Katy Lander was 32 when she was diagnosed with bowel cancer after months of bloating, exhaustion and abdominal pain initially attributed to stress.
The mother of two, who works as a GP administrative assistant in a village near Worksop, Nottinghamshire, first sought medical advice while managing family responsibilities, renovating a house and preparing for her wedding.
Her doctor suggested that she was run down and stressed, an explanation Katy initially considered plausible given the pressures she was experiencing.
However, her symptoms persisted, and about seven months later she began experiencing changes in her bowel habits. Sometimes she needed to use the toilet immediately after eating, while on other occasions she suffered constipation throughout the day.
Blood in Stool Prompted Further Medical Investigation
As her condition continued, Katy contacted her GP surgery again but was told she would have to wait four weeks for a telephone appointment.
By the time she spoke to a doctor in June 2024, she had begun noticing blood in her stool and was experiencing severe stomach pain intermittently.
Katy said she was frightened that the symptoms indicated bowel cancer. However, the doctor reassured her that her age made the disease less likely and suggested irritable bowel syndrome as a possible explanation.
She was asked to attend the surgery for an examination a few days later and was also given a faecal immunochemical test (FIT), which checks a stool sample for blood that could indicate bowel cancer.
After returning the sample the following morning, Katy was referred for an urgent colonoscopy the next day.
The examination identified 13 polyps, which are small growths, as well as a large mass in her bowel.
Surgery and Chemotherapy Followed Cancer Confirmation
Further investigations, including biopsies and a CT scan, confirmed that Katy had bowel cancer.
She recalled being in shock when a consultant delivered the diagnosis alongside her husband, Ollie, who was 31 at the time.
Her first question was whether the cancer had spread.
Just days after her 33rd birthday, Katy underwent keyhole surgery to remove the tumour and approximately one-third of her bowel. Fortunately, the cancer had not spread into nearby organs.
She began three rounds of chemotherapy four weeks later, but experienced severe side effects, including nausea and painful ulcers and blisters inside her mouth.
Katy completed treatment in December 2024 and was told three months later that she was in remission.
She described the news as a huge relief after what had been a difficult period.
Young Adults Are Facing Rising Bowel Cancer Rates
Katy said she had no obvious established risk factors for the disease, explaining that she had always tried to look after herself.
Bowel cancer is more commonly diagnosed in older people, particularly those in their 70s and 80s. However, increasing numbers of younger adults are developing the disease, including people with few recognised risk factors.
In the UK, bowel cancer rates among people aged 25 to 49 have risen by more than 50 per cent since the early 1990s, according to a major international study published in The Lancet Oncology in 2024.
The research identified England as having the fastest increase in bowel cancer rates among younger adults in Europe.
Scientists are now investigating the possible reasons behind the trend through a major research programme launched by King’s College London.
PROSPECT-UK Study to Investigate Possible Causes
The PROSPECT-UK study aims to recruit 250,000 people aged between 18 and 50.
Researchers will collect information about participants’ diets, lifestyles and environmental exposures, alongside blood and stool samples. These findings will then be compared with NHS records over the following years.
Similar studies are being conducted in France, India, Italy and the United States as part of the wider international PROSPECT project.
Professor Andrew Chan of Harvard Medical School, who co-leads the international research team, said differences between generations could provide important clues.
People born after the 1970s have grown up in a different food environment and experienced changes in obesity rates, metabolic conditions, medication exposure and other environmental factors, he explained.
Researchers are examining whether several of these influences could affect the same biological processes and contribute to bowel cancer developing at younger ages.
Scientists Examine Obesity and Accelerated Biological Ageing
One area of investigation is metabolic health, particularly obesity and type 2 diabetes, both of which have become more common among younger adults.
Excess body fat, especially around internal organs, can contribute to chronic inflammation and reduce the body’s sensitivity to insulin, the hormone that regulates blood sugar.
When the body becomes less sensitive to insulin, it may produce more of the hormone to compensate. Insulin also encourages cells to grow, raising concerns about its potential role in the development of abnormal cells.
Inflammation can damage the lining of the bowel, requiring the body to replace affected cells more frequently. Researchers are investigating whether this process increases opportunities for DNA errors that can contribute to cancer.
Professor Chan said people of the same chronological age might not necessarily be ageing biologically at the same rate.
As people age, damage accumulates in cellular DNA, while the body’s ability to repair that damage or eliminate abnormal cells can become less effective. Scientists are investigating whether an earlier onset of these processes could help explain some cases of bowel cancer in younger adults.
Research associated with the international PROSPECT project has already identified a link between accelerated ageing in fat tissue and bowel cancer among younger people.
Ultra-Processed Foods and Low Fibre Intake Under Investigation
Ultra-processed foods, including ready meals, packaged snacks and sugary drinks, are another area of scientific interest.
These foods account for around 60 per cent of the calories consumed in Britain. A report published in the European Journal of Nutrition in 2024 also found that almost two-thirds of the calories consumed by British teenagers came from ultra-processed foods.
Research published in JAMA Oncology last November found that women under 50 who consumed the highest amounts of ultra-processed foods had 45 per cent higher odds of having precancerous bowel growths than women who consumed the least.
Researchers have cautioned that the findings do not establish that food processing itself causes the growths. People who consume more ultra-processed foods may also eat more calories, consume less fibre or gain weight.
Fibre supports gut health by helping beneficial bacteria produce substances such as butyrate. This compound, generated when gut bacteria break down fibre from foods including vegetables, fruit and wholegrains, helps maintain the bowel lining and regulate inflammation and abnormal cell growth.
A study published in Nature Metabolism last year found that butyrate slowed the growth of bowel cancer cells in laboratory experiments by affecting genes involved in cell multiplication.
Researchers are also examining whether low fibre intake encourages gut bacteria to break down more protein, producing substances that may harm the bowel lining.
Sylvia Zanesco, a nutrition researcher at King’s College London, is investigating whether increasing fibre consumption can improve changes associated with bowel cancer risk. Her research includes a 12-week study involving identical twins under 55.
Food Additives May Also Affect the Gut
Scientists are investigating the possible effects of additives used in ultra-processed foods, including emulsifiers that prevent ingredients from separating in products such as sauces and ice cream.
Zanesco said there was growing evidence suggesting that some emulsifiers could affect the gut and promote inflammation.
Katy said she had previously relied on convenience foods, including pizzas, chicken Kievs and soup, and had not paid much attention to her fibre intake.
Since her diagnosis, she has changed her eating habits and now checks food labels more carefully. She has also started preparing more meals from scratch.
She aims to consume 30 grams of fibre daily, incorporating more nuts, seeds, fruit and vegetables into her diet.
Antibiotics and Changes to Gut Bacteria Examined
The possible role of antibiotics is another focus of research into bowel cancer among younger people.
Government figures show that antibiotic prescriptions in England increased by 21 per cent between 1980 and 1988, rising from 32.8 million to 39.8 million.
Research covering 73 countries and published in The Lancet Global Health in 2020 found that antibiotic use among children under five increased from 36.8 per cent in 2005 to 43.1 per cent in 2017.
Antibiotics can eliminate beneficial bacteria alongside harmful organisms, potentially allowing certain bacteria to multiply with less competition.
A study published in the British Journal of Cancer in 2022 linked antibiotic use to a 49 per cent increase in bowel cancer risk among people under 50.
Professor James Kinross, a colorectal surgeon and researcher at Imperial College London, believes disruption to gut bacteria could help explain some of the increase in younger-onset bowel cancer.
He said harmful bacteria can cause inflammation that damages the bowel lining. As the body replaces damaged cells, there may be more opportunities for errors to occur when DNA is copied.
Researchers have also investigated colibactin, a substance produced by certain strains of E. coli bacteria, for its potential to damage bowel cells long before cancer develops.
Some strains, known as pks-positive E. coli, can live in the bowel without causing symptoms. Around one in five healthy people carries these bacteria, and babies may acquire them from their mothers around birth.
Colibactin Linked to DNA Damage in Younger Patients
Scientists are still investigating why these bacteria may contribute to cancer in some people but not others.
Research published in Nature Microbiology last year found that a low-fibre diet increased bowel inflammation in mice, allowing certain bacteria to multiply.
The resulting activity may damage DNA within bowel cells, including the APC gene, which normally helps prevent cells from multiplying uncontrollably.
A separate study published in Nature in 2025 examined 802 bowel cancer tumours and identified signs of DNA damage associated with colibactin in approximately one in five cases.
The damage was 3.3 times more common among patients diagnosed before the age of 40 than among those aged over 70.
Professor Ludmil Alexandrov, a cancer researcher at the University of California San Diego who led the study, said the exposure could give some bowel cells an early advantage in accumulating mutations.
Pesticides and Forever Chemicals Under Scientific Scrutiny
Researchers are also exploring whether environmental chemicals could contribute to the rise in bowel cancer among younger adults.
A study published in Nature Medicine in April identified a possible association between bowel cancer in people under 50 and picloram, a weedkiller used in agriculture.
When researchers compared tumours from younger patients with those from people over 70, the younger patients were more likely to have DNA changes associated with exposure to the chemical.
The study also found that areas in the United States with greater picloram use tended to have higher rates of bowel cancer among younger adults.
Another area of concern is per- and polyfluoroalkyl substances, commonly known as PFAS or forever chemicals. These substances are used in products including non-stick cookware, waterproof clothing and some food packaging.
In a laboratory study published in Environmental Science & Technology in 2023, Yale University researchers exposed bowel cancer cells to two PFAS chemicals, PFOA and PFOS.
The chemicals increased the mobility of the cancer cells, a change associated with the ability of tumours to spread. However, laboratory findings do not by themselves establish that exposure causes cancer in humans.
Earlier research published in 2005 found that PFOA levels in people’s blood more than doubled between 1974 and 1989, raising questions about possible long-term exposure among people who are now developing cancer in their 30s and 40s.
Microplastics Raise Further Questions About Bowel Health
Microplastics are also being investigated as a possible factor.
A review published in Cancer Epidemiology last year reported that microplastics had been identified in bowel tumours.
Scientists are examining whether these particles could irritate the bowel lining, cause inflammation or interfere with gut bacteria.
Researchers are particularly interested in exposure during childhood, when the bowel and immune system are still developing.
Research published in Pediatric Research in July highlighted concerns that children may take in more microplastics relative to their body weight than adults, while their organs and immune systems are still developing.
The possible contribution of microplastics to bowel cancer remains under investigation.
Researchers Investigate Whether Extreme Endurance Exercise Plays a Role
Although regular physical activity is known to help protect against bowel cancer, researchers in the United States have also examined whether repeated participation in marathons and ultramarathons could have different effects.
A study published in Cancer Epidemiology in August examined 94 endurance runners aged between 35 and 50 who had completed at least five marathons or two ultramarathons.
The researchers found that 15 per cent had advanced adenomas, which are bowel growths that can sometimes develop into cancer.
Dr Timothy Cannon, an associate professor at the University of Virginia School of Medicine who led the research, suggested that repeated endurance events might reduce blood and oxygen supply to the bowel.
He said this could potentially cause recurring cell death and abnormal cell division. The findings require further investigation and do not establish that endurance running causes bowel cancer.
Katy Lander Continues to Live With Fear of Recurrence
Despite being in remission, Katy said the possibility of her cancer returning remained a source of anxiety.
She has decided not to return to work and instead wants to spend more time with her children, who are now eight and five.
Although she is cancer-free, she described the emotional challenge of balancing everyday life with the fear of another diagnosis.
For Katy, the reasons she developed bowel cancer at such a young age remain unanswered.
Experts Highlight Metabolic Health as an Area to Address
As researchers investigate possible causes of rising bowel cancer rates among younger adults, Professor Chan said metabolic health should be a priority.
Scientists are continuing to examine how diet, obesity, gut bacteria, antibiotic exposure and environmental chemicals may interact, rather than assuming that one factor explains the trend.
The PROSPECT-UK study is expected to help researchers investigate these potential influences by combining information about participants’ lifestyles and exposures with biological samples and NHS records.
Further findings may help clarify why bowel cancer is increasingly affecting younger people and identify ways to reduce the risk.
