title: Risk Factors Such as Male Sex, Smoking, Metabolic Syndrome, Obesity, and Fatty Liver Do Not Justify Screening Colonoscopies Before Age 45.
abstract: BACKGROUND
  Recently, many studies have reported that male sex, smoking, fatty liver, metabolic syndrome (MetS), and obesity are risk factors for colorectal neoplasia (CRN). However, current guidelines recommend that persons at average risk of colorectal cancer begin screening colonoscopy at age 50 years without consideration of those risk factors.
  
  
  OBJECTIVE
  To investigate an appropriate time to start screening colonoscopies in persons with risk factors for CRN.
  
  
  METHODS
  We performed a cross-sectional study on 27,894 Korean aged ≥30 years who underwent a first colonoscopy as part of a health screening program. To compare the efficacy of colonoscopic screening for the detection of advanced CRN among age groups with risk factors, we calculated the number needed to screen (NNS) to identify 1 patient with advanced CRN.
  
  
  RESULTS
  The NNS for those 30-39 years old with all risk factors, male gender, smoking (≥10 pack-years), MetS, obesity, and fatty liver, was higher than that for ≥50-year-old female subjects (55.4 vs. 26.4). The NNS for those 40-44 years old with all risk factors (37.1) was also higher than that for ≥50-year-old female subjects. However, the NNS for those 45-49 years old with risk factors (16.9-22.9) was lower than that for ≥50-year-old women.
  
  
  CONCLUSIONS
  The efficacy of colonoscopic screening in people 30-44 years old with multiple risk factors is lower than that in ≥50-year-old women. Risk factors such as male sex, smoking, MetS, obesity, and fatty liver do not justify starting screening colonoscopies before age 45.
authors.affiliation: Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University, School of Medicine, 108, Pyung-Dong, Jongro-Ku, Seoul, 110-746, Korea.
authors.forename: Yoon Suk
authors.initials: YS
authors.lastname: Jung
authors.affiliation: Center for Cohort Studies, Total Healthcare Center, Kangbuk Samsung Hospital, Sungkyunkwan University, School of Medicine, Seoul, Korea.
authors.forename: Kyung Eun
authors.initials: KE
authors.lastname: Yun
authors.affiliation: Center for Cohort Studies, Total Healthcare Center, Kangbuk Samsung Hospital, Sungkyunkwan University, School of Medicine, Seoul, Korea.|Department of Occupational and Environmental Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University, School of Medicine, Seoul, Korea.
authors.forename: Yoosoo
authors.initials: Y
authors.lastname: Chang
authors.affiliation: Center for Cohort Studies, Total Healthcare Center, Kangbuk Samsung Hospital, Sungkyunkwan University, School of Medicine, Seoul, Korea.|Department of Occupational and Environmental Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University, School of Medicine, Seoul, Korea.
authors.forename: Seungho
authors.initials: S
authors.lastname: Ryu
authors.affiliation: Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University, School of Medicine, 108, Pyung-Dong, Jongro-Ku, Seoul, 110-746, Korea. diksmc.park@samsung.com.
authors.forename: Dong Il
authors.initials: DI
authors.lastname: Park
mesh_terms: D000328:Adult; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D005234:Fatty Liver; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000592:standards*; D024821:Metabolic Syndrome; D008875:Middle Aged; D009765:Obesity; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D012907:Smoking
keywords: Colorectal neoplasia; Risk factor; Screening colonoscopy