Feasibility Study of FIT and Colonoscopy Screening Precancerous Lesions and Early Cancer in High-Risk Group with Colorectal Tumors

ZHANG Yanping; FAN Qihua; LIU Yong

doi:10.14033/j.cnki.cfmr.2026.05.029

Abstract：Objective:To explore the feasibility of using FIT(fecal occult blood test by immunoassay)and colonoscopy for screening precancerous lesions and early cancer in high-risk populations of colorectal tumors.Method:A total of 8,156 permanent residents aged 40 to 74 years in the county area from June 2024 to March 2025 were selected for screening.Through questionnaire surveys and immunochemical fecal occult blood tests,the high-risk groups of colorectal cancer were initially screened and evaluated.The high-risk patients underwent colonoscopy screening and histopathological diagnosis.The results were analyzed based on colonoscopy and pathological examinations.Taking the pathological examination results as the gold standard,Kappa consistency analysis was used to compare the application value of FIT and colonoscopy in the early screening of precancerous lesions.Result:Among the 8,156 study population,the proportion of male gender(60.36％)was relatively high,the proportion of those aged 51～60(38.19％)was relatively high,the proportion of those with a junior high school education or below(53.73％)was relatively high,46.95％of the population had a history of smoking,57.53％had a history of drinking alcohol,and 6.41％had a history of previous polyp detection.4.76％had a previous history of chronic colitis.A total of 8,156 people were screened in the entire county area,among which 449 cases(5.51％)were positive for FIT,and 374 cases underwent gastroscopy and colonoscopy.Among the 374 patients who underwent gastroscopy and colonoscopy,45 cases were confirmed positive by histopathology,including 31 cases of advanced colon cancer,12 cases of early colon cancer,1 case of advanced gastric cancer,and 1 case of early gastric cancer.The number of negative cases was 329.Taking histopathological examination as the gold standard,there were 239 positive patients diagnosed by gastroscopy and colonoscopy,among which 41 were true positive patients,198 were false positive patients and 4 were false negative patients.The sensitivity of gastroscopy and colonoscopy was 91.11％,the specificity was 39.82％,the accuracy was 45.99％,the positive predictive value was 17.15％,the negative predictive value was 97.04％,and the Kappa value was 0.108.Conclusion:The combined examination of FIT and endoscopy can better improve the sensitivity and specificity of early screening for high-risk populations of colorectal tumors,and enhance the clinical screening ability for precancerous lesions and early cancer.