It's a worrying trend that we're seeing more of in recent headlines - otherwise healthy people under the age of 50 being diagnosed with cancer.
Evidence suggests more adults in their thirties and forties are getting cancer than ever before, leaving experts trying to figure out why. Take Kate, Princess of Wales, 42, who was told she has cancer after post-operative tests following abdominal surgery diagnosed the disease. She is known to lead a healthy lifestyle with plenty of exercise. The future Queen is now receiving preventive chemotherapy.
There was Manchester dad and avid mountain climber, Bobby Power, who died aged 40, seven months after a pancreatic cancer diagnosis. Followers were devastated by the former United youth footballer's decline from a fit and healthy young man as the disease progressed.
Just a few weeks ago, The Mirror reported the tragic story of Rebecca Gibson, a mum-of-two who was diagnosed with terminal bowel cancer - five years after first visiting the GP about her symptoms. She is just 36-years-old.
Thankfully, researchers are looking to find better treatments and cures, with the world's first personalised mRNA cancer jab for melanoma now being tested on British patients. The 'game-changing' jab, which is custom-built for each person and can tell the body to identify cancer cells and stop them returning, also has the potential to stop bladder, lung and kidney cancer.
Here, The Mirror takes a look at what studies and experts say about the trends of early-onset cancer, and the potential links between diet changes, damaging the gut microbiome with antibiotics and accelerated ageing cells...
What the statistics say
The latest global study shows the number of under-50s getting cancer has risen by almost 80 per cent in three decades - with early onset cancer increasing from 1.82million in 1990 to 3.26million in 2019. Meanwhile, the study, published in BMJ Oncology, showed cancer deaths of adults in their forties, thirties or younger grew by 27 per cent.
Cancer Research UK is looking into the recent rise. They say between the early 1990s and 2018, cancer incidence rates in 25 to 49-year-olds in the UK increased by 22 per cent. The surge is a bigger change than in any other age bracket - more than twice the nine per cent increase for over 75s.
But they warn that as striking as the figures are, early onset cancers are still uncommon. Dr Julie Sharp, head of health information at Cancer Research UK, told the Mirror: "Globally and in the UK, we're seeing a small increase in rates of early onset cancers, affecting people aged 25-49. Whilst the increase may look big, it's important to remember that 90 per cent of all cancers affect people over the age of 50.
"However, this doesn't change how difficult it is for anyone who is diagnosed with cancer. There isn't a clear answer to what's causing the rise, but preventable risk factors, genetics and improvements to early detection might all play a part.
"More research is needed to examine the causes of early onset cancer, so we can better understand why more people under 50 are being diagnosed with the disease. One of our new Cancer Grand Challenges teams has been awarded up to £20m to investigate the rise, and our BCAN-RAY study is looking at new ways to identify younger women at higher risk of breast cancer."
Diet change clue and bowel cancer
Dr Shuji Ogino, a professor at Harvard University in the US, and Dr Tomotaka Ugai, a research fellow at Harvard, have been looking at changes to potentially explain the rise of incidents of cancer in younger people. They looked at how our lifestyles and environment can affect the way diseases evolve and progress.
Their first clue was an economic boom in the 1950s following World War II, and following this, cancer cases in younger people were actually detected in wealthier nations. New products were all the rage, along with low-effort fast food.
The two scientists started investigating bowel cancer in particular, after finding early-onset rates were increasing from the 1990s - when people born in 1950 started developing the disease much earlier than generations before them. Evidence shows that lifestyle and diet changes contribute to a rise in cancer in over 50s, because as people get older, changes develop in their cells.
But early life exposures to the same risks could see the chances of developing cancer start sooner. "From our data, we observed something called the birth cohort effect," Ogino explained. "Since 1950, we found that each successive generation has a higher risk of early-onset cancer. Someone born in 1960 has a higher risk than someone born in 1950, and someone born in 1970 has a higher risk than someone born in 1960. It's just continuing."
The link was most common in bowel cancer - which has increased by around 50 per cent in the UK since the mid-1990s. "Many risk factors are actually shared in many cancer types," Ogino pointed out. "Obviously, the whole body is interconnected, and, with food, there's a line from the mouth to the anus."
Of the 12 cancer types the study found that were increasingly common in those under 50, eight were related to the digestive system. "Our diet has changed a lot," Ogino continued. "We eat more processed and refined food and sugar. That might be a clue, but we don't know exactly how different factors might have contributed to the increase in early-onset cancers."
The latest global study on the number of under-50s getting cancer was led by the University of Edinburgh and Zhejiang University School of Medicine in Hangzhou, China. The highest rates of early onset cancers were in Western Europe and North America.
Based on the trends, the researchers believe diets high in red meat and salt, while being low in fruit and milk, along with alcohol and tobacco use, were the main risk factors in common cancers among under-50s. They also cited physical inactivity, excess weight, and high blood sugar. The experts estimate that by 2030, early onset cancer cases will rise by another 31 per cent, with people in their 40s the most at risk.
Gut microbiome
Researchers are particularly interested in how what we eat, and diet changes over the decades, have affected the microbiome - which is the bacteria that live in our digestive system and contribute to our health and immune system. Looking at Ugai and Ogino's study of the birth cohort effect, they have argued it's also important to study at how diet changes while we are young can change the balance of bacteria in our guts, and act as a risk factor for early-onset cancer.
In an American study published last month, researchers found a specific subtype of a microbe commonly found in the mouth is able to travel to the gut and grow within colorectal cancer tumours. This microbe is also a culprit for driving cancer progression and leads to poorer patient outcomes after cancer treatment, the study said.
"We've consistently seen that patients with colorectal tumours containing fusobacterium nucleatum have poor survival and poorer prognosis compared with patients without the microbe," explained Susan Bullman, Ph.D., Fred Hutch cancer microbiome researcher and co-corresponding study author. "Now we're finding that a specific subtype of this microbe is responsible for tumour growth. It suggests therapeutics and screening that target this subgroup within the microbiota would help people who are at a higher risk for more aggressive colorectal cancer."
Levels of fusobacterium have been linked to diets high in processed meat and carbonated drinks. Meanwhile, new research is currently being considered that suggests that the increase in intestinal fungal infections and the use of antibiotics may be a large contributor to cases of colon cancer - which is the number two reason for premature death in adults under 55.
According to Fight Colon Cancer, a non-profit organization, the number of individuals under 55 being diagnosed with colorectal cancer has nearly doubled in just a decade. The death rate has risen 90 percent in the last two decades.
The Center for Disease Control and Prevention (CDC) says 30 percent of the roughly 154 million antibiotics doctors prescribe yearly are "medically unnecessary," and contain ingredients that is killing off important bacteria in the gut. Sarah Perrott, a researcher from the University of Aberdeen, says that "the right hand side of the bowel has greater diversity of bacteria.
"So it all makes sense when we think about the contents of the bowel, the activity of the gut microbiome and the theory of bowel cancer development." Although her study, published last year, showed few links between antibiotics and colon cancer, nearly every other type of cancer diagnosis was associated with the overuse of antibiotics.
Another study done in Sweden, on the other hand, did show an absolute link between antibiotics and rectal cancer, along with a more recent study from the UK. Cynthia L. Sears, PhD, a professor of medicine and oncology at Johns Hopkins University School of Medicine in Baltimore, Maryland, co-authored a 2021 that UK study stated, "we would never say that this is more than associations. But the fact that they are reproducible elements, really, across very different populations makes you think that this could be real".
The UK study did also show that the use of antibiotics occurred at least a decade before the diagnosis, suggesting that this medication takes some time before the drugs have a serious impact. Perrott goes on to say that, "antibiotic use is very common, and it is important to note that not everyone who uses antibiotics will get bowel cancer. However, while invaluable in medicine, antibiotics should be used appropriately and only when necessary."
Secret advanced ageing cells
Researchers in America believe higher cancer rates in younger people could be to do with cells ageing beyond their years. A new study, by researchers at Washington University, found that those with above-average accelerated ageing had a 17 per cent higher risk of developing a cancerous tumour.
Cells control every bodily function, and as they age, their ability to repair themselves reduces. The experts tracked data from almost 150,000 people in the biomedical data UK Biobank. Analysing blood tests, they worked out a person's biological age, and how old a person's cells and tissues were.
One test marker included albumin - a protein produced by the liver, which works to keep fluid from leaking out of blood vessels. This reduces with age, while the size of red blood cells increases with age, making them less able to divide and multiply.
Faster ageing of cells can be credited to more stressful lifestyles, worsening mental health, obesity, and sedentary lifestyles. Ruiyi Tian, a Washington University graduate student and the study's first author, said: "Unlike chronological age, biological age may be influenced by factors such as diet, physical activity, mental health, and environmental stressors.
"Accumulating evidence suggests that the younger generations may be ageing more swiftly than anticipated, likely due to earlier exposure to various risk factors and environmental insults." Those that scored the most for accelerated ageing cells had double the risk of developing early-onset lung cancer, the study showed.
They also had a 60 per cent higher chance of a stomach tumour, and an alarming 80 per cent higher risk of developing uterine cancer. Dr Anna Blaes, an expert in the effect of biological ageing in cancer survivors at the University of Minnesota, says lungs can be at a greater risk to ageing compared to other tissues due to their inability to regenerate.
Other areas of the body can be linked to inflammation, such as intestinal cancers, which get worse with ageing. Dame Laura Lee, chief executive of Maggies', says they have been a rise in younger patients seeking support from the cancer charity.
She told the Mirror: "It is interesting to see there is now some research coming out which shows that encouraging a healthy lifestyle could reduce early-onset cancer disease burden. We are certainly aware of an increase in younger people coming to us for support after diagnosis and at that point, people often want to reflect on how they came to have cancer.
"And what we do know is how small lifestyle changes even after diagnosis can make a huge difference in helping people to ‘get ready’ both mentally and physically for cancer treatment. We have been piloting Pre-hab workshops in Scotland for the last few years, now being rolled out across the UK, to empower people to make small changes to lifestyle, diet and exercise. This can help people feel more in control and be in as good a place as possible to start treatment. Small changes can even make treatment easier and can help with recovery as well."