Gallbladder cancer is the latest form of the disease that has been found to be increasing in people under 50, along with bowel, breast and lung cancer.
Data from the charity Cancer Research UK (CRUK) shows an 84 per cent increase in gastrointestinal cancer cases among Britons aged 24 to 49 since the early 1990s.
While a significant rise in cases of the disease has been seen in Britons of all ages, younger adults have seen the largest rise of any age group.
The world’s leading oncologists told MailOnline that while the reason for the “appalling” rise is uncertain, they suspect the modern diet could be to blame.
Specifically, experts believe the answer may lie in subtle changes in the trillions of bacteria in our gut (the microbiome) as a result of diets rich in ultra-processed foods.
It is well established that the risk of cancer increases with age, with most cases of the disease occurring after age 50.
But experts have noted a worrying rise in early-onset cancers, medically defined as incidences of the disease among those under 50 years of age.
Data from the charity Cancer Research UK shows an 84 per cent increase in gallbladder cancer cases in Britons aged 24 to 49 since the early 1990s. Image of the human digestive system of which the gallbladder is a part bile.
The gallbladder is an apple-sized organ near the liver and is primarily responsible for storing bile, a substance the body uses to break down the fats we eat.
Gallbladder cancer is relatively rare, with just over 1,000 cases diagnosed in the UK each year, which equates to around three a day.
But it is on the rise, particularly among younger people. CRUK data shows that almost twice as many young adults now contract the disease as in the 1990s.
However, the actual number of cases remains small, with only about 35 new cases per year among people aged 25 to 49, on average, compared with hundreds among older Britons who remain the most frequently diagnosed patients.
Professor Karol Sikora, a world-renowned oncologist with more than 40 years’ experience, said the rise had been clear for years.
He said the trend began in the 1990s, when the number of cases was “getting higher” while the age of patients was “getting lower.”
Professor Sikora, former head of the World Health Organisation’s cancer programme, said he suspected the cause was probably due to changes in modern lifestyle.
Specifically, a mix of pollution, alcohol, junk food, and increasingly stressful lives has a knock-on effect on the microbiome, which, in turn, can influence our cancer risk.
However, it is difficult to identify one or several factors responsible for the increased rates of early-onset cancer.
“It’s just impossible to measure… it’s a complex series of things that can affect it,” Professor Sikora said.
But he added that it was logical to see how these changes could have a cascading effect on organs involved in the digestive process, from the gallbladder to the colon, which has also seen an increase in early-onset cancer.
Professor Sikora also said it was interesting that despite what has been called the “sensible generation”, who, on average, drink less alcohol and eat healthier than their parents, they appear to have an increasing risk of cancer of the digestive system .
The oncologist said frustratingly there is very little advice that can be given to young people on how to reduce their risk.
However, he advised that eating plenty of fruits and vegetables and exercising regularly to avoid obesity can help.
Katrina Brown, senior director of cancer intelligence at CRUK, added: “Globally and in the UK, we are seeing an increase in rates of early-onset cancers, diagnosed in people aged 25-49.
‘While the increase may seem large for some types of cancer, it is important to remember that the actual change in cases is relatively small.
‘Cancer is still rare in this age group, with 90 per cent of cancer cases in the UK occurring in people aged 50 and over.
Symptoms of gallbladder cancer include jaundice, yellowing skin and eyes, itchy skin, and changes in the color of urine and stool.
‘However, this doesn’t change how difficult it is for anyone diagnosed with cancer.
Brown agreed that it was unclear what was causing the increase, but that factors such as obesity, genetics and better detection could be to blame, adding that more research was needed.
Symptoms of gallbladder cancer include jaundice (skin and eyes turning yellow), itchy skin, and changes in the color of urine and stool.
Only about one-sixth of patients with gallbladder cancer are expected to live 10 years after their diagnosis.
The increase in cancers among young people and the fact that scientists have so far been unable to pinpoint the cause worries some experts.
Oncologist Dr Shivan Sivakumar, from the University of Birmingham, described the situation as an “epidemic” earlier this year.