Researchers observed that anti-Helicobacter pylori therapy had a long-term beneficial effect among a population at increased risk for gastric cancer, according to findings from a study published in Gastroenterology.
Adult volunteers (N=1219) were recruited from 2 towns in Colombia at high risk for gastric cancer. Participants underwent upper gastrointestinal endoscopy with biopsy and were assessed using the Correa score system (range, 1-6). Individuals who had precancerous lesions (n=800) were randomly assigned in a double-blind trial to receive 2 weeks of anti-H pylori therapy with beta-carotene and/or ascorbic acid supplementation for 6 years. Individuals were assessed by endoscopy at 12, 16, and 20 years after randomization.
At baseline, the mean age of participants was 51±9 years; 46% were men, 97% were positive for H pylori, and 50% were given anti-H pylori therapy. Follow-up data were available for 630 participants at 6 years, for 612 participants at 12 years, for 456 participants at 16 years, and for 356 participants at 20 years. The mean age of those who participated for the entire study was 69±8 years; 45% were men, and 41% were positive for H pylori.
At the 20-year follow-up, a total of 367 instances of a gastric diagnosis were made, including 109 of multifocal atrophic gastritis without intestinal metaplasia, 228 with intestinal metaplasia, 30 with dysplasia, and 1 with gastric cancer.
Individuals who had multifocal atrophic gastritis without intestinal metaplasia at baseline had a higher rate of progression (39%) compared with those with baseline intestinal metaplasia (25%). Of those with baseline intestinal metaplasia, 55% experienced no clinical progress or regression, and those with baseline dysplasia had the highest rate of clinical regression (53%).
H pylori status at prior endoscopy was significantly correlated with clinical progression during the next assessment, in which individuals who were negative for H pylori had a net regression of -0.12 (95% CI, -0.01 to -0.23; P =.03) units in the Correa score and those positive for H pylori had a net progression of 0.28 (95% CI, 0.41-0.14; P <.001) units at 20 years.
A significant interaction between H pylori status and time (P =.036) was observed. Correa scores diverged between infection status groups at 6 years, and individuals negative for H pylori had consistently lower scores compared with those who remained infected with the bacteria.
In total, 12 gastric cancers were diagnosed during the entire study duration in 8 men and 4 women with an average time to gastric cancer of 9.5 (interquartile range [IQR], 3-12) years. Diagnoses occurred at an average age of 64.9±11.1 years. At baseline, those who developed gastric cancer had incomplete intestinal metaplasia (n=7), indefinite dysplasia (n=3), complete intestinal metaplasia (n=1), and low-grade dysplasia (n=1). Of those with gastric cancer, 5 were randomly assigned to the treatment group and 7 to the placebo group.
This study may have been limited by the low retention rate of participants. However, at 20 years, baseline and follow-up distributions for age, gender, and baseline diagnoses were similar.
The study authors concluded that anti-H pylori therapy and clearance of the bacterial infection had a long-term benefit among a population at high risk for gastric cancer.
Piazuelo MB, Bravo LE, Mera RM, et al. The Colombian chemoprevention trial. Twenty-year follow-up of a cohort of patients with gastric precancerous lesions. Gastroenterology. Published online November 18, 2020. doi:10.1053/j.gastro.2020.11.017