Analysis of factors associated with false-positive results and optimal positivity thresholds of quantitative fecal immunochemical test in colorectal cancer screening
10.3760/cma.j.cn112150-20250119-00058
- VernacularTitle:定量粪便免疫化学试验在结直肠癌筛查中的假阳性相关因素及最佳阈值分析
- Author:
Yi ZHOU
1
;
Weimiao WU
;
Chen ZHU
;
Tingting PAN
;
Jinjin HE
;
Lüe HONG
;
Bin LIU
;
Le WANG
;
Lingbin DU
Author Information
1. 浙江中医药大学公共卫生学院，杭州 310053
- Publication Type:Journal Article
- Keywords:
Colorectal cancer;
Screening;
Quantitative fecal immunochemical test;
Positivity threshold;
False-positive rate
- From:
Chinese Journal of Preventive Medicine
2025;59(10):1691-1702
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To analyze risk factors associated with false-positive results of quantitative fecal immunochemical testing (FIT), evaluate its performance for detecting advanced colorectal neoplasia across different subgroups, and explore the optimal positivity thresholds for each subgroup.Methods:Individuals who participated in the Zhejiang Colorectal Cancer Screening Program in 2020-2021, completed questionnaire-based risk assessment and quantitative FIT for initial screening, and undertook colonoscopy for confirmed diagnosis were included in this study. The information of individuals, including demographic characteristics, lifestyles, history of diseases, and family history of colorectal cancer (CRC), was collected by using questionnaires. The diagnostic outcomes of the individuals were obtained through colonoscopy and pathological examination. Multivariate logistic regression analyses were conducted to identify factors associated with false-positive FIT results. The optimal threshold of FIT was determined based on the receiver operating characteristic (ROC) curve and 10-fold cross-validation. The effectiveness of FIT screening in different subgroups was compared using the unified threshold of 100 ng/ml or optimal positivity thresholds.Results:There were 25 874 individuals included in the analysis, with 14 694 (56.79%) having fecal hemoglobin concentrations ≥100 ng/ml. A total of 3 830 advanced adenoma cases (14.80%) and 362 CRC cases (1.40%) were identified. Age below 60 years old, females, underweight, smoking, drinking, use of nonsteroidal anti-inflammatory drugs, no family history of CRC, no history of intestinal disease, no history of hypertension, and physical inactivity were associated with an elevated risk of false-positive results in FIT ( P<0.05). Compared to the predetermined threshold of 100 ng/ml, the false positive rate (FPR) of quantitative FIT decreased from 52.3% to 37.3% in all individuals, and decreased by more than 20% in females, individuals with normal weight, smokers, and those without a history of intestinal disease when adopting the optimal threshold (all P<0.001). Conclusion:The risk of false-positive results in quantitative FIT varies across different subgroups. Adopting the optimal thresholds could improve the specificity and reduce the FPR of quantitative FIT for CRC screening.
