Difference in Performance of Fecal Immunochemical Tests With the Same Hemoglobin Cutoff Concentration in a Nationwide Colorectal Cancer Screening Program

• Published in: Gastroenterology (New York, N.Y. 1943) Vol. 147; no. 6; pp. 1317 - 1326
• Main Authors: Chiang, Tsung-Hsien, Chuang, Shu-Lin, Chen, Sam Li-Sheng, Chiu, Han-Mo, Yen, Amy Ming-Fang, Chiu, Sherry Yueh-Hsia, Fann, Jean Ching-Yuan, Chou, Chu-Kuang, Lee, Yi-Chia, Wu, Ming-Shiang, Chen, Hsiu-Hsi
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.2014
• Subjects: Adenoma - diagnosis; Adenoma - epidemiology; Aged; Colorectal Cancer; Colorectal Neoplasms - diagnosis; Colorectal Neoplasms - mortality; Feces - chemistry; Female; Gastroenterology and Hepatology; Hemoglobins - analysis; Humans; Immunochemistry - methods; Immunochemistry - statistics & numerical data; Incidence; Interval Cancer; Japan - epidemiology; Male; Mass Screening - methods; Mass Screening - statistics & numerical data; Middle Aged; Models, Biological; Occult Blood; Population Screening; Predictive Value of Tests; Referral and Consultation - statistics & numerical data; Risk Factors; Screening Test Sensitivity; Sensitivity and Specificity; Japan; Population Screening; FIT; RR; Screening Test Sensitivity; Interval Cancer; ISO; CRC; CI; Colorectal Cancer; SR; International Organization for Standardization; screening rate; fecal immunochemical test; relative risk; confidence interval
• ISSN: 0016-5085; 1528-0012; 1528-0012
• DOI: 10.1053/j.gastro.2014.08.043

We investigated whether 2 quantitative fecal immunochemical tests (FITs) with the same cutoff concentration of fecal hemoglobin perform equivalently in identifying patients with colorectal cancer (CRC). A total of 956,005 Taiwanese subjects, 50 to 69 years old, participated in a nationwide CRC screening program to compare results from 2 FITs; 78% were tested using the OC-Sensor (n = 747,076; Eiken Chemical Co, Tokyo, Japan) and 22% were tested using the HM-Jack (n = 208,929; Kyowa Medex Co Ltd, Tokyo, Japan), from 2004 through 2009. The cutoff concentration for a positive finding was 20 μg hemoglobin/g feces, based on a standardized reporting unit system. The tests were compared using short-term and long-term indicators of performance. The OC-Sensor test detected CRC in 0.21% of patients, with a positive predictive value of 6.8%. The HM-Jack test detected CRC in 0.17% of patients, with a positive predictive value of 5.2%. The rate of interval cancer rate was 30.7/100,000 person-years among subjects receiving the OC-Sensor test and 40.6/100,000 person-years among those receiving the HM-Jack test; there was significant difference in test sensitivity (80% vs 68%, P = .005) that was related to the detectability of proximal CRC. After adjusting for differences in city/county, age, sex, ambient temperature, and colonoscopy quality, significant differences were observed between the tests in the positive predictive value for cancer detection (adjusted relative risk = 1.29; 95% confidence interval, 1.14–1.46) and the rates of interval cancer (0.75; 95% confidence interval, 0.62–0.92). Although each test was estimated to reduce CRC mortality by approximately 10%, no significant difference in mortality was observed when the 2 groups were compared. Different brands of quantitative FITs, even with the same cutoff hemoglobin concentration, perform differently in mass screening. Population-level data should be gathered to verify the credibility of quantitative laboratory findings.