Fecal Screening Assay for Taiwanese Population
Condition: Advanced Colorectal Neoplasms; Throat Cancer; Esophageal Cancer; Gastric Cancer; Important Lower and Upper Gastrointestinal Tract Lesions
MeSH terms: Colorectal Neoplasms
Study type: Observational

Summary: 
      Fecal occult blood test (FOBT) is a convenient tool for the screening of asymptomatic
      gastrointestinal (GI) bleeding while 「guaiac-based fecal occult test (G-FOBT) 」 is
      increasingly replaced by the use of an 「immunochemical-based test (I-FOBT) 」 that reacts with
      human globin, a protein that is digested by upper GI enzymes and is specific for detecting
      lower GI bleeding. However, in Taiwan, although the incidence of colorectal cancer is rapidly
      increasing, Helicobacter pylori-related upper GI pathologies remain highly prevalent, which
      may imply that mass screening solely based on I-FOBT could be insufficient as significant
      upper GI pathologies can be missed. Since I-FOBT dose not predict upper GI pathologies, the
      adjuncts of G-FOBT and H. pylori stool-antigen test (HpSA) may be a potential candidate to
      realize a pan-detecting assay based on stool samples in a population in which both lower and
      upper GI lesions are equally prevalent.
    

Detailed description: 
      Background and objective: Fecal occult blood test (FOBT) is a convenient tool for the
      screening of asymptomatic gastrointestinal (GI) bleeding while 「guaiac-based fecal occult
      test (G-FOBT) 」 is increasingly replaced by the use of an 「immunochemical-based test (I-FOBT)
      」 that reacts with human globin, a protein that is digested by upper GI enzymes and is
      specific for detecting lower GI bleeding. However, in Taiwan, although the incidence of
      colorectal cancer is rapidly increasing, Helicobacter pylori-related upper GI pathologies
      remain highly prevalent, which may imply that mass screening solely based on I-FOBT could be
      insufficient as significant upper GI pathologies can be missed. Since I-FOBT dose not predict
      upper GI pathologies, the adjuncts of G-FOBT and H. pylori stool-antigen test (HpSA) may be a
      potential candidate to realize a pan-detecting assay based on stool samples in a population
      in which both lower and upper GI lesions are equally prevalent.

      Patients: Our study will enroll consecutive subjects participating in the health check-up at
      National Taiwan University Hospital (Health Management Center), who will undergo I-FOBT,
      G-FOBT, HpSA, colonoscopy and EGD. The diagnostic values of three fecal testing, alone or in
      combination, will be respectively evaluated. knowing that subjects who were detected with
      gastrointestinal tract cancers might be small based on one screening setting, we also
      recruited patients who were detected with gastrointestinal tract cancers at other screening
      sites and were referred to the National Taiwan University Hospital for confirmatory diagnosis
      and treatment. They were also requested to complete the three fecal tests as well as the
      bidirectional endoscopies; however, it should be noted that, in this group of patients, those
      who completed only one of the bidirectional endoscopies were still eligible.

      Our primary hypothesis was to test whether a guaiac-based test combined with an
      immunochemical test could help differentiate occult bleeding in the upper gastrointestinal
      tract from that in the lower gastrointestinal tract. As such a hypothesis would not be held,
      we also evaluated an alternative choice based on Helicobacter pylori stool antigen test to
      catching the upper gastrointestinal tract lesions.
    

Intervention name(s): Fecal immunochemical test, guaiac fecal occult-blood test, and Helicobacter pylori stool antigen test
Intervention type(s): Other
Other intervention name(s): Fecal immunochemical test: OC-SENSOR; Eiken Chemical Co., Ltd, Tokyo, Japan; Guaiac fecal occult-blood test: Hemoccult SENSA Single Slides, Beckman Coulter Inc., USA; Helicobacter pylori stool antigen test: Easy One Step Test, Firstep Bioresearch, Inc., Taiwan
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Our study will enroll consecutive subjects participating in the health check-up at National
        Taiwan University Hospital (Health Management Center), who will undergo a standard
        protocol, including I-FOBT, G-FOBT, HpSA, face-to-face interviews, blood chemistries,
        colonoscopy and EGD. Prior to the examination, a self-administered questionnaire will be
        used to collect information on participants' demographics, social habits, clinical
        symptoms, and medical/medication histories. To ensure that our study population was
        asymptomatic and the bleeders were occult, we excluded those who had overt GI symptoms and
        overt GI bleeding from analyses. During the same period, patients with screening detected
        GI tract cancers from other screening sites, such as throat cancer, esophageal cancer,
        gastric cancer, and colorectal cancers, will also be invited to participated in the study.
        This enrollment was based on insufficient GI cancer case number in the interim analyses
        based on a single screening site.
      
Keywords: Fecal immunochemical test; Guaiac fecal occult blood test; Helicobacter pylori stool antigen test; Mass screening; Bidirectional endoscopy