Eradicating Helicobacter pylori via 13C-urea breath screening to prevent gastric cancer in indigenous communities: a population-based study and development of a family index-case method

Abstract

Objective: Screening and eradication of Helicobacter pylori help reduce disparities in the incidence of gastric cancer. We aimed to evaluate its acceptability and feasibility in the indigenous communities and develop a family index-case method to roll out this programme.

Design: We enrolled residents aged 20-60 years from Taiwanese indigenous communities to receive a course of test, treat, retest and re-treat initial treatment failures with the ¹³C-urea breath tests and four-drug antibiotic treatments. We also invited the family members of a participant (constituting an index case) to join the programme and evaluated whether the infection rate would be higher in the positive index cases.

Results: Between 24 September 2018 and 31 December 2021, 15 057 participants (8852 indigenous and 6205 non-indigenous) were enrolled, with a participation rate of 80.0% (15 057 of 18 821 invitees). The positivity rate was 44.1% (95% CI 43.3% to 44.9%). In the proof-of-concept study with 72 indigenous families (258 participants), family members of a positive index case had 1.98 times (95% CI 1.03 to 3.80) higher prevalence of H. pylori than those of a negative index case. The results were replicated in the mass screening setting (1.95 times, 95% CI 1.61 to 2.36) when 1115 indigenous and 555 non-indigenous families were included (4157 participants). Of the 6643 testing positive, 5493 (82.6%) received treatment. According to intention-to-treat and per-protocol analyses, the eradication rates were 91.7% (89.1% to 94.3%) and 92.1% (89.2% to 95.0%), respectively, after one to two courses of treatment. The rate of adverse effects leading to treatment discontinuation was low at 1.2% (0.9% to 1.5%).

Conclusion: A high participation rate, a high eradication rate of H. pylori and an efficient rollout method indicate that a primary prevention strategy is acceptable and feasible in indigenous communities.

Trial registration number: NCT03900910.

Keywords: cancer prevention; gastric cancer; helicobacter pylori; helicobacter therapy; screening.

Figure 1. Prevalence rates of Helicobacter pylori infection by the age ranges (20–29, 30–39, 40–49 and ≥50 years), stratified by indigenous status.

Figure 2. Risk factors associated with 6643 positive results of the ¹³C-urea breath tests among 15 057 participants in the indigenous communities. The multivariable model, adjusted for all variables, is shown in the forest plot. An OR greater than 1.0 (dotted line) indicates an increased risk of Helicobacter pylori (H. pylori) infection.

Figure 3. The infection–pedigree relationships of two indigenous families in the proof-of-concept study to demonstrate the rationale of the family index-case method. The prevalence rate of Helicobacter pylori infection in the family members of the positive index case will be about twofold higher than that in the family members of the negative index case due to intrafamilial transmission. The two families are the numbers 48 and 59 shown in the online supplemental table 2A.

Figure 4. Risk factors associated with the 1150 non-referrals among 6643 participants who tested positive for Helicobacter pylori (H. pylori) infection. The multivariable model, adjusted for all variables, is shown in the forest plot. An OR greater than 1.0 (dotted line) indicates an increased risk of non-referral to treatment.

Figure 5. Risk factors associated with the 1024 treatment failures among 5493 subjects who received the first-line treatment for Helicobacter pylori (H. pylori) infection, according to the intention-to-treat analyses. The multivariable model, adjusted for all variables, is shown in the forest plot. An OR greater than 1.0 (dotted line) indicates an increased risk of treatment failure.