H. pylori Eradication Treatment Reduces the Risk of Gastric Cancer in High Risk Population

SUMMARY: The American Cancer Society estimates that in the US, about 27,600 new cases of stomach cancer will be diagnosed in 2020 and about 11,010 people will die of the disease. It is one of the leading causes of cancer-related deaths in the world. The incidence of gastric cancer in the US has been on the decline and has been attributed to increased use of refrigeration for food storage, making fresh fruits and vegetables more available, and decreased the use of salted and smoked foods. In the United States, Asians and Hispanics have a much higher incidence of gastric cancer.
Several hereditary syndromes such as Hereditary Diffuse Gastric Cancer (HDGC), Lynch syndrome (Hereditary Nonpolyposis Colorectal Cancer) and Familial Adenomatous Polyposis (FAP) have been associated with a predisposition for stomach cancer. HDGC however, is the most common genetic predisposing syndrome for gastric cancer, with germline mutations of the E-cadherin gene (CDH1), detected in 30-50% of diffuse-type gastric cancers. Women with CDH1 mutations are also at an increased risk for breast cancer, and the follow up is similar to BRCA1/BRCA2 mutation carriers. A family history of gastric cancer in a first-degree relative is associated with double to triple the risk of gastric cancer. Gastric cancer overall has a poor prognosis and the 5 year Overall Survival rate is about 25%.
The strongest risk factor for gastric adenocarcinoma is infection with Helicobacter pylori (H.pylori), which is a gram-negative, spiral-shaped microaerophilic bacterium. This bacterial species colonizes the stomach and the overall estimate of H. pylori prevalence in adults is 76% in developing countries and 58% in developed countries. The association between H.pylori and gastric cancer has been shown in observational and case-control studies. In a recently published randomized trial (NEJM 2018;378:1085-1095), treatment of H. pylori infection in patients with early gastric cancer reduced the risk of metachronous gastric cancer by 50%.
It has been unclear whether treatment to eradicate H. pylori can reduce the risk of gastric cancer in individuals with a family history of gastric cancer in first-degree relatives. To address this question, the authors in this single-center, double-blind, placebo-controlled trial, randomly assigned 1838 participants with H. pylori infection and at least one first-degree relative with gastric cancer, in a 1:1 ratio to receive either H.pylori eradication therapy with Amoxicillin 1000 mg, Clarithromycin 500 mg, and Proton-Pump Inhibitor Lansoprazole 30 mg, each taken twice daily for 7 days or placebo. Eligible participants were 40-65 years of age and key exclusion criteria included a history of gastric cancer, peptic ulcer, or other malignancy, and previous eradication therapy for H. pylori. Surveillance endoscopies were performed every 2 years and suspicious lesions were biopsied for gastric cancer. A closeout endoscopy, with H. pylori evaluation, was performed at the end of the trial period. The Primary outcome was development of gastric cancer. A prespecified Secondary outcome was development of gastric cancer according to H. pylori eradication status, assessed during the follow-up period after receipt of H. pylori treatment or placebo. A total of 1676 participants (832 in the treatment group and 844 in the placebo group) were included in the primary outcome analysis.
During a median follow up of 9.2 years, the risk of gastric cancer was 55% lower among those who received H. pylori eradication treatment than among those who received placebo (HR=0.45; P=0.03). Among those who received treatment for H. pylori, the risk of gastric cancer was 73% lower among persons in whom H. pylori eradication was achieved than among those in whom infection was persistent (HR=0.27). Adverse events were common in the treatment group than in the placebo group (53% versus 19.1%; P<0.001), but were mild.
It was concluded that among individuals with H. pylori infection and a family history of gastric cancer in first-degree relatives, H. pylori eradication treatment significantly reduced the risk of gastric cancer. Family History of Gastric Cancer and Helicobacter pylori Treatment. Choi IJ, Kim CG, Lee JY, et al. N Engl J Med 2020;382:427-436