title: Increased incidence of colorectal adenomas in follow-up evaluation of patients with newly diagnosed hyperplastic polyps.
abstract: BACKGROUND
  Although adenomatous polyps have been established clearly as precursor lesions for most cases of colorectal cancer, the role, if any, of hyperplastic polyps remains uncertain. The aim of the current study was to determine whether a patient with an index finding of hyperplastic polyp on colonoscopy is at increased risk for adenomatous polyps.
  
  
  METHODS
  We conducted a retrospective cohort study using the records of a single surgeon's colonoscopic experience over a 20-year period (June 1973 to December 1994). Patients found to have hyperplastic lesions on index colonoscopy were compared with those who had "clean" index colonoscopies. The two groups were compared for the subsequent diagnosis of adenomatous polyps on follow-up colonoscopies. Those with cancer or adenomas at index colonoscopy or in their history were excluded. We used Cox proportional hazard modeling with subsequent adenoma or cancer diagnosis at follow-up colonoscopy as the outcome, controlling for age and gender.
  
  
  RESULTS
  We identified 42 patients for whom hyperplastic polyps were the only colorectal neoplasms found on the index examination, in contrast to 362 control patients who had a "clean" index examination. In this cohort study, patients found to have only hyperplastic polyps on initial examination had a rate of subsequent adenoma diagnoses (42%) twice that of patients with a clean initial colonoscopy (21%). Mean follow-up time was 4.3 years. The relative rate ratio was 2.0 (95% confidence interval, 1.2-3.4).
  
  
  CONCLUSIONS
  This study suggests that patients found to have hyperplastic polyps on initial colonoscopic examination may have twice the risk of adenomas on follow-up colonoscopy, as compared with those who have clean initial examinations. If this finding is borne out in larger prospective studies, surveillance strategies may need to be modified accordingly.
authors.affiliation: Department of Surgery, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA. eh257@columbia.edu
authors.forename: E H
authors.initials: EH
authors.lastname: Huang
authors.forename: R L
authors.initials: RL
authors.lastname: Whelan
authors.forename: N R
authors.initials: NR
authors.lastname: Gleason
authors.forename: J S
authors.initials: JS
authors.lastname: Maeda
authors.forename: M B
authors.initials: MB
authors.lastname: Terry
authors.forename: S W
authors.initials: SW
authors.lastname: Lee
authors.forename: A I
authors.initials: AI
authors.lastname: Neugut
authors.forename: K A
authors.initials: KA
authors.lastname: Forde
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000453:epidemiology; D000236:Adenoma / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology; D018256:Adenomatous Polyps / Q000175:diagnosis / Q000453:epidemiology; D015331:Cohort Studies; D003111:Colonic Polyps / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology; D003113:Colonoscopy / Q000706:statistics & numerical data*; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology; D016001:Confidence Intervals; D005500:Follow-Up Studies; D006801:Humans; D006965:Hyperplasia; D015994:Incidence; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies