title: Prevalence of colorectal polyps in a group of subjects at average-risk of colorectal cancer undergoing colonoscopic screening in Tehran, Iran between 2008 and 2013.
abstract: BACKGROUND
  Colorectal cancer (CRC) is one of the prime causes of mortality around the globe, with a significantly rising incidence in the Middle East region in recent decades. Since detection of CRC in the early stages is an important issue, and also since to date there are no comprehensive epidemiologic studies depicting the Middle East region with special attention to the average risk group, further investigation is of significant necessity in this regard.
  
  
  OBJECTIVE
  Our aim was to investigate the prevalence of preneoplastic and neoplastic lesions of the colon in an average risk population.
  
  
  METHODS
  A total of 1,208 eligible asymptomatic, average- risk adults older than 40 years of age, referred to Firuzgar Hospotal in the years 2008-2012, were enrolled. They underwent colonoscopy screening and all polypoid lesions were removed and examined by an expert gastrointestinal pathologist. The lesions were classified by size, location, numbers and pathologic findings. Size of lesions was measured objectively by endoscopists.
  
  
  RESULTS
  The mean age of participants was 56.5±9.59 and 51.6% were male. The overall polyp detection rate was 199/1208 (16.5 %), 26 subjects having non-neoplastic polyps, including hyperplastic lesions, and 173/1208 (14.3%) having neoplastic polyps, of which 26 (2.15%) were advanced neoplasms .The prevalence of colorectal neoplasia was more common among the 50-59 age group. Advanced adenoma was more frequent among the 60-69 age group. The majority of adenomas were detected in the distal colon, but a quarter of advanced adenomas were found in the proximal colon; advance age and male gender was associated with the presence of adenoma.
  
  
  CONCLUSIONS
  It seems that CRC screening among average-risk population might be recommended in countries such as Iran. However, sigmioidoscopy alone would miss many colorectal adenomas. Furthermore, the 50-59 age group could be considered as an appropriate target population for this purpose in Iran.
authors.affiliation: Gastrointestinal and Liver Disease Research Center, Firoozgar Hospital, Iran University of Medical Sciences, Tehran, Iran E-mail : zamani.f@iums.ac.ir, zamani.farhad@gmail.com.
authors.forename: Masoudreza
authors.initials: M
authors.lastname: Sohrabi
authors.forename: Farhad
authors.initials: F
authors.lastname: Zamani
authors.forename: Hossien
authors.initials: H
authors.lastname: Ajdarkosh
authors.forename: Naser
authors.initials: N
authors.lastname: Rakhshani
authors.forename: Mitra
authors.initials: M
authors.lastname: Ameli
authors.forename: Mehdi
authors.initials: M
authors.lastname: Mohamadnejad
authors.forename: Ali
authors.initials: A
authors.lastname: Kabir
authors.forename: Gholamreza
authors.initials: G
authors.lastname: Hemmasi
authors.forename: Mahmoudreza
authors.initials: M
authors.lastname: Khonsari
authors.forename: Nima
authors.initials: N
authors.lastname: Motamed
mesh_terms: D000236:Adenoma / Q000175:diagnosis / Q000453:epidemiology*; D000328:Adult; D000368:Aged; D003111:Colonic Polyps / Q000175:diagnosis* / Q000453:epidemiology*; D003113:Colonoscopy / Q000379:methods*; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007492:Iran; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D009367:Neoplasm Staging; D015995:Prevalence; D011379:Prognosis; D012307:Risk Factors; D013997:Time Factors