title: Increased Risk of Colorectal Cancer Development Among Patients With Serrated Polyps.
abstract: OBJECTIVE
  Sessile serrated adenomas/polyps (SSA/Ps) and traditional serrated adenomas (TSAs) are now distinguished from hyperplastic polyps and recognized as precursors to colorectal cancer (CRC). We studied CRC risks associated with serrated polyps.
  
  
  METHODS
  By using Danish databases (1977-2009), we conducted a nationwide population-based, case-control study nested within individuals who had received colonoscopies (n = 272,342), and identified 2045 CRC cases and 8105 CRC-free individuals (controls). For each case and control, we identified the first colorectal polyp(s) that underwent a biopsy or were excised during or after the initial colonoscopy, and obtained tissue blocks for hyperplastic lesions. Four expert pathologists reviewed these lesions using current terminology for serrated polyps. We used logistic regression to compute odds ratios (ORs) to associate the risk of CRC with polyp type and estimated the absolute risks by multiplying the risk in patients with no polyps by these ORs.
  
  
  RESULTS
  Seventy-nine cases and 142 controls had SSA/Ps (OR, 3.07; 95% confidence interval [CI], 2.30-4.10). SSA/Ps with cytology markers of dysplasia were associated with a particularly high OR (4.76; 95% CI, 2.59-8.73). Women with SSA/P had a higher risk for CRC than men with SSA/P (OR for women, 5.05; 95% CI, 3.05-8.37 vs OR for men, 2.18; 95% CI, 1.24-3.82); patients with SSA/P proximal to the splenic flexure had the highest risk for CRC (OR, 12.42; 95% CI, 4.88-31.58). The OR for CRC was 4.84 in the 14 cases vs 17 controls with TSAs (95% CI, 2.36-9.93), 2.51 in the 757 cases vs 1698 controls with conventional adenomas (95% CI, 2.25-2.80), and 1.30 in the 55 cases vs 235 controls with hyperplastic polyps (95% CI, 0.96-1.77). The 10-year risk for CRC was 4.4% for patients with SSA/P with dysplasia, 4.5% for patients with TSAs, and 2.3% for patients with conventional adenomas.
  
  
  CONCLUSIONS
  Patients with SSA/P or TSA are at increased risk for CRC; their level of risk is similar to or higher than that of patients with conventional adenomas.
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N, Denmark. Electronic address: re@clin.au.dk.
authors.forename: Rune
authors.initials: R
authors.lastname: Erichsen
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N, Denmark; Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina.
authors.forename: John A
authors.initials: JA
authors.lastname: Baron
authors.affiliation: Institute of Pathology, Aarhus University Hospital, Aarhus C, Denmark.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Hamilton-Dutoit
authors.affiliation: Department of Pathology, Fairview Southdale Hospital, Edina, Minnesota.
authors.forename: Dale C
authors.initials: DC
authors.lastname: Snover
authors.affiliation: Department of Pathology, University Health Network, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Emina Emilia
authors.initials: EE
authors.lastname: Torlakovic
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N, Denmark.
authors.forename: Lars
authors.initials: L
authors.lastname: Pedersen
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N, Denmark.
authors.forename: Trine
authors.initials: T
authors.lastname: Frøslev
authors.affiliation: Institute of Pathology, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Mogens
authors.initials: M
authors.lastname: Vyberg
authors.affiliation: Division of Pathology and Laboratory Medicine, University of Texas M.D. Anderson Cancer Center, Houston, Texas.
authors.forename: Stanley R
authors.initials: SR
authors.lastname: Hamilton
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N, Denmark; Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina.
authors.forename: Henrik Toft
authors.initials: HT
authors.lastname: Sørensen
mesh_terms: D018256:Adenomatous Polyps / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D016022:Case-Control Studies; D003082:Colectomy; D003111:Colonic Polyps / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000473:pathology*; D003718:Denmark / Q000453:epidemiology; D018450:Disease Progression; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011230:Precancerous Conditions / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery; D011237:Predictive Value of Tests; D012004:Rectal Neoplasms / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors
keywords: Colorectal Neoplasm; Early Detection; Risk Factor; Tumor