New theory that could explain ‘disturbing’ rise in young people with stomach cancer – doctors suspect a common infection could be to blame

Scientists are probing the causes of stomach cancer after a ‘disturbing’ rise in young adults with the disease.

Although cases are falling in older people, in the past few years has been an annual two per cent uptick in under 50s being diagnosed, leaving experts baffled.

Worryingly, in half of these cases the cancer is already advanced — meaning it is ‘almost a death sentence’, with just a four per cent survival rate. 

Now, concerned doctors have launched a new study to find out if the common bacteria H. pylori, which also causes stomach ulcers, could be to blame.

If the theory holds, it throws open the possibility that simple antibiotics could be offered to high risk patients in a bid to prevent cancer from ever developing.

Zak with his nephew, days after his terminal cancer diagnosis. Doctors have launched a new study to find out if H. pylori could be to blame for the rise in young stomach cancers

Dr Jessica Sheth Bhutada, a pediatric oncologist at Children’s Hospital Los Angeles, was part of the team that first charted the rise in younger stomach cancer patients.

She told healio.com: ‘We don’t have a clear reason for why this is happening; it’s a worldwide phenomenon.

‘There’s no literature to explain why we’re seeing this disturbing trend. 

‘We have some ideas, since in colorectal cancer we know that potential [triggers] include changes in dietary patterns, antibiotic usage and alterations of the gut microbiome.

‘However, there are no studies investigating if and how this might be related to the rising incidence of stomach cancer.’

This, says Dr Sheth Bhutada, prompted her current study. 

‘[We want] to try to understand why young adults are getting stomach cancer and how can we potentially catch it earlier and even prevent it,’ she said.

‘The goal is to do a multi-level analysis on individual factors, such as chronic H. pylori infection, obesity risk and connecting that with a patient’s neighborhood risk factors, such as living in food deserts [a neighborhood with limited access to fresh and nutritious produce] or access to health care. 

A coloured microscope image of a human stomach (blue) infected with Helicobacter pylori bacteria (red) 

The World Health Organisation (WHO) said that aggressive strains of H. pylori among the most dangerous superbugs, posing a big threat to the human race

‘How do these influence a person’s risk for developing stomach cancer, particularly when they’re young?’

H. pylori, or Helicobacter pylori, is a type of bacteria that 40 per cent of people carry in their stomach. 

In between 80 and 90 per cent of cases it doesn’t cause symptoms, however it can trigger stomach ulcers, indigestion, bloating or nausea.

H. pylori can be detected with a blood, breath or stool sample test — and treated with antibiotics and other medicines.

It is known that long-term H. pylori infection is a cause of some stomach cancers in older adults. 

Other factors, such as smoking and diet, can increase the risk of H. pylori leading to cancer, according to Cancer Research UK.

In China aggressive testing for and treating of the bug has led to a drop in cases.

Experts young people may ignore symptoms of stomach cancer meaning cases are not diagnosed until the disease is advanced and incurable

However Dr Sheth Bhutada said: ‘The challenge is that we don’t know to what extent H. pylori infection drives stomach cancer in young adults and whether or not [the Chinese approach] would be an effective strategy.’

One young case, Zak Wilcox, was just 40 when he died of stomach cancer in 2021. 

As reported by MailOnline, his mother Rebecca believes he was infected with H. pylori during a backpacking trip to India in his late teens. 

In India, H. pylori is carried by 80 per cent of the population and Zak developed a food-poisoning-like illness. 

In the years after, he suffered indigestion before more severe stomach pain prompted a visit to his GP and that landed him in hospital.

Of his diagnosis in 2020 Ms Wilcox said: ‘I couldn’t believe Zak had cancer — he was apparently fit and healthy, had a good diet, and only drank socially. It was terrible.’

The software engineer died just three months after the tumour was detected.

Ms Wilcox has since started a campaign to raise awareness about a £7 test that can detect H. pylori — believing it triggered her son’s cancer.

The new research comes amid growing concern that more adults under 50 are getting cancer than ever before.

Over the last 30 years, young diagnoses — of all types — have shot up by 80 per cent across the globe, and 25 per cent in the UK, according to a 2023 international analysis.

Cancer deaths of adults in their 40s, 30s or younger grew by 27 per cent during the same period.

While the reason for this isn’t yet totally clear, earlier this year Professor Charles Swanton, oncologist and Chief Clinician at Cancer Research UK highlighted concerns about increasing consumption of ultra-processed food and colorectal cancers.

Speaking at the American Society of Clinical Oncology annual meeting he said studies have shown that some early-onset cases may be ‘initiated’ by bacteria in the gut that’s prevalent in those who eat low fibre, high sugar diets.

Dr Sheth Bhutada added: ‘I worry that diet is a big factor [in stomach cancers too], but we don’t know which specific dietary risk factors are out there. 

‘For example, we know for colorectal cancer, having a high-fiber diet and limited exposure to red meats can be helpful preventive measures, but the stomach environment is different than the colon. 

‘This speaks to the fact that there’s little known about this disease, especially in younger patients.

‘We anticipate having some publishable results within the next six to 12 months, so we can finally start to make an impact in this deadly disease.’