Clinical Pearls & Morning Reports
Choi et al. conducted a randomized trial to evaluate whether treatment of Helicobacter pylori infection reduced the risk of gastric cancer in first-degree relatives of patients with gastric cancer. Read the Original Article here.
Q: To what extent does a family history of gastric cancer in a first-degree relative increase the risk of gastric cancer?
A: A family history of gastric cancer in a first-degree relative is associated with double to triple the risk of gastric cancer. Patients with gastric cancer and their relatives share risk factors, including exposure to H. pylori in the environment and genetic features that may affect immune responses to H. pylori infection. Family members of patients with gastric cancer have higher rates of H. pylori infection than persons in the general population, and the precancerous histologic changes in the gastric mucosa are more severe in these persons. However, whether treatment of H. pylori infection can reduce the risk of gastric cancer is still unclear because of a lack of evidence from trials in primary prevention.
Q: Does the American College of Gastroenterology clinical guideline published in 2017 recommend routine testing and treatment of H. pylori infection in relatives of patients with gastric cancer?
A: Despite the uncertainty, regional and global consensus reports recommend treatment of H. pylori infection in the relatives of patients with gastric cancer. In contrast, the American College of Gastroenterology clinical guideline published in 2017 made no recommendation regarding routine testing for and treatment of H. pylori infection in this high-risk group because of insufficient evidence.
A: In this prospective, randomized trial involving first-degree relatives of patients with gastric cancer, the risk of gastric cancer was 55% lower among those who received H. pylori eradication treatment than among those who received placebo, during a median follow-up of 9.2 years. Gastric cancer developed in 10 of 832 participants (1.2%) in the treatment group and in 23 of 844 (2.7%) in the placebo group (P=0.03 by log-rank test). Of the 33 cases of gastric cancer, 28 developed in the 979 participants (2.9%) with persistent infection, and 5 developed in the 608 participants (0.8%) in whom the infection was eradicated (hazard ratio for gastric cancer with eradicated infection as compared with persistent infection, 0.27; 95% CI, 0.10 to 0.70). In this trial, which used a 2-year surveillance interval, the authors detected all gastric cancers at a curable stage (all within stage II).
A: The results of the trial by Choi et al. showed that treatment of H. pylori infection did not result in a lower incidence of gastric adenoma than placebo. This finding is similar to that of a previous trial by Choi et al. involving patients with early gastric cancer; in that trial, the incidence of adenoma was almost equal in the two groups (8.2% in the treatment group and 8.4% in placebo group). The authors state that, together, these trials suggest that the preventative effect of H. pylori treatment is not preceded by a decrease in the incidence of adenoma, and the adenoma–carcinoma sequence is not the pathway activated by H. pylori in the development of gastric cancer.