by Jose Ramon Troche, M.P.H.
Infection with Helicobacter pylori (H. pylori) —a bacterium found in the stomach of about two-thirds of the world’s population—is a major cause of gastric cancer.
The most recent findings from a study of H. pylori treatment in Shandong Province, China, showed long-term benefits from antibiotic treatment for the infection on gastric cancer incidence1, both overall and in specific subgroups. Specifically, Mitchell H. Gail, M.D., Ph.D., and collaborators found that a two-week course of H. pylori treatment given 15 years earlier was associated with lower gastric cancer incidence and mortality in older adults (aged 55 years and older). Incidence, but not mortality, was also statistically significantly reduced in subjects with advanced precancerous lesions. Protective effects (not statistically significant) were seen in patients with H. pylori after treatment.
A previous report from the same trial found that H. pylori treatment was significantly associated with reductions in gastric cancer incidence overall when compared to placebo2. Lowered gastric cancer mortality was also suggested. The present report shows that benefits extended to subgroups with precancerous lesions at baseline and older adults.
The study, known as the Shandong Intervention Trial, was a blinded, randomized placebo-controlled intervention trial started in 1995 by NCI and collaborators at the Beijing Institute for Cancer Research with the purpose of reducing the prevalence of precancerous gastric lesions and gastric cancer in a high-risk Chinese population3. Out of three assigned interventions (antibiotic treatment of H. pylori; daily supplementation with a combination of alpha-tocopherol, vitamin C, and selenium; or daily supplementation with garlic extracts), only H. pylori treatment reduced the prevalence of precancerous gastric lesions in study participants.
1. Li WQ, et al. Effects of Helicobacter pylori treatment on gastric cancer incidence and mortality in subgroups. J Natl Cancer Inst 2014;106(7):pii:dju116
2. Ma JL, et al. Fifteen-year effects of Helicobacter pylori, garlic, and vitamin treatments on gastric cancer incidence and mortality. J Natl Cancer Inst 2012;104(6):488-492
3. You WC, et al. Randomized double-blind factorial trial of three treatments to reduce the prevalence of precancerous gastric lesions. J Natl Cancer Inst 2006;98(14):974-983