A prospective study of the frequency and the topographical distribution of colon neoplasia in asymptomatic average-risk Chinese adults as determined by colonoscopic screening.
BACKGROUND
The goal of this study was to determine the frequency of colorectal neoplasia in an asymptomatic Taiwanese population and the topographic distribution of lesions relative to age and gender.


METHODS
Colonoscopy was performed in 1846 consecutive asymptomatic adults undergoing a health evaluation in 2003. Neoplastic lesions were considered advanced if they exceeded 10 mm in size, had a villous component, or contained moderately or severely dysplastic tissue or invasive cancer. Lesions at and proximal to the splenic flexure were considered proximal in location; those distal to the splenic flexure were classified as distal in location.


RESULTS
Of 1741 (94.3%) patients (1041 men, 700 women; mean 52.5 years) enrolled, 1708 (98.1%) underwent total colonoscopy. Of these patients, 263 (15.4%) had colorectal neoplasia; 51 (3.0%) had advanced lesions. A total of 331 lesions were detected; 125 (37.8%) were proximal in location. Two thirds of patients with proximal advanced lesions (66.7%, 10/15) had no distal lesion. The proportion of patients with proximal or proximal plus distal lesions increased with age ( p = 0.027).


CONCLUSIONS
Colonoscopy is an effective primary screening modality for colorectal neoplasia in asymptomatic Chinese patients. Many lesions would be missed, especially in the elderly, if only sigmoidoscopy was used for initial screening.
Chiu
Han-Mo
HM
Department of Internal Medicine, Emergency Medicine, National Taiwan University College of Medicine, Taipei, Taiwan.
Wang
Hsiu-Po
HP
Lee
Yi-Chia
YC
Huang
Shih-Pei
SP
Lai
Yo-Ping
YP
Shun
Chia-Tung
CT
Chen
Ming-Fong
MF
Wu
Ming-Shiang
MS
Lin
Jaw-Town
JT
D000328:Adult; D017677:Age Distribution; D000368:Aged; D003110:Colonic Neoplasms / Q000453:epidemiology* / Q000473:pathology*; D003113:Colonoscopy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011446:Prospective Studies; D012004:Rectal Neoplasms / Q000453:epidemiology* / Q000473:pathology*; D017678:Sex Distribution; D013624:Taiwan / Q000453:epidemiology