Uptake and detection rate of colorectal cancer screening with colonoscopy in China: A population-based, prospective cohort study.

BACKGROUND: Colorectal cancer is the leading cause of cancer-related death worldwide. Colonoscopy is widely used as a screening test for detecting colorectal cancer in many countries. However, there is little evidence regarding the uptake and diagnostic yields of colonoscopy in population-based screening programs in countries with limited medical resources.

OBJECTIVE: We reported the uptake of colonoscopy and the detection of colorectal lesions and explored related factors based on a colorectal cancer screening program in China.

DESIGN: Individuals aged 45-74 years who were asymptomatic for colorectal cancer and had no history of colorectal cancer were recruited. An established risk score system was used to identify individuals at high risk for colorectal cancer, and they were subsequently recommended for colonoscopy.

SETTING: A population-based, prospective cohort study was implemented in 169 communities, 14 districts of Chongqing, Southwest China.

PARTICIPANTS: A total of 288,150 eligible participants were recruited from November 2013 to June 2021, and 41,315 participants were identified to be at high risk of colorectal cancer.

METHODS: Generalized linear mixed model was used to explore the individual and community structural characteristics associated with uptake of colonoscopy. Additionally, the detection rate of colorectal lesions under colonoscopy screening was also reported, and their associated factors were explored.

RESULTS: 7859 subjects underwent colonoscopy, with an uptake rate of 19.02 % (95 % CI 18.64 %-19.40 %). Lower uptake rates were associated with older age, lower education, more physical activity, and structural characteristics, including residing in developing areas (OR 0.73, 95 % CI 0.69-0.78), residing more than 5 km from screening hospital (5-10 km: OR 0.85, 95 % CI 0.79-0.91; >10 km: OR 0.85, 95 % CI 0.80-0.91), and not being exposed to social media publicity (OR 0.63, 95 % CI 0.53-0.75). Overall, 8 colorectal cancers (0.10 %), 423 advanced adenomas (5.38 %), 820 nonadvanced adenomas (10.43 %), and 684 hyperplastic polyps (8.70 %) were detected, with an adenoma detection rate of 15.92 %. Several factors, including older age, male, current smoking and a family history of colorectal cancer, were positively related to colorectal neoplasms.

CONCLUSIONS: The uptake of colonoscopy for colorectal cancer screening was not optimal among a socioeconomically diverse high-risk population. The screening strategy should attempt to ensure equitable access to screening according to regional characteristics, and enhance the uptake of colonoscopy by recommended multifaceted interventions, which focus on individuals with poor compliance, select a closer screening hospital, and strengthen social media publicity at the structural level.