Genome variation profiling by array Genome variation profiling by genome tiling array
Summary
Purpose: Small bowel adenocarcinoma (SBA) is a rare cancer and consequently the number of clinical trials has been very limited due to the small numbers of patients. Chemotherapy regimens are currently rather arbitrarily chosen between either a colorectal (CRC) or a gastric cancer (GC) regimen. Chromosomal copy number aberrations are a hallmark of solid tumours and can be measured by array comparative genomic hybridization (aCGH). The aim of the present study is to investigate whether genome-wide copy number aberrations of SBA are more similar to CRC or GC in order to support treatment of SBA according to either regimen. Experimental Design: A total of 85 GCs, CRCs and SBAs were selected from existing in house aCGH datasets based on array quality and clinical parameters. Differences and similarities in gains and losses of the three tumor types were analyzed using supervised and unsupervised analysis. Results: Hierarchical clustering revealed substantial overlap of chromosomal copy number profiles between SBA and CRC and less overlap between SBA and GC. Chromosome 13q13.2-q31.3 is primarily gained in SBA and CRC and the strongest feature discriminating SBA from GC. Further strong discriminating copy number characteristics are aberrations at chromosomes 1p36.3-p34.3, 4p15.3-q35.2, 9p24.3-p11.1 and 17p13.3-p13.2. Conclusions: SBA is more similar to CRC than to GC, based on genome-wide copy number aberrations. These data provide molecular support for treatment of SBA according to a CRC regimen.
Overall design
29 gastric adenocarcinomas on 5K or 6K BAC arrays of which 2 samples are also done on 30K oligonucleotide arrays as control samples, 29 colorectal adenocarcinomas on 5K or 6K BAC arrays of which 2 samples are also done on 30K oligonucleotide arrays as control, 27 small bowel adenocarcinomas done on 30K oligonucleotide arrays of which 2 samples are also done on 5K BAC arrays as control.