Randomized controlled trial comparing the costs of gastric cancer screening systems between serological risk-based upper gastrointestinal endoscopy and the existing barium photofluorography: gastric cancer screening labeled by serum examination in place of aged gastric cancer organized screening systems (GALAPAGOS study).

Background: Although the risk of gastric cancer can be stratified according to Helicobacter pylori (H. pylori) IgG antibody titer and pepsinogen levels (ABC classification), a population-based gastric cancer screening system combining serological tests and endoscopy has not been introduced. This study aimed to compare the total testing cost per participant between the ABC classification method and the existing protocol.

Methods: Using the minimization method with sex and age as allocation factors, 1206 participants were randomly assigned to the following two methods for a 5-year intervention: barium photofluorography as primary examination followed by detailed examination with upper gastrointestinal endoscopy (Ba-Endo) and risk-based upper gastrointestinal endoscopy by ABC classification (ABC-Endo). The primary endpoint was the total testing cost per participant over a 5-year period. The secondary endpoint was the expense required to detect one gastric cancer.

Results: The total testing cost per participant was 39,711 yen in Ba-Endo (604 participants) and 45,227 yen in ABC-Endo (602 participants), with the latter being significantly higher (p < 0.001). During the intervention period, gastric cancer was found in 11 and eight participants in Ba-Endo and ABC-Endo, respectively. The expenses required to detect one gastric cancer were 2,240,931 yen in Ba-Endo and 3,486,662 yen in ABC-Endo.

Conclusions: The testing cost per participant turned out to be higher in the ABC-Endo group than in the Ba-Endo group. This superiority trial, based on the hypothesis that the cost of testing is lower for ABC-Endo than for Ba-Endo, was rejected.