Trial Information

Screening for Stomach Diseases and Colorectal Neoplasms With the Fecal Testing: a Population-based Randomized Study

Growing body of evidences have shown that fecal immunochemical test (FIT) outperform guaiac
fecal occult blood test (gFOBT) in terms of sensitivity, neoplasm detection rate and public
participation. Though direct outcome evidence is still lacking for FIT, it is anticipated to
have higher colorectal cancer (CRC) mortality and incidence reduction compared with gFOBT.
In Taiwan, nation-wide CRC screening program has been launched since the year of 2004 ,which
provides biennial FIT screening for adults aged 50 to 69 years. Currently available data
from the Bureau of Health Promotion has shown a significant stage-shift effect, an early
indicator of screening effectiveness, by this screening program.

Nevertheless, the aforementioned advantages of FIT, missed neoplasms and interval cancer
still exists under the current one-day stool sampling method with biennial screening
interval, which might affect the effectiveness of overall screening program. Increase the
number of stool samples or shortening of screening interval may be helpful for early
detection of clinically significant neoplasms but it remains unclear whether such an
approach may lower the screenee compliance or public participation. Moreover, its impact on
the demand of confirmatory colonoscopy and cost-effectiveness of the whole screening program
is still largely unknown and need to be further investigated.

In this study, we firstly aim to randomly allocate screening attendee to one of the
following four arms: one-day sampling with annual screening, one-day sampling with biennial
screening, two-day sampling with annual screening, and two-day sampling with biennial
screening. Participation rate, positive rates of FIT, detection rate for neoplasms, positive
predictive value, and long-term outcome including cancer incidence and mortality will be
calculated and compared among four groups.

Secondly, in the Taiwanese population, which is a typical presentation of Asian populations,
although the incidence of colorectal cancer is rapidly increasing, Helicobacter
pylori-related upper gastrointestinal pathologies remain highly prevalent, which may imply
that mass screening solely based on FIT could be insufficient as significant upper GI
pathologies can be missed. Since the FIT does not predict upper GI pathologies, the adjunct
of an「Helicobacter 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. Therefore, in the present study, we will also
evaluate the value of simultaneous FIT and HpSA test in the community-based mass screening.

Thirdly, the cost-effectiveness analysis will be also conducted using previously established
Markov model of CRC natural history and stomach diseases (such as dyspepsia, peptic ulcer
disease, and gastric cancer) using the results ascertained from this trial.