TOGAS Study: Carrying out a preventive gastroscopy together with a colonoscopy”

Interventions: Group 1: The additional examination (gastroscopy) takes place on the same day as the colonoscopy. In addition to pure endoscopy with image documentation, both tissue samples from the stomach and blood samples are taken. These are not experimental procedures, but rather routine examinations carried out daily.
During the OGD, the endoscopist will carefully inspect the upper GI tract using White Light endoscopy and virtual chromo endoscopy to establish an endoscopic diagnosis. Standardised images will be obtained and stored. For tissue diagnostics, at least two biopsies form the antrum and two from the gastric body will be obtained for histology assessment in concordance with the modified Sydney Classification. One additional biopsy can be taken from the incisura (placed in a separate vial) to facilitate stratification according to the OLGA and OLGIM staging system of gastritis which is directly linked to gastric cancer risk. Additional biopsies from both antrum and body will be taken for H. pylori diagnostics. Following local protocols, this may include rapid urease testing (RUT), PCR or culture.
Additional biopsies will be taken from any visible lesion or area with irregular mucosal surface pattern in endoscopy, suspicious of neoplasia.
On the day of the procedure, a serum sample will be obtained to analyse H. pylori serology and serum levels of Pepsinogen I and II with the latter serving as surrogate parameters for gastric glandular atrophy.
Primary outcome(s): Presence of gastric cancer or gastric precancerous conditions and lesions that require endoscopic surveillance or treatment.
Study Design: Allocation: ; Masking: ; Control: ; Assignment: ; Study design purpose: prevention