title: Association between human Papillomavirus and colorectal adenocarcinoma and its influence on tumor staging and degree of cell differentiation.
abstract: BACKGROUND
  Colorectal cancer is one of the most common types of neoplasia among the worldwide adult population. Among neoplasms of the gastrointestinal tract, it is ranked second in relation to prevalence and mortality, but its etiology is only known in around 5% of the cases. It is believed that 15% of malignant diseases are related to viral oncogenesis.
  
  
  OBJECTIVE
  To correlate the presence of HPV with the staging and degree of cell differentiation among patients with colorectal adenocarcinoma.
  
  
  METHODS
  A retrospective case-control study was conducted on 144 patients divided between a test group of 79 cases of colorectal cancer and a control group to analyze 144 patients aged 25 to 85 years (mean, 57.85 years; standard deviation, 15.27 years and median, 58 years). Eighty-six patients (59.7%) were male. For both groups, tissue samples from paraffin blocks were subjected to DNA extraction followed by the polymerase chain reaction using generic and specific primers for HPV 16 and 18. Dot blot hybridization was also performed with the aim of identifying HPV DNA.
  
  
  RESULTS
  The groups were shown to be homogenous regarding sex, age and site of HPV findings in the samples analyzed. Out of the 41 patients with HPV, 36 (45.6%) were in the cases and five (7.7%) were in the control group (p<0.001). All the HPV cases observed comprised HPV 16, and HPV 18 was not shown in any of the cases studied. There were no significant differences in comparisons of sex, age and site regarding the presence of HPV in either of the groups. It was not observe any significant difference in relation to staging or degree of cell differentiation among the patients with colorectal cancer.
  
  
  CONCLUSIONS
  Human papillomavirus type 16 is present in individuals with colorectal carcinoma. However, its presence was unrelated to staging or degree of differentiation.
authors.affiliation: Federal University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Olavo Magalhães
authors.initials: OM
authors.lastname: Picanço-Junior
authors.affiliation: German Hospital, Institute at the Oswaldo Cruz, São Paulo, SP, Brazil.
authors.forename: Andre Luiz Torres
authors.initials: AL
authors.lastname: Oliveira
authors.affiliation: German Hospital, Institute at the Oswaldo Cruz, São Paulo, SP, Brazil.
authors.forename: Lucia Thereza Mascarenhas
authors.initials: LT
authors.lastname: Freire
authors.affiliation: Ophyr Loiola Hospital, Belém, PA, Brazil.
authors.forename: Rosangela Baia
authors.initials: RB
authors.lastname: Brito
authors.affiliation: Federal University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Luisa Lina
authors.initials: LL
authors.lastname: Villa
authors.affiliation: Federal University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Délcio
authors.initials: D
authors.lastname: Matos
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology* / Q000821:virology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002454:Cell Differentiation; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000821:virology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D027383:Papillomaviridae / Q000302:isolation & purification*; D012189:Retrospective Studies