Colorectal advanced adenomas NKI-AvL TGO COCOS series
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ABSTRACT:
PROVIDER: EGAS00001002952 | EGA |
REPOSITORIES: EGA
Similar Datasets
Project description:Colorectal cancer (CRC) develops from normal epithelium, through a benign precursor lesion called adenoma, by accumulation of genetic alterations affecting oncogenes and tumour suppressor genes. About 5% of colorectal adenomas are estimated to progress to CRC. However, it is important to identify which adenomas actually are at high-risk of progression, because these should serve as intermediate endpoints for e.g. CRC screening programs. In clinical practice, adenomas with a size of ≥10 mm, villous component and/or high-grade dysplasia, called advanced adenomas, are considered high-risk, although this classification lacks solid evidence. Specific DNA copy number changes are associated with adenoma-to-carcinoma progression.For this tissue dataset, we applied low-pass whole genome sequencing to 98 non-advanced and advanced adenomas. These adenomas were classified as lesions with low-risk or high-risk of progression, according to the presence of specific DNA copy number changes (Carvalho et al, CancerPrevRes, 2018).
| EGAS00001002953 | EGA
Project description:"Background & Aims: Current morphological features defining advanced adenomas (size ≥10 mm, high grade dysplasia or >25% villous component) cannot optimally distinguish individuals at high-risk or low-risk of metachronous colorectal cancer (me-CRC), which may result in suboptimal surveillance. Certain DNA copy number alterations are associated with adenoma-to-carcinoma progression (cancer-associated events; CAEs). We aimed to evaluate whether CAEs can better predict an individual’s risk of me-CRC than the morphological advanced adenoma features.
Methods: In this nested case-control study, 529 individuals with a single adenoma at their first colonoscopy were selected from a Norwegian adenoma cohort. DNA copy number profiles were determined, by means of low-coverage whole genome sequencing. We assessed the prevalence of CAEs in advanced and non-advanced adenomas and its association with me-CRC. For the latter, cases (with CRC) were matched to controls (without CRC), with the same follow-up period as cases, as well as age and sex. Subsequently, odds ratios (OR) for the association of the presence of an advanced adenoma or a molecularly-defined high-risk adenoma with me-CRC were calculated.
Results: Molecular high-risk features were observed in 85/267 (32%) of advanced adenomas and in 27/262 (10%) of non-advanced adenomas. Me-CRC was more strongly associated with advanced adenomas (OR 3.58; 95% CI 2.27-5.72) than with molecular high-risk adenomas (OR 1.90; 95% CI 1.14–3.16). After adjusting for other variables, only advanced adenoma remained significantly associated with me-CRC (OR 3.39; 95% CI 2.10–5.55).
Conclusion: Molecularly-defined high-risk adenomas were associated with me-CRC, but the association of advanced adenoma with me-CRC was stronger. "
Project goal: Evaluate the value of DNA copy numbers alterations detected in a baseline adenoma, in the prediction of risk of metachronous CRC
| EGAS00001007039 | EGA
Project description:Approximately two decades ago, Vogelstein and Fearon proposed the adenoma-carcinoma sequence of sporadic CRC development and illustrated the accumulation of genetic alterations during the stepwise progression, thereby providing a guideline for clinical practice. Although the detection and excision of precancerous lesions could prevent colorectal cancer and reduce mortality, 6% of adenomas will ultimately develop into colorectal cancer. Thus, this genetic model for colorectal tumorigenesis may not completely reflect the complex essence of the disease and whether the mode of initiation of the events in the multistep progression affects the outcome of CRC is still unknown. In this study, mRNA and miRNA expression profiling was performed with human colorectal tissues, including normal mucosa, adenoma and adenocarcinoma. Then, an integrated approach was adopted to establish the regulatory interaction networks that were correlated with colorectal carcinogenesis. Finally, a 55-gene signature whose expression was down-regulated in precancerous lesions compared to normal tissue was identified as a potential early indicator of CRC survival. The results suggested that genes related to immunity and homeostasis played a critical role in protection against adenoma initiation and that the altered molecular events that influence colorectal cancer prognosis may be set in an early, precancerous stage. Four types of human colorectal tissues were selected by colonoscopic resection or colorectal surgery, including 12 normal mucosae, 21 low-grade adenomas (mild or moderate atypical hyperplasia), 30 high-grade adenomas (severe atypical hyperplasia or carcinoma in situ) and 25 adenocarcinomas. Gene expression profiling analysis of these samples was performed using Agilent 4x44K human whole genome gene expression microarray (G4112F).
2015-10-16 | E-GEOD-41657 | biostudies-arrayexpress
Project description:Approximately two decades ago, Vogelstein and Fearon proposed the adenoma-carcinoma sequence of sporadic CRC development and illustrated the accumulation of genetic alterations during the stepwise progression, thereby providing a guideline for clinical practice. Although the detection and excision of precancerous lesions could prevent colorectal cancer and reduce mortality, 6% of adenomas will ultimately develop into colorectal cancer. Thus, this genetic model for colorectal tumorigenesis may not completely reflect the complex essence of the disease and whether the mode of initiation of the events in the multistep progression affects the outcome of CRC is still unknown. In this study, mRNA and miRNA expression profiling was performed with human colorectal tissues, including normal mucosa, adenoma and adenocarcinoma. Then, an integrated approach was adopted to establish the regulatory interaction networks that were correlated with colorectal carcinogenesis. Finally, a 55-gene signature whose expression was down-regulated in precancerous lesions compared to normal tissue was identified as a potential early indicator of CRC survival. The results suggested that genes related to immunity and homeostasis played a critical role in protection against adenoma initiation and that the altered molecular events that influence colorectal cancer prognosis may be set in an early, precancerous stage. Four types of human colorectal tissues were selected by colonoscopic resection or colorectal surgery, including 15 normal mucosae, 39 low-grade adenomas (mild or moderate atypical hyperplasia), 20 high-grade adenomas (severe atypical hyperplasia or carcinoma in situ) and 33 adenocarcinomas. MicroRNA expression profiling analysis of these samples was performed on Agilent 8Ã16K Human miRNA Microarray V3 (G4470C).
2015-10-16 | E-GEOD-41655 | biostudies-arrayexpress
Project description:Chromosomal instability (CIN) is the hallmark of colorectal adenoma to carcinoma progression in 85% of cases, with 20q gain as the most prominent aberration. Yet, the oncogenes at this chromosomal gain are still largely unknown. Here, we aimed to identify oncogenes at 20q involved in colorectal adenoma to carcinoma progression by measuring the effect of 20q gain on gene expression in this amplicon. Segmentation of DNA copy number changes on 20q was performed by array CGH in 67 colorectal adenomas and carcinomas. Additionally, robust analysis of mRNA expression in these segments was performed in 68 adenomas and carcinomas. This approach revealed seven genes to be important in CIN related adenoma to carcinoma progression. These genes may both serve as highly specific biomarkers for presence of high-risk precursor lesions as well as potential targets for pharmaceutical intervention. Keywords: Integration of array CGH and expression microarrays in colorectal cancer progression We performed array CGH on a panel of 41 progressed adenomas, from which the adenoma and carcinoma components were separately analysed (total, 82 samples). The DNA obtained from these samples was extracted from formalin-fixed, paraffin-embedded material. Additionally we analysed a series of independent frozen adenomas and carcinomas by array CGH (34 adenomas and 33 carcinomas) and expression microarrays (37 adenomas and 31 carcinomas). For array-CGH we used as reference DNA for all samples, a pool of 10 normal individuals. For expression microarrays we used as reference a commercial available RNA (pool of different cancer cell lines), from Strategene. No replicates nor dye swaps were done.
2010-06-25 | E-GEOD-8067 | biostudies-arrayexpress
Project description:Chromosomal instability (CIN) is the hallmark of colorectal adenoma to carcinoma progression in 85% of cases, with 20q gain as the most prominent aberration. Yet, the oncogenes at this chromosomal gain are still largely unknown. Here, we aimed to identify oncogenes at 20q involved in colorectal adenoma to carcinoma progression by measuring the effect of 20q gain on gene expression in this amplicon. Segmentation of DNA copy number changes on 20q was performed by array CGH in 67 colorectal adenomas and carcinomas. Additionally, robust analysis of mRNA expression in these segments was performed in 68 adenomas and carcinomas. This approach revealed seven genes to be important in CIN related adenoma to carcinoma progression. These genes may both serve as highly specific biomarkers for presence of high-risk precursor lesions as well as potential targets for pharmaceutical intervention. Keywords: Integration of array CGH and expression microarrays in colorectal cancer progression
2008-10-15 | GSE8067 | GEO
Project description:Aberrant methylation of DNA is supposed to be a major and early driver of colonic adenoma development and may also lead to colorectal cancer (CRC) formation. While gene methylation assays are used already for CRC screening, differential epigenetic alterations of recurring and non-recurring colorectal adenomas have yet not been systematically investigated. Here, we collected a sample set (n=72) of formalin-fixed paraffin-embedded (FFPE) primary colorectal adenomas without recurrence (n=30), primary adenomas with recurrence at the same location (n=19), so-called “matched pair samples” (n=10; comprising the primary adenoma and the recurrent adenoma) and normal mucosa specimens (n=3). We aimed to unveil differentially methylated CpG positions (DMPs) across the methylome of the selected samples using the Illumina HumanMethylation 450K BeadChip array. Unsupervised hierarchical clustering exhibited a significant association of methylation patterns with the histological subtypes. No significant DMPs were identified comparing primary adenomas with and without recurrence. Despite that, a total of 5,094 DMPs (FDR<0.05, fold change>10%) were identified in the comparisons of recurrent adenomas vs. (non-) matched primary adenomas with recurrence (674; 98% hypermethylated), recurrent adenomas vs. primary adenomas with and without recurrence (241; 99% hypermethylated) and adenomas vs. normal mucosae (4,179; 46% hypermethylated). DMPs in CpG islands were frequently hypermethylated whereas open sea and shelves exhibited hypomethylation. Gene ontological analysis demonstrated enrichment of genes associated with the immune system, inflammatory processes, and cancer-pathways. We conclude that methylation data is helpful to contribute to a more stable and reproducible histological adenoma classification which is a prerequisite to establishing profound surveillance guidelines
2019-06-01 | GSE129364 | GEO
Project description:The colorectal adenoma-carcinoma sequence describes the stepwise progression from normal to dysplastic epithelium and then to carcinoma; only a small proportion of colorectal adenoma (CRA) progresses to colorectal carcinoma (CRC). Presently, endoscopic intervention is used on patients with CRAs of high grade dysplasia, diameters > 1 cm, or villous components > 25% who are at higher risk than other CRA sufferers. During the process, biopsy samples were taken for conventional histological diagnosis, but poor pathomorphological sensitivity and specificity greatly limit the diagnostic accuracy. Unfortunately, there are no reliable molecular criteria available that can predict the potential development of CRA to CRC. In present study, we use microarrays to detail the global programme of gene expression underlying the gradual progress of colorectal adenoma-carcinoma sequence.
2010-08-29 | GSE22242 | GEO
Project description:Colorectal adenomas are benign precursor lesions of colorectal cancer (CRC) that arise from normal epithelium1. The prevalence of adenomas in the large intestine is much higher than the incidence of cancer implying that the majority of adenomas will never progress to CRC4. In clinical practice, adenomas detected during colonoscopy are completely removed, and consequently the natural history of disease disrupted. Based on the prevalence of focal cancer in endoscopically removed adenomas, it is estimated that only 5% of adenomas will eventually progress to CRC. The aim of the present study was to characterize adenomas at low and high risk of progressing to cancer by extensive molecular profiling at DNA, RNA, and protein level, allowing to examine the biological processes in which they differ and to discover putative drivers of early colorectal tumor development.
2019-08-22 | PXD012254 | Pride
Project description:Approximately two decades ago, Vogelstein and Fearon proposed the adenoma-carcinoma sequence of sporadic CRC development and illustrated the accumulation of genetic alterations during the stepwise progression, thereby providing a guideline for clinical practice. Although the detection and excision of precancerous lesions could prevent colorectal cancer and reduce mortality, 6% of adenomas will ultimately develop into colorectal cancer. Thus, this genetic model for colorectal tumorigenesis may not completely reflect the complex essence of the disease and whether the mode of initiation of the events in the multistep progression affects the outcome of CRC is still unknown. In this study, mRNA and miRNA expression profiling was performed with human colorectal tissues, including normal mucosa, adenoma and adenocarcinoma. Then, an integrated approach was adopted to establish the regulatory interaction networks that were correlated with colorectal carcinogenesis. Finally, a 55-gene signature whose expression was down-regulated in precancerous lesions compared to normal tissue was identified as a potential early indicator of CRC survival. The results suggested that genes related to immunity and homeostasis played a critical role in protection against adenoma initiation and that the altered molecular events that influence colorectal cancer prognosis may be set in an early, precancerous stage.
2015-10-16 | GSE41657 | GEO