Genomic profiling of stage II and III colon cancers reveals APC mutations to be associated with survival in stage III colon cancer patients
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE75500 | GEO | 2016/10/10
SECONDARY ACCESSION(S): PRJNA304433
REPOSITORIES: GEO
Similar Datasets
Project description:Analysis of expression profiles in stage II colon cancer according to the APC gene status
2011-01-28 | GSE26906 | GEO
Project description:Chromosomal instable colorectal cancer is marked by specific large chromosomal copy number aberrations. Recently, focal aberrations of 3Mb or smaller have been identified as a common phenomenon in cancer. Inherent to their limited size, these aberrations harbour one or few genes. The aim of this study is to identify recurrent focal chromosomal aberrations and their candidate driver genes in a well defined series of stage II colon cancers and assess their potential clinical relevance. High resolution DNA copy number profiles were obtained from 38 formalin fixed paraffin embedded colon cancer samples with matched normal mucosa as a reference using array comparative genomic hybridization. In total, 81 focal chromosomal aberrations were identified that harboured 177 genes. Statistical validation of focal aberrations and identification of candidate driver genes was performed by enrichment analysis and mapping copy number and mutation data of colorectal-, breast-, pancreatic cancer and glioblastomas to loci of focal aberrations in stage II colon cancer. This analysis demonstrated a significant overlap with previously identified focal amplifications in colorectal cancer, but not with cancers from other sites. In contrast, focal deletions seem less tumour type specific since they also show significant overlap with focal deletions of other sites. Focal deletions detected are significantly enriched for cancer genes and genes frequently mutated in colorectal cancer. The mRNA expression of these genes is significantly correlated with DNA copy number status, supporting the relevance of focal aberrations. Loss of 5q34 and gain of 13q22.1 were identified as independent prognostic factors of survival in this series of patients. In conclusion, focal chromosomal copy number aberrations in stage II colon cancer are enriched in cancer genes which contribute to and drive the process of colorectal cancer development. DNA copy number status of these genes correlate with mRNA expression and some are associated with clinical outcome. 38 Stage II colorectal cancer (CRC) tissue samples (FFPE) of which 19 were done on expression arrays. One sample (Stage II colorectal cancer tissue samples (FFPE) 26) was also done on the 135K NimbleGen array. Fresh frozen and FFPE of the same CRC stage I sample was done on 105K agilent. The fresh frozen was across array in silico set out against a pool of blood of 18 healthy females.
2010-04-19 | E-GEOD-17047 | biostudies-arrayexpress
Project description:Analysis of expression profiles in stage II colon cancer according to the APC gene status retrospective study
2011-01-28 | E-GEOD-26906 | biostudies-arrayexpress
Project description:Purpose: The present study aimed to develop a classification model to predict recurrence in stage II and III colon cancer, using a previously published 128-gene signature on external and independent material. Experimental Design: Microarray gene expression data from 148 patients (37 Danish patients and 111 patients retrieved from the Gene Expression Omnibus, GSE17536) with stage II and III colon cancer were analyzed using Affymetrix Arrays (Affymetrix, Santa Clara, USA). Based on a known 128-gene signature, a classification model was created with the random forest method, using a training set consisting of stage I colon cancers (with localized disease and a good prognosis) and stage IV colon cancers (with metastasis and a poor prognosis). The classifier were built to predict stage II and III colon cancers as either stage I-like (good prognosis) or stage IV-like (poor prognosis). Results: The 3-year relapse-free survival probability (RFS) of stage III patients predicted to have a good prognosis was 79% compared to 55% of patients with a poor prognosis (P = 0.177, log-rank test). The classification model could not stratify stage II colon cancer. The complete dataset representing: (1) the 37 Danish patients (2) the 111 patients retrieved from Series GSE17536 (re-used data), is linked below as a supplementary file. Tumor samples were obtained from 37 patients with stage II and III colon cancer, who underwent colon resection at the Department of Surgery, Roskilde Hospital, Denmark and the Department of Surgery, Bispebjerg Hospital, Denmark between 2001 and 2008. Purified tumor RNA was reverse-transcribed, labelled and hybridized to Affymetrix Human Genome U133 Plus 2.0 GeneChip Array (Affymetrix, Santa Clara, USA) according to the manufacturers instructions and scanned at the RH Microarray Center, Rigshospitalet, University of Copenhagen.
2011-08-31 | E-GEOD-31595 | biostudies-arrayexpress
Project description:Background: Around 30% of all stage II colon cancer patients will relapse and die of their disease. At present no objective parameters for identification of high-risk stage II colon cancer patients, who will benefit from adjuvant chemotherapy, are established. With traditional histopathological features definition of high-risk stage II colon cancer patients is inaccurate. Therefore more objective and robust markers for prediction of relapse are needed. DNA copy number aberrations have proven to be robust prognostic markers, but have not been investigated for this specific group of patients. The aim of the present study is to identify chromosomal aberrations that can predict relapse of tumor in patients with stage II colon cancer. Materials and Methods: DNA was isolated from 40 formaldehyde fixed paraffin embedded stage II colon cancer samples with extensive clinicopathological data. Samples where hybridized using Comparative Genomic Hybridization (CGH) arrays to determine DNA copy number changes and microsatellite stability was determined by PCR. To analyze differences between stage II colon cancer patients with and without relapse of tumor a Wilcoxon rank-sum test was implemented with multiple testing correction Results: Patients with stage II colon cancer who had relapse of disease showed significant more losses on chromosome 4, 5, 15q, 17q and 18q. When microsatellite stable (MSS) patients were analyzed separately, only losses on chromosome 4q22.1-4q35.2 predicted worse outcome in stage II colon cancer patients. No differences in clinicopathological characteristics between patients with and without relapse were observed. Conclusion: Losses on 4q22.1-4q35.2 predict worse outcome in MSS stage II colon cancer patients and may aid in the selection of patients for adjuvant therapy. 40 Stage II colorectal cancer (CRC) tissue samples (FFPE), 16 with and 24 without relapse of tumor
2010-07-13 | E-GEOD-17181 | biostudies-arrayexpress
Project description:Tumor profiling of DNA alterations, i.e. gene point mutations, somatic copy number aberrations (CNAs) and structural variants (SVs), improves insight into the molecular pathology of cancer and clinical outcome. Here, associations between genomic aberrations and disease recurrence in stage II and III colon cancers were investigated. A series of 114 stage II and III microsatellite stable colon cancer samples were analyzed by high-resolution array-comparative genomic hybridization (array-CGH) to detect CNAs and CNA-associated chromosomal breakpoints (SVs). For 60 of these samples mutation status of APC, TP53, KRAS, PIK3CA, FBXW7, SMAD4, BRAF and NRAS was determined using targeted massive parallel sequencing. Loss of chromosome 18q12.1-18q12.2 occurred more frequently in tumors that relapsed than in relapse-free tumors (p < 0.001; FDR = 0.13). In total, 267 genes were recurrently affected by SVs (FDR < 0.1). CNAs and SVs were not associated with disease-free survival (DFS). Mutations in APC and TP53 were associated with increased CNAs. APC mutations were associated with poor prognosis in (5-fluorouracil treated) stage III colon cancers (p = 0.005; HR = 4.1), an effect that was further enhanced by mutations in MAPK pathway (KRAS, NRAS, BRAF) genes. We conclude that among multiple genomic alterations in CRC, strongest associations with clinical outcome were observed for common mutations in APC.
| S-EPMC5342020 | biostudies-literature
Project description:Chromosomal instable colorectal cancer is marked by specific large chromosomal copy number aberrations. Recently, focal aberrations of 3Mb or smaller have been identified as a common phenomenon in cancer. Inherent to their limited size, these aberrations harbour one or few genes. The aim of this study is to identify recurrent focal chromosomal aberrations and their candidate driver genes in a well defined series of stage II colon cancers and assess their potential clinical relevance. High resolution DNA copy number profiles were obtained from 38 formalin fixed paraffin embedded colon cancer samples with matched normal mucosa as a reference using array comparative genomic hybridization. In total, 81 focal chromosomal aberrations were identified that harboured 177 genes. Statistical validation of focal aberrations and identification of candidate driver genes was performed by enrichment analysis and mapping copy number and mutation data of colorectal-, breast-, pancreatic cancer and glioblastomas to loci of focal aberrations in stage II colon cancer. This analysis demonstrated a significant overlap with previously identified focal amplifications in colorectal cancer, but not with cancers from other sites. In contrast, focal deletions seem less tumour type specific since they also show significant overlap with focal deletions of other sites. Focal deletions detected are significantly enriched for cancer genes and genes frequently mutated in colorectal cancer. The mRNA expression of these genes is significantly correlated with DNA copy number status, supporting the relevance of focal aberrations. Loss of 5q34 and gain of 13q22.1 were identified as independent prognostic factors of survival in this series of patients. In conclusion, focal chromosomal copy number aberrations in stage II colon cancer are enriched in cancer genes which contribute to and drive the process of colorectal cancer development. DNA copy number status of these genes correlate with mRNA expression and some are associated with clinical outcome.
2010-04-19 | GSE17047 | GEO
Project description:Prostate cancer is the most common malignancy in men. Yet, the modest benefit of treatment highlights the unmet need for prognostic biomarkers in prostate cancer (1). Few large prostate oncogenome resources currently exist that combine the molecular and clinical outcome data necessary for prognostic discovery. To determine the extent to which genomic aberrations reflect the risk of prostate cancer-specific outcomes, we profiled more than 100 primary prostate cancers with long-term follow-up for genome-wide copy number alterations (CNA). We also updated the long-term clinical outcome (median 8 years) of an additional independent cohort of 181 primary prostate cancers that we previously profiled for CNA and expression changes (2). Together, we found that CNA burden across the genome, defined as the percent of the tumor genome affected by CNA, is prognostic for recurrence and metastasis in these two cohorts. This prognostic significance of CNA is independent of Gleason grade, a major existing histopathological prognostic variable in prostate cancer. Moreover, in intermediate-risk Gleason 7 prostate cancers that show a wide range of outcomes, CNA burden is also prognostic for biochemical recurrence, independent of prostate-specific antigen or nomogram score. CNA burden therefore has the potential to stratify patients by their risk of recurrence in an otherwise intermediate risk subpopulation. We further demonstrate that CNA burden can be established in diagnostic FFPE needle biopsies using low-input whole genome sequencing. Together, this work highlights the potential of oncogenomics to identify useful and clinically amenable prognostic factors that may inform prostate cancer outcome and treatment. Human prostate samples were profiled on Agilent 1M aCGH arrays per manufacturer's instructions. A pooled reference normal DNA was used as the reference.
2014-06-30 | E-GEOD-54691 | biostudies-arrayexpress
Project description:Prostate cancer is the most common malignancy in men. Yet, the modest benefit of treatment highlights the unmet need for prognostic biomarkers in prostate cancer (1). Few large prostate oncogenome resources currently exist that combine the molecular and clinical outcome data necessary for prognostic discovery. To determine the extent to which genomic aberrations reflect the risk of prostate cancer-specific outcomes, we profiled more than 100 primary prostate cancers with long-term follow-up for genome-wide copy number alterations (CNA). We also updated the long-term clinical outcome (median 8 years) of an additional independent cohort of 181 primary prostate cancers that we previously profiled for CNA and expression changes (2). Together, we found that CNA burden across the genome, defined as the percent of the tumor genome affected by CNA, is prognostic for recurrence and metastasis in these two cohorts. This prognostic significance of CNA is independent of Gleason grade, a major existing histopathological prognostic variable in prostate cancer. Moreover, in intermediate-risk Gleason 7 prostate cancers that show a wide range of outcomes, CNA burden is also prognostic for biochemical recurrence, independent of prostate-specific antigen or nomogram score. CNA burden therefore has the potential to stratify patients by their risk of recurrence in an otherwise intermediate risk subpopulation. We further demonstrate that CNA burden can be established in diagnostic FFPE needle biopsies using low-input whole genome sequencing. Together, this work highlights the potential of oncogenomics to identify useful and clinically amenable prognostic factors that may inform prostate cancer outcome and treatment.
2014-06-30 | GSE54691 | GEO
Project description:Background: Around 30% of all stage II colon cancer patients will relapse and die of their disease. At present no objective parameters for identification of high-risk stage II colon cancer patients, who will benefit from adjuvant chemotherapy, are established. With traditional histopathological features definition of high-risk stage II colon cancer patients is inaccurate. Therefore more objective and robust markers for prediction of relapse are needed. DNA copy number aberrations have proven to be robust prognostic markers, but have not been investigated for this specific group of patients. The aim of the present study is to identify chromosomal aberrations that can predict relapse of tumor in patients with stage II colon cancer. Materials and Methods: DNA was isolated from 40 formaldehyde fixed paraffin embedded stage II colon cancer samples with extensive clinicopathological data. Samples where hybridized using Comparative Genomic Hybridization (CGH) arrays to determine DNA copy number changes and microsatellite stability was determined by PCR. To analyze differences between stage II colon cancer patients with and without relapse of tumor a Wilcoxon rank-sum test was implemented with multiple testing correction Results: Patients with stage II colon cancer who had relapse of disease showed significant more losses on chromosome 4, 5, 15q, 17q and 18q. When microsatellite stable (MSS) patients were analyzed separately, only losses on chromosome 4q22.1-4q35.2 predicted worse outcome in stage II colon cancer patients. No differences in clinicopathological characteristics between patients with and without relapse were observed. Conclusion: Losses on 4q22.1-4q35.2 predict worse outcome in MSS stage II colon cancer patients and may aid in the selection of patients for adjuvant therapy.
2010-07-13 | GSE17181 | GEO