A common bacteria is fuelling millions of cases of stomach cancer worldwide – but screening may turn the tide, experts have said.
Scientists from the International Agency for Research on Cancer (IARC) – part of the World Health Organisation – project that, if nothing is done, around 15.6 million people across the globe born between 2008 and 2017 will be diagnosed with stomach (gastric) cancer in their lifetime.
Of these cases, some 11.9 million (76%) will be due to infection with Helicobacter pylori (H. pylori).
While the vast majority of new cases will be in Asia (particularly India and China), some two million could occur in the Americas, 1.7 million in Africa and 1.2 million in Europe.
H. pylori is a bacteria that infects the lining of the stomach and is thought to be spread from person to person and via contaminated food and water.
Research is still ongoing into how the infection is spread and how it may cause stomach cancer and another type, non-Hodgkin lymphoma.
For many people, H. pylori does not cause issues and will not need the standard treatment of antibiotics, but it can be the cause of ongoing indigestion, bloating or nausea.
H. pylori is detected with a blood test, breath test or via a stool sample.
The authors of the latest study are now calling for greater investment in the prevention of stomach cancer, particularly through population-wide “screen and treat” programmes for H. pylori.
However, Cancer Research UK said stomach cancer rates in the UK have actually been falling – over the last decade, they have dropped 26% and are projected to fall further by 2040.
Health information manager at Cancer Research UK, Dr Rachel Orritt, said: “H. pylori infection increases the risk of stomach cancer, but it’s not a common infection in the UK.
“It’s also important to note that stomach cancer cases have been decreasing in the UK for decades, and they’re expected to continue to fall.
“Although this is an important issue worldwide, in the UK other preventable factors cause more cancer cases.
“Ways to reduce your cancer risk include stopping smoking, keeping a healthy weight, cutting down on alcohol and eating a healthy, balanced diet.”
For the Nature Medicine study, scientists examined the incidence of stomach cancer from 185 countries in 2022 and combined it with projections of future deaths.
They looked at the potential impact of screen-and-treat strategies for H. pylori and found the number of stomach cancers could be cut by up to 75% overall.
Asia accounts for two thirds of projected future cases, with 10.6 million cases (68% of the total), followed by the Americas (2m or 13%), Africa (1.7 million or 11%), Europe (1.2m or 8%), and Oceania (0.07m or 0.4%).
Dr Jin Young Park, leader of the gastric cancer prevention team at IARC and co-author of the study, said: “It is essential that health authorities make gastric cancer prevention a priority and accelerate efforts to control it by planning pilot and feasibility projects, including H. pylori screen-and-treat programmes.”
The main symptoms of stomach cancer include heartburn or acid reflux, having problems swallowing, feeling or being sick, indigestion and burping and feeling full very quickly when eating.
These symptoms are common and usually caused by other conditions.
Other symptoms include loss of appetite or losing weight without trying, stomach pain, a lump feeling at the top of the stomach and feeling very tired.
