenic tyrosine kinase Yes in HCC. Interestingly, the gene signature induced by Yes can predict the survival of patients with HCC. These data provide strong evidence for targeting the tyrosine kinase Yes in HCC.

Hepatocellular carcinoma (HCC) is a common malignancy of the liver that is one of the most frequent causes of cancer-related death in the world. Surgical resection and liver transplantation are the only curative options for HCC, and tumor invasion and metastasis render many patients ineligible for these treatments. Identification of the mechanisms that contribute to invasive and metastatic disease may enlighten therapeutic strategies for those not eligible for surgical treatments. In this dissertation, I describe two sets of experiments to elucidate mechanisms underlying HCC dissemination, involving the activities of Krüppel-like factor 6 and a particular p53 point mutation, R172H. Gene expression profiling of migratory HCC subpopulations demonstrated reduced expression of Krüppel-like factor 6 (KLF6) in invasive HCC cells. Knockdown of KLF6 in HCC cells increased cell transformation and migration. Single-copy deletion of Klf6 in a HCC mouse model results in increased tumor formation, increased metastasis to the lungs, and decreased survival, indicating that KLF6 suppresses both tumor formation and metastasis in HCC. To elucidate the mechanism of KLF6-mediated tumor and metastasis suppression, we performed gene expression profiling and ChIP-sequencing to identify direct transcriptional targets of KLF6 in HCC cells. This analysis revealed novel transcriptional targets of KLF6 in HCC including CDC42EP3 and VAV3, both of which are positive regulators of Rho family GTPases. Concordantly, KLF6 knockdown cells demonstrate increased activity of the Rho family GTPases RAC1 and CDC42, and RAC1 is required for migration induced following KLF6 knockdown. Moreover, VAV3 and CDC42EP3 are also required for enhanced cell migration in HCC cells with KLF6 knockdown. Together, this work describes a novel signaling axis through which KLF6-mediated repression of VAV3 and CDC42EP3 inhibits RAC1Gmediated HCC cell migration in culture, and potentially HCC metastasis in vivo. TP53 gene mutations are commonly found in HCC and are associated with poor prognosis. Prior studies have suggested that p53 mutants can display gain-of- function properties in other tumor types. Therefore, I sought to determine if a particular hotspot p53 mutation, p53R172H, provided enhanced, gain-of-function properties compared to p53 loss in HCC. In vitro, soft agar colony formation and cell migration is reduced upon knockdown of p53R172H, indicating that this mutation is required for transformation-associated phenotypes in these cells. However, p53R172H-expressing mice did not have enhanced tumor formation or metastasis compared to p53-null mice. These data suggest that p53R172H and p53 deletion are functionally equivalent in vivo, and that p53R172H is not a gain-of-function mutant in HCC. Inhibition of the related transcription factors p63 and p73 has been suggested as a potential mechanism by which mutant p53 exerts its gain-of-function effects. Analysis of p63 and p73 target genes demonstrated that they are similarly suppressed in p53-null and p53R172H-expressing HCC cell lines, suggesting a potential explanation for the phenotypes I observed in vivo and in vitro. Together, the studies described in this dissertation increase our understanding of the mechanisms underlying HCC progression and metastasis. Specifically, we find and characterize KLF6 as a novel suppressor of HCC metastasis, and determine the contribution of a common p53 point mutation in HCC. This work contributes to ongoing efforts to improve treatment options for HCC patients.

Indiana University-Purdue University Indianapolis (IUPUI) / MicroRNAs are small RNA molecules that regulate expression of genes involved in development, cell differentiation, proliferation and death. It has been estimated that in eukaryotes, approximately 0.5 to 1% of predicted genes encode a microRNA, which in humans, regulate at least 30% of genes at an average of 200 genes per miRNA. Some microRNAs are tissue-specific, while others are ubiquitously expressed. In liver, a few microRNAs have been identified that regulate specialized functions. The best known is miR-122, the most abundant liver-specific miRNA, which regulates cholesterol biosynthesis and other genes of fatty acid metabolism; it also regulates the cell cycle through inhibition of cyclin G1. To discover other miRNAs with relevant function in liver, we characterized miRNA profiles in normal tissue and identified miR-709. Our data indicates this is a highly abundant hepatic miRNA and is dysregulated in an animal model of type 2 diabetes. To understand its biological role, miR-709 gene targets were identified by analyzing the transcriptome of primary hepatocytes transfected with a miR-709 mimic. The genes identified fell within four main categories: cytoskeleton binding, extracellular matrix attachment, endosomal recycling and fatty acid metabolism. Thus, similar to miR-122, miR-709 downregulates genes from multiple pathways. This would be predicted, given the abundance of the miRNA and the fact that the estimated number of genes targeted by a miRNA is in the hundreds. In the case of miR-709, these suggested a coordinated response during cell proliferation, when cytoskeleton remodeling requires substantial changes in gene expression. Consistently, miR-709 was found significantly upregulated in an animal model of hepatocellular carcinoma. Likewise, in a mouse model of liver regeneration, mature miR-709 was increased. To study the consequences of depleting miR-709 in quiescent and proliferating cells, primary hepatocytes and hepatoma cells were cultured with antagomiRs (anti-miRs). The presence of anti-miR-709 caused cell death in proliferating cells. Quiescent primary hepatocytes responded by upregulating miR-709 and its host gene, Rfx1. These studies show that miR-709 targets genes relevant to cystokeleton structural genes. Thus, miR-709 and Rfx1 may be needed to facilitate cytoskeleton reorganization, a process that occurs after liver injury and repopulation, or during tumorigenesis.

Systematic reviews on diagnostic test accuracy studies provide an overview of the current literature in a systematic and transparent manner. They are the highest level of evidence in clinical research, therefore they are critical to decision-making in the healthcare setting. Cancer is the primary source of mortality in Canada, however early detection of tumors can improve the survival rates and long-term health outcomes of patients. The primary method of cancer diagnosis is histopathological assessment, however, its use remains controversial. It is an invasive procedure and requires resources and clinical expertise not readily available. Noninvasive clinical imaging has been studied as a clinically desirable method for cancer diagnosis, however its diagnostic accuracy has yet to be established in the medical setting. With the increased role of DTA research in medicine, the current literature needs to be summarized in an effective way to properly educate and influence clinical decision-making. The objective of this thesis is to address the current evidence gaps in DTA research by conducting several systematic reviews to evaluate the accuracy of diagnostic methods in cancer-related imaging. The last chapter of the thesis will provide a critical reflection on the current landscape of DTA studies in cancer-related imaging, based on the findings of the reviews in the thesis.