title: Small bowel adenocarcinoma copy number profiles are more closely related to colorectal than to gastric cancers.
abstract: BACKGROUND
  Small bowel adenocarcinoma (SBA) is a rare cancer and consequently, the options for clinical trials are limited. As they are treated according to either a colorectal or a gastric cancer regimen and the molecular biology of a tumor is a pivotal determinant for therapy response, chromosomal copy number aberrations were compared with the colorectal and gastric adenocarcinomas.
  
  
  METHODS
  A total of 85 microsatellite stable (MSS) adenocarcinomas from the stomach, colorectum and small bowel were selected from existing array comparative genomic hybridization (aCGH) datasets. We compared the aCGH profiles of the three tumor sites by supervised analysis and hierarchical clustering.
  
  
  RESULTS
  Hierarchical clustering revealed substantial overlap of 27 SBA copy number profiles with matched colorectal adenocarcinomas but less overlap with profiles of gastric adenocarcinomas. DNA copy number aberrations located at chromosomes 1p36.3-p34.3, 4p15.3-q35.2, 9p24.3-p11.1, 13q13.2-q31.3 and 17p13.3-p13.2 were the strongest features discriminating SBAs and colorectal adenocarcinomas from gastric adenocarcinomas.
  
  
  CONCLUSIONS
  We show that MSS SBAs are more similar to colorectal than to gastric cancer, based on the 27 genome-wide DNA copy number profiles that are currently available. These molecular similarities provide added support for treatment of MSS small bowel cancers according to colorectal cancer regimens.
authors.affiliation: Department of Pathology, VU University Medical Center, Amsterdam.
authors.forename: J C
authors.initials: JC
authors.lastname: Haan
authors.forename: T E
authors.initials: TE
authors.lastname: Buffart
authors.forename: P P
authors.initials: PP
authors.lastname: Eijk
authors.forename: M A
authors.initials: MA
authors.lastname: van de Wiel
authors.forename: W N
authors.initials: WN
authors.lastname: van Wieringen
authors.forename: P D
authors.initials: PD
authors.lastname: Howdle
authors.forename: C J J
authors.initials: CJ
authors.lastname: Mulder
authors.forename: C J
authors.initials: CJ
authors.lastname: van de Velde
authors.forename: P
authors.initials: P
authors.lastname: Quirke
authors.forename: I D
authors.initials: ID
authors.lastname: Nagtegaal
authors.forename: N C T
authors.initials: NC
authors.lastname: van Grieken
authors.forename: H
authors.initials: H
authors.lastname: Grabsch
authors.forename: G A
authors.initials: GA
authors.lastname: Meijer
authors.forename: B
authors.initials: B
authors.lastname: Ylstra
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics*; D015179:Colorectal Neoplasms / Q000235:genetics; D056915:DNA Copy Number Variations; D006801:Humans; D007414:Intestinal Neoplasms / Q000235:genetics*; D007421:Intestine, Small; D018895:Microsatellite Repeats; D009693:Nucleic Acid Hybridization; D013274:Stomach Neoplasms / Q000235:genetics*