Daijiworld Media Network - Geneva

Geneva, Jul 8: A silent bacterial infection found in the stomach lining could be behind millions of future stomach cancer cases worldwide, according to a new study by the International Agency for Research on Cancer (IARC), part of the World Health Organisation.

The study, published in Nature Medicine, warns that Helicobacter pylori or H. pylori infection could cause nearly 12 million stomach cancer cases among people born between 2008 and 2017. Researchers project that 15.6 million people from this group may be diagnosed with gastric cancer in their lifetime, and 76 percent of those cases may be linked to this bacterium.

H. pylori, a highly infectious bacterium often contracted through contaminated food, water, or close contact, typically causes no symptoms but can silently damage the stomach lining over time. It has been classified as a class I carcinogen by global health agencies and is widely prevalent in countries with poor sanitation and overcrowded living conditions.

Though many infected individuals may never show symptoms, H. pylori can lead to chronic inflammation, ulcers, and eventually stomach cancer. The study notes that about half the world’s population hosts the bacterium, and around 90 percent of non-cardia gastric cancers can be traced back to it.

The researchers analysed cancer incidence in 185 countries in 2022 and found that Asia alone could account for 68 percent of the future cases, followed by the Americas, Africa, Europe, and Oceania. The risk is highest in countries with limited access to early diagnosis and treatment.

Dr Jin Young Park, co-author of the study and head of IARC’s gastric cancer prevention team, said the findings should serve as a wake-up call for governments to launch targeted screen-and-treat programmes for H. pylori. He said these efforts could reduce the number of future cases by up to 75 percent.

The bacterium becomes cancer-causing when certain virulent strains, especially those with the cagA gene, trigger chronic inflammation and damage the DNA repair mechanisms of stomach cells. Other contributing factors like smoking, high salt diets, obesity, and genetic makeup can increase the cancer risk further.

Gastric cancer is the fifth most common form of cancer globally and causes about 770,000 deaths each year. It is often diagnosed late due to mild or no early symptoms, which is why early detection is critical. Endoscopy, breath tests, and stool tests are effective screening methods.

Current treatment for H. pylori infection involves a two-week regimen combining antibiotics with acid-reducing drugs. However, increasing antibiotic resistance remains a concern and may require multiple rounds of treatment.

The study underscores the urgent need for public health systems to adopt preventive strategies and prepare for a potential rise in stomach cancer cases over the next decades.