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

Background: Colorectal cancer (CRC) is one of the prime causes of mortality around the globe, with asignificantly rising incidence in the Middle East region in recent decades. Since detection of CRC in the earlystages is an important issue, and also since to date there are no comprehensive epidemiologic studies depictingthe Middle East region with special attention to the average risk group, further investigation is of significantnecessity in this regard. Aim: Our aim was to investigate the prevalence of preneoplastic and neoplastic lesionsof the colon in an average risk population. Materials and
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, wereenrolled. They underwent colonoscopy screening and all polypoid lesions were removed and examined by anexpert 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 ± 9.59and 51.6% were male. The overall polyp detection rate was 199/1208 (16.5 %), 26 subjects having non-neoplasticpolyps, including hyperplastic lesions, and 173/1208 (14.3%) having neoplastic polyps, of which 26 (2.15%) wereadvanced 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 detectedin the distal colon, but a quarter of advanced adenomas were found in the proximal colon; advance age andmale gender was associated with the presence of adenoma.
Conclusions: It seems that CRC screening amongaverage-risk population might be recommended in countries such as Iran. However, sigmioidoscopy alone wouldmiss many colorectal adenomas. Furthermore, the 50-59 age group could be considered as an appropriate targetpopulation for this purpose in Iran.