Korean colonoscopy screening pilot study (K-cospi) for screening colorectal cancer: study protocol for the multicenter, community-based clinical trial
Authors: Park Bomi , Jun Jae Kwan , Kim Byung Chang , Choi Kui Son , Suh Mina ,   The Expert Advisory Committee, Kim Young Sun , Kim Tae Il , Park Eun-Cheol , Sohn Dae Kyung , Sohn JinHee , Youk Eui Gon , Chang Woong Ki , Jang Byung Ik , Jeong Seung-Yong , Cha Jae Myung , Han Jae Yong ,   The Monitoring Committee, Kim Byung Chang , Kim Hyun Soo , Shin Aesun , Jun Jae Kwan , Choi Nam-Kyong ,   Center for Korean Colonoscopy Screening Pilot Study, Suh Mina , Kim Bun , Myung Seung-Kwon , Park Bomi , Lee Ji Young , Choi Kui Son , Han Kyung Su ,   The Research Team on the Protocol Development of Pilot study, Jeong Seung-Yong , Lim Jong-Phil , Shin Aesun , Park Ji Won , Sohn Dae Kyung , Kim Byung Chang , Suh Mina , Kim Yeol , Choi Sunho , Lee Kyeongmin , Seo Haejoo 
Published: January 2021

Abstract
Background
The Korean National Cancer Screening Program has been providing annual fecal immunochemical test for colorectal cancer (CRC) to adults aged 50 years and older since 2004. The Korean Colonoscopy Screening Pilot Study was developed to evaluate the effectiveness of colonoscopy screening for CRC incidence and mortality, screening-related complications, and acceptability of colonoscopy as a primary modality for the national CRC screening program.

Methods
This study and its protocols have been approved by the Korean Public Institutional Review Board and the National Cancer Center Institutional Review Board. We obtain written informed consent from all participants. The target population is males and females aged 50–74 years living within the pilot sites. A total of 26,640 participants will be recruited for colonoscopy screening. Subjects who have been diagnosed with CRC, who are currently undergoing treatment for CRC, or who have undergone colonoscopy screening within the past 5 years are not allowed to participate. All participants need to complete baseline questionnaires. This pilot study is currently conducted by 104 endoscopists from 57 national cancer screening institutions (42 primary, 10 secondary, and 5 tertiary institutions) located in Goyang-si, Gimpo-si, and Paju-si. The number of endoscopists, medical institutions, and districts participating in the pilot study will be expanded, if necessary. Participating endoscopists at each medical institution perform colonoscopy and report the colonoscopy results to a centralized electronic case report system. We conduct a telephone survey after 7 days and 4 weeks post-colonoscopy to assess for procedure-related complications and satisfaction of the participants. In case of abnormal findings from colonoscopy screening, we track the results from follow-up diagnostic tests. Data from this pilot study will be linked to the diagnostic workup results, the Korean Cancer Registry, and death certificate data for analysis of the performance, long-term effects, and cost-effectiveness of colonoscopy.

Discussion
The results will provide critical information to determine whether the introduction of colonoscopy as the primary modality of the Korean National Cancer Screening Program would be acceptable and feasible.
Trial registration Korean Clinical Research Information Service registry, KCT0004142. Registered on 15 July 2019, http://cris.nih.go.kr/cris/en/search/search_result_st01.jsp?seq=16227