Evaluation of quantitative stool occult blood test in opportunistic screening for colorectal cancer / 中华健康管理学杂志

ABSTRACT

Objective:To evaluate the efficacy of quantitative fecal immunochemical test (fecal immunochemical test, FIT) in the screening of colorectal cancer and precancerous lesions.Methods:47 243 patients who underwent quantitative FIT screening for colorectal cancer in the Health Management Department of Shenzhen People′s Hospital from January 2019 to October 2020 were enrolled as subjects. Colonoscopy was recommended for patients with positive quantitative FIT. A follow-up was done after one year to compare the results of the quantitative FIT positive group and the negative group after colonoscopy. Data were adjusted by propensity score matching method and a receiver operating characteristic curve ( ROC) was established to evaluate the diagnostic effect of quantitative FIT combined with colonoscopy on colorectal cancer and precancerous lesions. Results:A hemoglobin concentration>100 μg/L was set as a positive threshold. There were 2 472 positive cases of quantitative FIT, and the positive rate was 5.23%. After one-year follow-up, 284 patients had completed colonoscopy; the colonoscopy compliance was 11.49%. Of the negative population, 1 493 patients selected colonoscopy within one year. Compared with the results of gold standard colonoscopy, the sensitivity and specificity of quantitative FIT for screening for advanced adenoma and cancer were 26.53% and 86.54%, respectively. The sensitivity for colorectal cancer screening was 94.44% and screening for advanced adenoma was 22.77%. After propensity score matching, there were 256 FIT positive patients and 705 FIT negative patients. Colorectal cancer was the outcome variable, while FIT combined with colonoscopy, age combined with colonoscopy, and FIT combined with age combined with colonoscopy were the diagnostic indicators. The areas under the curve were 0.841(95% CI0.778-0.904), 0.677(95% CI 0.535-0.820), and 0.882(95% CI0.807-0.958), respectively. Conclusion:Quantitative FIT has a high susceptibility to opportunistic screening for colorectal cancer, and a low sensitivity to advanced adenoma. At the same time, quantitative FIT combined with colonoscopy has a good diagnostic accuracy for colorectal cancer, which is better than the effect of using age as a cut-off point for colonoscopy. Quantitative FIT combined with age and colonoscopy has the best effect on screening for colorectal cancer. Quantitative FIT has a high sensitivity to colorectal cancer and a low sensitivity to advanced adenoma.