Screening colonoscopy in asymptomatic average-risk Koreans: analysis in relation to age and sex

Although the incidence of colorectal cancer is rising in Asian countries, there are no guidelines for its screening in this region due in part to the lack of epidemiological data regarding colorectal neoplasms. This study aimed to evaluate the prevalence of colorectal neoplasms in average-risk Koreans and to assess the effectiveness of screening colonoscopy in Korea.

The prevalence of colorectal neoplasms was assessed by primary screening colonoscopy in 5,086 consecutive asymptomatic adults (males 70.5%; age 20-84 years) with no risk factors for colorectal cancer.

The overall prevalence of colorectal neoplasms in the 5,086 subjects was 21.9% and this increased linearly with age. Among the 2,435 subjects aged >or=50 years (males 66.7%; mean age 57.7 years), the prevalence of all colorectal neoplasms was 30.2% (males 35.9% vs females 18.7%; P < 0.001), while advanced neoplasms accounted for only 4.1% (males 5.1% vs females 2.0%; P < 0.001). The prevalence of advanced neoplasms in Korean men of a specific age group was similar to that of Korean women in the 10-years older age group. Also, Koreans in a specific age group showed a prevalence of advanced neoplasms similar to that of Westerners in the 10-years younger age group.

Colonoscopy is a useful modality for colorectal cancer screening in Korea, as established in Western countries. However, the screening colonoscopy may begin at an older age for Koreans than for Westerners. Similarly, the optimal starting age for screening in Korean women may be higher than that in men by 10 years.