The Global Burden of H. pylori: A Call for Stomach Cancer Prevention Programs

Helicobacter pylori, H. pylori for short, is a common bacterium that infects the stomach. Up to half of the world’s population may have H. pylori infection at some point in their lives. However, not everyone has symptoms. The infection can cause inflammation and is the leading cause of gastric and duodenal ulcers. Chronic H. pylori infection is also known to cause stomach cancer.

Although the pathogen is seemingly ubiquitous, H. pylori can be effectively eradicated with antibiotics and acid reducers, all of which are available in lower-cost generic forms. A clinical guideline from the American College of Gastroenterology recommends a bismuth quadruple therapy for 10 to 14 days as first-line treatment. The cocktail includes a proton pump inhibitor, such as omeprazole or lansoprazole, bismuth subcitrate or subsalicylate, tetracycline, and metronidazole. Other regimens may use amoxicillin or clarithromycin.

Stomach cancer is the fifth leading cause of cancer death globally and one of the five most common types of cancer, with rising incidence rates in people younger than age 50. According to the American Cancer Society, it's estimated that about 30,300 new cases of stomach cancer in the U.S. have been detected for stomach cancer this year—affecting roughly 17,720 men and 12,580 women.

Up to half of the world’s population may have H. pylori infection at some point in their lives.

Since H. pylori infection is a modifiable cause of stomach cancer, it would stand to reason that treatment with antibiotic and proton pump inhibitor combinations would reduce the cancer incidence rates. Preventative measures require the implementation of screening programs to identify individuals who would benefit from H. pylori treatment.

In a study published earlier this month in Nature Medicine, scientist Jin Young Park, from the early detection, prevention and infections branch of the International Agency for Research on Cancer, World Health Organization, and her colleagues analyzed data on the incidence of stomach cancer from 185 countries among people born between 2008 and 2017. The researchers further estimated the number of potentially preventable cancer cases caused by H. pylori infection.

The analysis predicted that without intervention, 15.6 million people born between 2008 and 2017 worldwide would be newly diagnosed with gastric cancer. The majority of cases (68%) would be in the Asian continent, another 13% would be from the Americas, and 11% would be in Africa.

Among all cases, about 76% are attributable to H. pylori infection, therefore potentially preventable with screening and treatment. Of these, 67% are in Asia, 13% in the Americas, and 12% in Africa. In Asia, the number of stomach cancer cases attributable to H. pylori is higher in men compared with women (71% versus 61%). In Africa, the prevalence is higher among women than among men (16% versus 9%).

When assessing screen-and-treat strategies, Park and her colleagues found that the expected number of stomach cancer cases could be reduced by up to 75%.

Given these results, the authors advocate for the implementation of screening and prevention programs, especially in areas where incidence rates are projected to increase the most.

“Our results endorse the importance of making changes to the current practice and urge regional health systems to be prepared to manage the growing burden of this largely preventable disease by planning pilot and feasibility projects, including H. pylori screen-and-treat programs,” the authors wrote.