title: Human papillomavirus DNA is rarely detected in colorectal carcinomas and not associated with microsatellite instability: the Seattle colon cancer family registry.
abstract: BACKGROUND
  Persistent infection with oncogenic human papillomavirus (HPV) types-16 and -18 is an established cause of cervical and other cancers. Some studies report detection of oncogenic HPV DNA in colorectal carcinomas, with prevalence estimates as high as 84%. However, other studies report detecting no HPV DNA in colorectal tumors.
  
  
  METHODS
  To evaluate the prevalence of HPV in colorectal cancer subsets, we conducted a case-case comparison study. This study included 555 cases of incident colorectal cancer from the Seattle Colon Cancer Family Registry (CCFR), ages 20 to 74 years and diagnosed between 1998 and 2002. Standardized interviews were used to elicit demographics and risk factor data. Tumor DNA was assayed for HPV-16 and -18 DNA using real-time PCR. Microsatellite instability (MSI) status was assessed using a standard 10-marker panel and confirmed with immunohistochemical staining. Prevalence estimates were calculated for the overall sample, and stratified by patient and tumor characteristics. Fisher exact test was used to compare prevalence between strata.
  
  
  RESULTS
  HPV-16 DNA was detected in 2% of colorectal tumors, but no HPV-18 DNA was detected. HPV-16 prevalence did not vary between cases according to sex, age, race, smoking-status, or MSI-status (P > 0.05). HPV-16 prevalence in rectal carcinomas was 5% compared with 1% in colon carcinomas (P = 0.03).
  
  
  CONCLUSIONS
  Among a large sample of colorectal carcinomas, prevalence of HPV-16 and -18 was very low. Prior studies detecting high HPV prevalence in colorectal carcinomas are likely the result of contamination from the anal canal or clinical processing.
  
  
  CONCLUSIONS
  HPV is unlikely to play a large role in colorectal carcinogenesis.
authors.affiliation: Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA. aburnett@fhcrc.org
authors.forename: Andrea N
authors.initials: AN
authors.lastname: Burnett-Hartman
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Feng
authors.forename: Viorica
authors.initials: V
authors.lastname: Popov
authors.forename: Anisha
authors.initials: A
authors.lastname: Kalidindi
authors.forename: Polly A
authors.initials: PA
authors.lastname: Newcomb
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000821:virology; D004279:DNA, Viral / Q000235:genetics; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D053842:Microsatellite Instability; D008875:Middle Aged; D027383:Papillomaviridae / Q000235:genetics*; D030361:Papillomavirus Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000821:virology; D016133:Polymerase Chain Reaction; D011379:Prognosis; D012042:Registries; D012307:Risk Factors; D014412:Tumor Virus Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000821:virology; D055815:Young Adult
chemical_list: D004279:DNA, Viral