Early detection of gastric cancer and its precursor conditions by endoscopic screening

Although the incidence of gastric cancer is decreasing across the globe,
including Europe, the burden of the disease is still substantial and will not
disappear in the foreseeable future unless effective measures of prevention are
implemented. A key issue is the lack of established programs for early
detection of gastric cancer and its precursor conditions in Western countries.
Thus, gastric cancer is usually diagnosed at an advanced stage when patients
already have symptoms. This results in dismal prognosis and poor survival
rates, emphasizing the necessity for innovative screening strategies. Recent
studies have shown that upper gastro-intestinal lesions are significantly
prevalent in patients with a positive fecal occult blood test, suggesting that
upper endoscopies in patients that need a colonoscopy could be a promising
strategy for gastric cancer screening. However, additional prospective data are
required to confirm these results.

The primary objective of the current protocol is the diagnostic value of a
gastroscopy to detect gastric (pre)-neoplastic conditions in patients who need
a colonoscopy as part of their clinical follow-up either after a positive
screening test for colon cancer (FIT) or as part of polyp surveillance at
Erasmus MC.
The secondary objectives include: i) The prevalence of other upper
gastrointestinal conditions in the study population ii) The extra value of
endoscopy to serology screening among other approaches. iii) The endoscopist*s
performance to detect relevant gastric lesions, as well as oesophageal or
duodenal conditions, and iv) Safety of the procedure and the participants*
satisfaction, including also reasons not to participate.

This study is designed as a single center investigator initiated study in the
Netherlands. This study is part of a larger multinational multicentre study
which is funded through the Horizon Europe project TOGAS. The study will make
use of prospective data collected in the specific context of this study.
Furthermore biomaterial will be collected (e.g. blood, and biopsies).

Patients will be asked to undergo an additional gastroscopy during their
standard of care diagnostic endoscopy during which five biopsies will be taken.
In addition, a blood sample (9 ml) will be taken at the day of endoscopy. In
addition they will complete 1 questionnaire at the day of the endoscopies.

Patients will undergo an additional gastroscopy with Sydney protocol biopsies
(five in total) taken in combination with their scheduled colonoscopy. Upper
endoscopy is considered to be a safe procedure. the risks of a complication
related to the gastroscopy are low (<0,10%), and mostly due to the sedation
provided. However, all patients in this study will already undergo a
colonoscopy with the same sedation, so additional sedation associated risks
will not be applicable. Besides, although upper endoscopy is associated with
distress before and discomfort during the procedure, most patients do not
experience it as painful, and it is reported to cause only a few symptoms
afterward.
In addition to the gastroscopy, patients will undergo additional blood sampling
using an existing cannula (9 ml), and they will be asked to fill in a feedback
form at the day of the endoscopy. These additional procedures do not pose a
significant risk or burden. There is a benefit for participants who test
positive for H. Pylori infection based on the pathology report of the upper
endoscopy. They will be offered eradication therapy with subsequent
confirmation of treatment success. Benefit is also envisioned for participants
with high-risk precancerous lesions based on the pathology report. They will be
advised to undergo regular endoscopic surveillance as per international
guidelines or direct treatment.