Accuracy of faecal occult blood test andHelicobacter pyloristool antigen test for detection of upper gastrointestinal lesions

Abstract

ObjectiveHighly sensitive guaiac-based faecal occult blood (Hemoccult SENSA) and Helicobacter pylori stool antigen testing might help detect upper gastrointestinal lesions when appended to a colorectal cancer screening programme with faecal immunochemical testing. We evaluated the diagnostic accuracies of two stool tests in detecting upper gastrointestinal lesions.DesignCross-sectional design.SettingHospital-based and community-based screening settings.ParticipantsA hospital-based deviation cohort of 3172 participants to evaluate test performance and a community-based validation cohort of 3621 to verify the findings.InterventionsThree types of stool tests with bidirectional endoscopy as the reference standard.OutcomesSensitivity, specificity and positive and negative likelihood ratios.ResultsFor detecting upper gastrointestinal lesions in cases with negative immunochemical tests, the sensitivity, specificity, and positive and negative likelihood ratios of the guaiac-based and H pylori antigen tests were 16.3% (95% CI 13.3% to 19.8%), 90.1% (88.9% to 91.2%), 1.64 (1.31 to 2.07), and 0.93 (0.89 to 0.97), respectively, and 52.5% (48.1% to 56.9%), 80.6% (79.0% to 82.1%), 2.71 (2.41 to 3.04) and 0.59 (0.54 to 0.65), respectively. For detecting upper gastrointestinal lesions in cases with normal colonoscopy, the results of the guaiac-based and H pylori antigen tests were 17.9% (14.8% to 21.5%), 90.1% (88.9% to 91.2%), 1.81 (1.45 to 2.26) and 0.91 (0.87 to 0.95), respectively, and 53.1% (48.6% to 57.4%), 80.7% (79.1% to 82.2%), 2.75 (2.45 to 3.08) and 0.58 (0.53 to 0.64), respectively. Within the community, positive predictive values of the immunochemical and H pylori antigen tests were 36.0% (26.0% to 46.0%) and 31.9% (28.3% to 35.5%), respectively, for detecting lower and upper gastrointestinal lesions, which were similar to expected values.ConclusionsThe H pylori stool antigen test is more accurate than the guaiac-based test in the screening of upper gastrointestinal lesions in a population with high prevalence of H pylori infection and upper gastrointestinal lesions. It is applicable to add the H pylori antigen test to the immunochemical test for pan detection.Trial registrationNCT01341197 (ClinicalTrial.gov).

Diagnosis of Helicobacter pylori Infection

“…Furthermore, H. pylori SAT (easy One‐Step Test, Firstep Bioresearch, Taiwan) was added to the fecal occult blood tests used for colorectal cancer screening, in order to detect upper gastrointestinal (GI) lesions, mostly due to H. pylori , in a program in Taiwan. Of 31,721 participants, the prevalence of upper GI lesions was higher in those with a positive H. pylori SAT (34.6%) than in those with a positive guaiac‐based test (24.7%) .…”

Screening and treating Helicobacter pylori infection for gastric cancer prevention on the population level

“…This established delivery system could be readily adapted into a two‐in‐one test: a stool sample test panel for colorectal cancer (with fecal immunochemical test [FIT]) and gastric cancer prevention (with H. pylori stool antigen test [HPSA]). In fact, such a pilot program was launched in Changhua County in 2012 . Those who tested positive for the FIT and HPSA were referred for colonoscopic confirmation and antibiotic treatment, respectively.…”

Implementation of gastric cancer screening – The global experience

“…As an extension of this work and based on the recently published experience of a community-based validation study [66], two additional counties in Taiwan (Changhua County and Yi-Lan County) have implemented simultaneous colorectal and GC screening programs using 2 faecal samples, after feasibility studies. These activities are funded by the two local governments, and the decision on whether this approach could become a nationwide screening program is still uncertain.…”