7083 results for "canc*"

in 14.07 milliseconds.

• RNAseq

  RNAseq of pancreatic cancer organoids.

  Study EGAS00001007212

• Integrative_genome_profiling_in_AML

  AML emerges as a consequence of accumulating independent genetic aberrations that direct regulation and/or dysfunction of genes resulting in aberrant activation of signalling pathways, resistance to apoptosis and uncontrolled proliferation. Given the significant heterogeneity of AML genomes, AML patients demonstrate a highly variable response rate and poor median survival in response to current chemotherapy regimens. For the past 4 years we have conducted gene expression profiling on purified bone marrow populations equating to normal haematopoietic stem and progenitor cells from healthy subjects and patients with de novo AML in order to identify AML signatures of aberrantly expressed genes in cancer versus normal. We are now applying a series of bioinformatic methodologies combined with clinical and conventional diagnostic data to establish novel genomics strategies for improved prognostication of AML. Additionally, we use our AML signatures to unravel oncogenic signalling pathway activities in AML patients and test inhibitory drugs for these pathways inn preclinical therapeutic programmes. We consider that superimposing GEP and clinical data for our AML patient cohort with additional data on their mutational status will significantly improve the prognostic power of the study as well as unravel yet unknown mutations associated with aberrant signalling activities of oncogenic pathways.

  Study EGAS00001000858

• Guardians_of_the_genome__protecting_DNA_from_endogenous_sources_of_damage_

  Analysis of mutational signatures caused by DNA repair defects in human induced pluripotent stem (iPS) cells. A reference human iPS cell line will be used for genetic manipulation to introduce homozygous knockouts of 100 genes known to be involved in or connected to DNA repair or DNA editing. Following a defined period of growth after homozygous knockout of each gene, sub clones will be generated and sequenced. The progenitor “parental” IPS cell line will be used to generate reference sequence data, in order to determine the mutational signature acquired due to the gene knockout. This is a pilot study to investigate the effects of oxygen conditions and growth period on mutations acquired

  Study EGAS00001000874

• 65 prostate cancer cases WGS and transcriptome sequencing project

  We obtained whole-genome and transcriptome sequencing of tumor-benign pairs from 65 Asian prostate cancer (PCa) patients. Taken together with the TCGA PCa cohort, our integration analysis provides the first comprehensive mutational landscape of PCas across major ethnics worldwide and reveals potential novel role of frequent altered chromatin remodeler genes in PCas without androgen receptor (AR) alteration and complex rearrangements derived from Chromoplexy. In addition, we identified 5 putative tumor suppressor genes (TSGs) chains including one on chromosome 13q with novel findings of PCDH9 (deletions in 15/65 tumors) which was implicated in aggressive progression of prostate cancer. Finally, the integrative pathway and co-expression network analysis followed by the functional study indicated the frequent altered genes, particularly focal amplifications of PLXNA1 (11/65), in semaphoring signaling of axon guidance pathway may interact with PI3K/AKT and AR signaling and also contribute to the aggressiveness and progression of prostate cancer.

  Study EGAS00001000888

• SeqControl: Process Control for DNA Sequencing

  As next-generation sequencing (NGS) continues to increase in speed and throughput, routine clinical and industrial application draws steadily closer. These “production” uses of NGS will require enhanced quality-monitoring and quality-control to optimize output and reduce costs. We therefore developed a framework called SeqControl for predicting sequencing quality and coverage using a set of 15 metrics describing overall coverage, coverage distribution, base-wise coverage and base-wise quality. Using whole-genome sequences of 27 prostate cancers and 26 normal references we derive multivariate models that predict sequencing quality and depth. SeqControl robustly predicts how much sequencing is required to reach a given coverage depth (AUC = 0.993), accurately classifies clinically relevant formalin-fixed paraffin-embedded samples and makes predictions from as little as 1/8 of a lane of sequencing data (AUC = 0.967). These techniques can be immediately incorporated into existing NGS pipelines to monitor data quality in real-time. SeqControl represents a first step towards statistical process-control for NGS.

  Study EGAS00001000899

• Alveolar Rhabdomyosarcoma case report

  Rhabdomyosarcoma (RMS) is a mesenchymal malignancy phenocopying muscle and is among the leading causes of death from childhood cancer. Metastatic alveolar rhabdomyosarcoma is the most aggressive subtype with an 8% five-year disease-free survival rate when a chromosomal fusion is present, and 40% five-year disease-free survival rate when negative for a fusion event. The underlying biology of PAX-fusion negative alveolar rhabdomyosarcoma remains largely unexplored and is exceedingly rare in Li-Fraumeni syndrome patients. Here, we present the case of an 11-year old male with fusion-negative alveolar rhabdomyosarcoma studied at end of life with a comprehensive functional genomics characterization, resulting in identification of potential therapeutic targets for broader investigation.

  Study EGAS00001004828

• Study on the proliferation history of colorectal adenomas

  Mismatch repair (MMR) deficient colorectal adenomas are composed of transformed cells that descend from a common founder and progressively accumulate genomic alterations but their proliferation history is still largely unknown. Here we rebuilt the proliferation history of four MMR deficient colorectal adenomas from male individuals by deep sequencing the X chromosome and mapping the somatic mutations that were progressively acquired during tumor growth. We developed a novel method to call high and low frequency mutations, to cluster them according to their frequencies and rebuild the proliferation trees directly from these mutation clusters using a recursive algorithm. The trees of all four lesions were formed of a dominant subclone that coexisted with other genetically heterogeneous subpopulations of cells. Despite this similar hierarchical organization, however, the growth dynamics varied among and within tumors, likely depending on a combination of tumor-specific genetic and environmental factors. Our study provides insights into the biological properties of individual MMR deficient colorectal adenomas that may influence their growth and also the response to therapy. Extended to other solid tumors, our approach could inform on the mechanisms of cancer progression, thus providing insight into the best choice of cancer treatment methods.

  Study EGAS00001000883

• A Comparative Analysis of Algorithms for Somatic SNV Detection in Cancer

  Four recently published algorithms for the detection of somatic SNV sites in matched cancer-normal sequencing datasets are VarScan, SomaticSniper, JointSNVMix and Strelka. In this analysis, we apply these four SNV calling algorithms to cancer- normal Illumina exome sequencing of a chronic myeloid leukaemia (CML) patient. The candidate SNV sites returned by each algorithm are filtered to remove likely false positives, then characterised and compared to investigate the strengths and weaknesses of each SNV calling algorithm.

  Study EGAS00001000927

• Von Hippel-Lindau syndrome multi-region exome sequencing project from two patients undertaken at Cancer Research UK's London Research Institute

  Multi-region whole exome sequencing of tumours from patients with Von Hippel-Lindau syndrome reveals convergence of mutayional events upon the PI3L-AKT-mTOR signalling pathway.

  Study EGAS00001000907

• Plasma DNA aberrations in systemic lupus erythematosus revealed by genomic and methylomic sequencing

  We performed a high-resolution analysis of the biological characteristics of plasma DNA in systemic lupus erythematosus (SLE) patients using massively parallel genomic and methylomic sequencing. A number of plasma DNA abnormalities were found. First, aberrations in measured genomic representations (MGRs) were identified in the plasma DNA of SLE patients. The extent of the aberrations in MGRs correlated with anti-double–stranded DNA (anti-dsDNA) antibody level. Second, the plasma DNA of active SLE patients exhibited skewed molecular size-distribution profiles with a significantly increased proportion of short DNA fragments. The extent of plasma DNA shortening in SLE patients correlated with the SLE disease activity index (SLEDAI) and anti-dsDNA antibody level. Third, the plasma DNA of active SLE patients showed decreased methylation densities. The extent of hypomethylation correlated with SLEDAI and anti-dsDNA antibody level. To explore the impact of anti-dsDNA antibody on plasma DNA in SLE, a column-based protein G capture approach was used to fractionate the IgG-bound and non–IgG-bound DNA in plasma. Compared with healthy individuals, SLE patients had higher concentrations of IgG-bound DNA in plasma. More IgG binding occurs at genomic locations showing increased MGRs. Furthermore, the IgG-bound plasma DNA was shorter in size and more hypomethylated than the non–IgG-bound plasma DNA. These observations have enhanced our understanding of the spectrum of plasma DNA aberrations in SLE and may provide new molecular markers for SLE. Our results also suggest that caution should be exercised when interpreting plasma DNA-based noninvasive prenatal testing and cancer testing conducted for SLE patients.

  Study EGAS00001000962

• Immune trajectory of response and adverse effect in immunotherapy-treated hepatocellular carcinoma

  Whilst anti-PD1 immune checkpoint blockade (ICB) has revolutionised treatment for many cancers, its response rates in hepatocellular carcinoma (HCC) remain modest, coupled with common incidences of immune-related adverse events (irAEs). To identify biomarkers and decipher the mechanisms for response and irAEs, we performed multi-dimensional immunoprofiling on peripheral blood and tissue collected before and during anti-PD1 ICB treatment from HCC patients. Single-cell analyses enabled us to identify peripheral biomarkers, in particular, CD11c+ antigen-presenting cells with varying degrees of HLA-DR expression and CD8 effector memory (EM) T cells with CXCR3 tissue-homing capability that are associated with both response and irAEs. We also dissected the mechanisms behind how these immune subsets interface between response and toxicity, showing their intersecting yet diverging trajectories leading to these distinct clinical fates. This study offers new insights on the mechanisms and potentially novel strategies to enhance response and ameliorate irAEs in cancer immunotherapy.

  Study EGAS00001004843

• Comprehensive genomic profiles of small cell lung cancer

  We have sequenced the genomes of 110 small cell lung cancers (SCLC), one of the deadliest human cancers. We found bi-allelic inactivation of TP53 and RB1 in nearly all the tumors analyzed, sometimes by complex genomic rearrangements. Two tumors with wild-type RB1 had evidence of chromothripsis leading to overexpression of Cyclin D1, revealing an alternative mechanism of Rb1 deregulation. Thus, loss of the tumor suppressors TP53 and RB1 is obligatory in SCLC. We further discovered somatic genomic rearrangements of TP73 that create an oncogenic version of this gene, TP73Δex2/3. In few cases, SCLC tumors exhibited kinase gene mutations, providing a possible therapeutic opportunity for individual patients. Finally, we observed inactivating mutations in NOTCH family genes in 25% of human SCLC. Accordingly, activation of Notch signaling in a pre-clinical SCLC mouse model dramatically reduced the number of tumors and extended the survival of the mutant mice. Furthermore, neuroendocrine gene expression was abrogated by Notch activity in SCLC cells. This first comprehensive study of somatic genome alterations in SCLC uncovers several key biological processes and identifies candidate therapeutic targets in this highly lethal form of cancer.

  Study EGAS00001000925

• Circulating Tumor DNA in Checkpoint Inhibitor treated Lung Cancer

  BackgroundImmune checkpoint inhibitors (ICI) are increasingly used to treat non-small cell lung cancer (NSCLC) and there is a critical need for novel predictive/prognostic biomarkers. We evaluated whether dynamics of circulating tumor (ctDNA) can identify NSCLC patients who benefit from single agent ICI.MethodsCirculating cell-free DNA (cfDNA) from 177 patients was analyzed prior ICI and at first treatment evaluation using a Commercial 77-gene panel. We performed de novo mutation calling and corrected for variants related clonal hematopoiesis. ctDNA changes were evaluated as predictors of tumor response estimated with PET/diagnostic CT and survival.ResultsMutations were detected in 159 of 174 (91.4%) analyzable patients. Most responders presented decreasing ctDNA levels, while non-responders had mixed molecular responses. Patients with a >50% molecular ctDNA decrease or no detectable ctDNA demonstrated improved PFS (5.9 versus 1.8 months; HR 0.49, 95%CI, 0.35-0.67, P < .001), and OS (18.9 versus 9.9 months; HR 0.41, 95%CI, 0.30-0.57, P < .001) compared to patients not achieving these endpoints. Clearance of mutations (and no detected ctDNA) had a similar effect (PFS HR 0.45, 95%CI, 0.32-0.61, P < .001; OS 0.37,95%CI, 0.27-0.52, P < .001) compared to patients having stable or additional mutations. After adjusting for clinical factors both >50% ctDNA decrease (HR 0.4, 95% CI, 0.3-0.6, P < .001) and clearance of mutations (HR 0.42, 95% CI, 0.3-0.6, P < .001) remained independent predictors for PFS and OS.ConclusionsctDNA testing reveals significant prognostic albeit not predictive information in ICI treated advanced NSCLC. This relevant information can be obtained with a commercial easy-to-implement ctDNA test that will facilitate extensive testing.

  Study EGAS00001004847

• Therapeutic Resistance to PI3K-alpha Inhibitors

  We have studied the tumor genomic evolution in a patient with metastatic breast cancer bearing an activating PIK3CA mutation. The patient was treated with the PI3Kα inhibitor BYL719 and achieved a lasting clinical response on BYL719, but eventually progressed to treatment and died shortly thereafter. A rapid autopsy was performed and a total of 14 metastatic lesions were collected for further analysis. In order to identify possible genetic determinants of acquired resistance to PI3Kα inhibition, we took a three-step approach. First, we examined both the primary tumor (before BYL719 treatment) and the new lung metastasis by whole genome sequencing (DNA from the spleen was used as a normal control). Then, we analyzed the primary tumor, lung metastasis, and the peri-aortic lesion that remained stable (responding) at the time of progression to BYL719 therapy by whole exome sequencing. Finally, to confirm and expand our findings, we sequenced the primary tumor and all the metastatic lesions to >500-fold coverage using a custom targeted deep-sequencing assay, MSK-IMPACT. Using this 3-step approach, we have demonstrated that patient’s lesion underwent parallel genetic evolution at multiple metastatic sites with different PTEN genomic alterations leading to a convergent PTEN- null phenotype resistant to PI3Kα inhibition. In order to expand our observations, we analyzed paired samples (pre-treatment and at progression) from six additional patients enrolled in the BYL719 trial. Acquired bi-allelic loss of PTEN was found in one additional patient treated with BYL719 whereas in two patients PIK3CA mutations present in the primary tumor were no longer detected at the time of progression. To functionally characterize our findings, inducible PTEN knockdown in sensitive cells resulted in resistance to BYL719, while simultaneous PI3K-p110β blockade reverted this resistance phenotype, both in cell lines and in PTEN-null xenografts derived from our patient. We conclude that parallel genetic evolution of separate sites with different PTEN genomic alterations leads to a convergent PTEN-null phenotype resistant to PI3Kα inhibition.

  Study EGAS00001000991

• Analysis_of_genomic_integrity_of_disease_corrected_human_induced_pluripotent_stem_cells_by_exome_sequencing

  Induced pluripotent stem (iPS) cells hold great promise for autologous cell transplantation. In order to apply this therapy to monogenic disorder, disease-causing mutations must be corrected prior to transplantation. We generated iPS cells from patients with alpha-1 antitrypsin deficiency, which is caused by homozygous non-synonymous mutation in the SERPINA1 gene. In vitro differentiation of patient-derived iPS cells to hepatocytes showed recapitulation of the disease phenotype. We corrected the mutations by gene targeting using zinc finger nuclease (ZFN) and piggyBac transposon technologies. Our mutation correction is highly accurate. There is no exogenous sequence left behind at the targeted site. The corrected iPS cell-derived hepatocytes were indistinguishable from healthy hepatocyte, suggesting that the corrected gene was fully functional. The genomic integrity was also analyzed by CGH and SNP array, showing no genomic alterations. These are important points to ensure clinical safety as well as functional restoration of the corrected gene. One remaining question is if these corrected iPS cells are clinically safe at the single base-pair level. Recent publications suggested that cancer-related mutations are significantly accumulated during iPS cell propagation. We aim to assess the clinical safety of the corrected iPS cells by using exome sequencing. Outcome from this project would bring iPS cell technology one step closer to clinical applications.

  Study EGAS00001000055

• Acute_Lymphoblastic_Leukemia_Sequencing

  Agilent whole exome hybridisation capture will be performed on genomic DNA derived from 50 Acute Lymphoblastic Leukemia samples and matched normal DNA from the same patients. Three lanes of Illumina GA sequencing will be performed on the resulting 100 exome libraries and mapped build 37 of the human reference genome to facilitate the identification of novel cancer genes. In addition, 500bp, NO_PCR total genomic libraries will be prepared from the same samples and five lanes of Illumina GA sequencing will be analysed to characterise genome wide, somatically acquired structural variation.

  Study EGAS00001000058

• Somatic_mutation_and_clonal_evolution_in_the_human_bladder_WES_NOVASEQ

  n this study, we aim to characterise the landscape of mutation and clonal selection in the human bladder. The study includes targeted sequencing of laser-dissected microbiopsies from the bladder. The samples utilised in this study will include urothelium from transplant donors with no history of bladder cancer and cystectomy specimens from patients with bladder cancer.

  Study EGAS00001003456

• Intra-tumor heterogeneity of localized lung adenocarcinomas defined by multi-region sequencing

  Background: Intra-tumor heterogeneity (ITH) may have profound impacts on biopsy strategy, characterization of actionable targets, treatment planning, and drug resistance. ITH of lung cancers has not been well studied. Methods: We performed multi-region whole exome sequencing (average sequencing depth 277x) on 48 tumor regions from 11 resected lung adenocarcinomas (8 stage I, 2 stage II and one stage III tumors) followed by deep sequencing validation (average sequencing depth 863x). Results: All tumors showed clear evidence of spatial ITH. On average, 76% of all mutations and 20/21 known cancer gene mutations were present in all regions of individual tumors (trunk mutations). Copy number analysis did not show substantial difference in large-scale chromosome aberrations. A canonical KRAS p.G12C mutation was detected in only 1 of 4 tumor regions (branch mutations) at exome depth but detected in all four tumor regions (trunk mutations) at increased sequencing depth. In addition, many heterogeneous branch mutations defined by exome sequencing were detectable in all regions of individual tumors with increasing sequencing depth. Significant differences in mutational spectrum were observed in 6 tumors indicating that specific mutational processes were likely operative at different times during development of these tumors. With a median follow up of 21 months post surgery, 3 patients have relapsed and all 3 patients presented with significantly larger fractions of subclonal mutations in their primary tumors. Conclusions: Although multi-region sampling is still required to fully assess ITH complexity, single biopsy analysis at appropriate depth might be sufficient to identify the majority of known cancer gene mutations in localized lung adenocarcinomas. Larger subclonal mutation fractions may be associated with increased likelihood of postsurgical relapse in patients with localized lung adenocarcinomas. Studies on larger cohort, ideally with comprehensive clinical annotation and repeat biopsy at relapse are needed to fully understand the clinical impact of ITH.

  Study EGAS00001000930

• Ischemic stroke in a Swedish case-control study.

  Background. Genetic risk scores (GRS), summing up the total effect of several single nucleotide polymorphisms (SNPs) in genes associated with either coronary risk or cardiovascular risk factors, have been tested for association with ischemic stroke with conflicting results. Recently an association was found between a GRS, based on 29 SNPs discovered by genome-wide association studies (GWAS) and hypertension. The aim of our study was to investigate the possible association of the same GRS with ischemic stroke on top of other “traditional risk factors”, also testing its potential improvement in indices of discrimination and reclassification, in a Swedish case-control study. Methods and results. Twenty-nine SNPs were genotyped in 3,677 stroke cases and 2,415 controls included in the Lund Stroke Register (LSR), the Malmö Diet and Cancer (MDC) study and the Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS). The analysis was conducted in the entire material, and separately for the three samples. After adjustment for hypertension, diabetes mellitus and smoking habits, the GRS was associated with ischemic stroke in the entire material [OR (95% CI) 1.086 (1.029-1.147) per SD increase in the GRS p=0.003] with similar trends in all three samples; LSR [1.050 (0.967-1.140)]; p=0.25], MDC [1.168 (1.060-1.288); p=0.002] and SAHLSIS [1.124 (0.997-1.267); P=0.055]. Measures of discrimination and reclassification improved marginally using the GRS. Conclusions. A blood pressure GRS is independently associated with ischemic stroke risk in three Swedish case-control studies, however, the effect size is low and adds marginally to prediction of stroke on top of traditional risk factors including hypertension.

  Study EGAS00001000936

• Bulk-RNA Sequencing of high-grade pancreatic and non-pancreatic Neuroendocrine Neoplasms

  Therapeutic decisions in oncology depend on a precise pathological classification of individual neoplasms. Recent years have seen an intensification of research activities aimed at the extraction of clinically relevant information from patient-derived 'omics' data based on Machine-Learning models. However, a comprehensive training of Machine-Learning models requires sufficiently large numbers of training samples, which are usually not available for rare cancer types. The problem is worsened when individual tissues segregate into different cancer subtypes, as their discrimination would require even more training samples. Methods: Here, we report on a new data-augmentation technique to support the training of Machine-Learning models on ‘omics’ data from pancreatic neuroendocrine neoplasms (panNEN). PanNENs display all properties described above: Only about 2-3% of all pancreatic neoplasms are neuroendocrine and they fall into different subtypes with distinctly different prognosis, which makes the precise classification of such samples both difficult and important for therapy decisions. The approach reconstructs a given transcriptome based on healthy pancreatic cell type signatures and creates a Machine-Learning model that integrates the observed reconstruction error and predicted cell type proportions as features. Results: A benchmark of the deconvolution model predictions with the ground-truth found that the model could efficiently predict the sample grading, disease-related patient survival time, and differentiate between different subtypes in four panNEN and one mixed panNEN and non-pancreatic NENs dataset. We compared the predictive performance of the deconvolution-trained model to that of a model trained directly on the transcriptomic data, under inclusion of the Ki-67 classification gold standard biomarker, and found the performances to be comparable. Conclusion: Our approach serves as a data-augmentation technique to facilitate the training of Machine Learning models for rare cancer types via utilization of data from healthy origin. Additionally, the deconvolution results were clinically interpretable and further research can render the deconvolution approach an effective complementary asset for the clinical classification of neoplasms.

  Study EGAS00001004861

• Genetic makeup of agnospheres

  Agnospheres are cultures of cancer stem cells isolated from tissue biopsies from patients with Cancer of Unknown Primary (CUPs). The latter is a lethal malignancy (median survival <1 year), representing approximately the 3% of all cancers, and characterized by metastatic dissemination in the absence of a primary tumor recognizable by a standardized protocol including thorough body imaging and histopathological analysis. Agnospheres are long-term propagated in culture and, after subcutaneous injection into immunocompromised mice, they display high tumorigenicity and quickly reproduce the clinical presentation of the original tumor, featuring a multi-organ metastatic pattern and poorly differentiated histology. The goal of the project is to analyse the mutational profile of agnospheres in detail, as to verify its correspondance with that of the original tumors. Genetic information will be exploited to investigate the genetic drivers of the CUP phenotype, in particular the hypermetastatic ability and the differentiative block.

  Study EGAS00001004868

• DKFZ-HIPO Project H021/NCT MASTER

  Clinical genome and transcriptome sequencing in younger adults with advanced-stage cancer across all histologies: DKFZ-HIPO Project H021 (http://www.hipo-heidelberg.org/hipo2/index.php/menu-item-2/32-021-prospective-genetic-characterization-of-tumors-from-individual-patients-of-special-interest) / NCT MASTER (http://www.nct-heidelberg.de/forschung/nct-master.html)

  Study EGAS00001000948

• Colorectal_organoids_and_tumour_tissue___Whole_Genome_X10

  Whole genome sequencing of single cell derived organoids from normal colon tissue and colorectal cancer.

  Study EGAS00001001100

• High-resolution structural genomics reveals new therapeutic vulnerabilities in glioblastoma

  We investigated the role of 3D genome architecture in instructing functional properties of glioblastoma stem cells (GSCs) by generating the highest-resolution 3D genome maps to-date for this cancer. Integration of DNA contact maps with chromatin and transcriptional profiles identified specific mechanisms of gene regulation, including individual physical interactions between regulatory regions and their target genes. Residing in structurally conserved regions in GSCs was CD276, a gene known to play a role in immuno-modulation. We show that, unexpectedly, CD276 is part of a stemness network in GSCs and can be targeted with an antibody-drug conjugate to curb self-renewal, a key stemness property. Our results demonstrate that integrated structural genomics datasets can be employed to rationally identify therapeutic vulnerabilities in self-renewing cells.

  Study EGAS00001003493

• Combined hereditary and somatic mutations of replication error repair genes result in rapid onset of ultra-hypermutated cancers

  DNA replication-associated mutations are repaired by two components: polymerase proofreading and mismatch repair. The mutational consequences of disruption to both repair components in humans are not well studied. We sequenced cancer genomes from children with inherited biallelic mismatch repair deficiency (bMMRD). High-grade bMMRD brain tumors exhibited massive numbers of substitution mutations (>250/Mb) – higher than all childhood and most cancers (>7000 analyzed). All ultra-hypermutated bMMRD cancers acquired early somatic driver mutations in DNA polymerases epsilon or delta. The ensuing mutation signatures and numbers are unique and diagnostic of childhood germline bMMRD (p<10e-13). Sequential tumor biopsy analysis revealed that bMMRD/polymerase mutant cancers rapidly amass an excess of simultaneous mutations (~600 mutations/cell division), reaching but not exceeding ~20,000 exonic mutations in <6 months. Thus implying a threshold compatible with cancer cell survival. We suggest a new mechanism of cancer progression in which mutations develop in a rapid burst after ablation of replication repair.

  Study EGAS00001001112