There aren’t many things in life you run straight into without testing first. Plays need rehearsals, restaurants need test kitchens, and researchers need feasibility studies.

Think about pilot and feasibility studies like the first walk-through of a play. You’re planning a large-scale production, and you want it to be a success – you can’t just go straight into the performance. First, you need to suss out: have you got the script right? Can you get the actors in the roles? Will the show be a hit?

It’s the same with feasibility studies. Before you run a big trial, with a lot of time, funding, and resources thrown into it, you need to figure out whether the whole thing is actually possible!

What do pilot and feasibility studies aim to achieve?

The aim of both pilot and feasibility studies, yes – you’ve guessed it – is to see if a study is feasible. A pilot study tests the exact design of a larger future trial; it’s essentially a mini version. A feasibility study differs in that it doesn’t have to follow the exact design of the planned trial, instead it can explore various aspects of the study’s design to find out what works best.

These studies are the prime time to ask key questions and put them to the test in real life. These include questions about:

• Recruitment and retention: can you realistically get enough people to take part in the trial? And not only will they sign up, but will they stay for the whole duration?
• Acceptability and adherence: are participants and staff happy with the study plan and assessments that are carried out? And do they follow it as planned?
• Data: is the data collected reliable, complete, and good quality?
• Resources: have you factored in all the relevant ingredients? Do you have enough time, staff and money to run it as planned?
• Method: is this study recipe one that can be followed smoothly?
• Safety: are there any safety concerns that could prevent scaling up?

Without testing, it can be hard to know. The science could be spot on, the study beautifully designed, but if participants don’t like it or professionals find delivering it a burden, then you don’t have a successful trial on your hands.

Therefore, researchers take this chance to identify and explore potential challenges before the main trial begins. By tackling these issues early, you’re less likely to face unexpected problems or setbacks further down the line.

Feasibility studies also represent the first touch point with real people that could be involved in the research. This allows the target group to be the central focus and understand what works for them. This opens up the opportunity for researchers, clinicians, and participants to collaborate and learn how best to conduct the study.

Funding pilot and feasibility studies

Once you’ve got the findings from your feasibility trial, it’s going to be much easier to progress to running the actual trial, because you’ve rehearsed it. Not only that, but it will also help secure the funding needed to run the bigger trial. After all, they’re not cheap. Being able to show pilot or feasibility data to funders proves that you’re coming to them with a tried and tested plan, boosting the chances that the main trial will be achievable.

That’s why at World Cancer Research Fund International, we offer specific grants for pilot and feasibility studies, as part of our Regular Grant Programme. These are for shorter time periods, with lower budgets than our investigator initiated grants.

Sometimes they prove to work well and achieve the intended results.

Dr Campbell

One example is our grant holder Dr John Campbell, who ran a pilot trial to assess whether a 16-week exercise programme for people with chronic lymphocytic leukaemia (a type of rare cancer of the blood and bone marrow) was safe and acceptable.

The study concluded that the programme was both safe and feasible, and even showed an increase in muscle mass and reductions in fat around the lower body.

Dr Campbell and his team also received positive feedback from the participants in the study, with one saying:

“I have strong memories of the trial. It came into my life during some dark days and gave me a sense of routine and a newfound purpose. I’m so grateful for the opportunity to meet the researchers, though I wish it had been under different circumstances.”

Dr Campbell and his team now plan to use this small-scale study to inform a larger trial that will, for the first time, assess the tumour-suppressing effects and mechanisms of exercise in chronic lymphocytic leukaemia.

Sometimes pilot studies can highlight challenges and important considerations for a study’s design. And these results are just as important.

Not only does this save a lot of time and money on a trial that won’t succeed, but it’s also an essential way to learn what doesn’t work, so other researchers can avoid encountering the same issues.

Prof Craike

Take, for example, a project led by grant-holder Prof Melinda Craike and funded by our network charity Wereld Kanker Onderzoek Funds. The study examined the feasibility of a nurse-delivered physical activity promotion intervention for prostate cancer survivors living in socio-economically disadvantaged areas. Recruitment was low, and both nurses and survivors reported only low to moderate acceptability. Survivors highlighted barriers such as a lack of interest, perceived cost, other health concerns, and a preference for advice from their general practitioners.

Rather than going ahead with a costly full-scale trial, Prof Craike and her team concluded the intervention was not feasible in its current form. Importantly, they also offered guidance for future research, such as exploring incentives for participation, involving GPs in delivery, and using community-based participatory approaches.

Prof Craike explains:

Pilot and feasibility studies might not always produce the results researchers expect, but they always offer valuable insights. I encourage the publication of feasibility studies, including those that are unsuccessful, to reduce waste and duplication, and to inform the development of future research efforts. Even though they are often unpublished, reporting unsuccessful feasibility studies like ours is essential to protecting research resources and guiding future projects.

Far from being ‘failures’, pilot and feasibility studies are crucial for developing smarter, more sustainable research.

The UK Women’s Cohort Study (UKWCS), which we provided initial funding for, recently celebrated its 30th anniversary! This is an incredible achievement because many research projects only last a couple of years. Such a long-term project can provide scientists with richer, more detailed information to help prevent cancer.

The UKWCS, led by Prof Janet Cade from the School of Food Science and Nutrition at the University of Leeds, is one of the largest cohort studies investigating diet and cancer in the UK, comprising over 35,000 middle-aged women and representing a wide range of different eating patterns, which can help scientists research what protects against cancer and coronary heart disease. Participants are regularly followed up to examine what effect food and nutrient intakes have on their long-term health.

We spoke to Dr Renate Winkels (pictured) and Dr Laura Winkens, at Wageningen University & Research, to discover more about their studies in bowel (also known as colorectal) cancer.

Your team looked at what influences people’s health behaviours after they’ve been treated for bowel cancer. What do you mean by health behaviours and what did you find out?

Health behaviours are the everyday choices people make that affect their health. In this study, we focused on 2 things:

1. healthy eating (more fruit, vegetables, whole grains and beans; and less fast food, red meat, processed meat, sugary drinks and alcohol)
2. physical activity

For people who’ve had bowel cancer, healthy behaviour may be associated with living longer, feeling better and having fewer problems like fatigue.

However, in previous studies, we found that many bowel cancer survivors don’t make big changes after treatment. Survivors are dealing with side-effects from the cancer or its treatment (such as gastrointestinal problems, fatigue or body image distress), which can make it hard to eat well and stay active.

Our study looked at what helps or gets in the way of healthy behaviour for people who have finished treatment for bowel cancer. We found:

Key takeaways:

• The CO21 CHALLENGE Trial found that a structured exercise programme after chemotherapy led to a 28% lower risk of cancer recurrence in colon cancer survivors compared with usual care.
• This is the first randomised controlled trial (RCT) to show that exercise directly improves survival in colon cancer patients. It confirms what observational studies have long suggested.
• The results were presented at a recent conference and made headline news. Experts say the CHALLENGE Trial marks a shift from viewing exercise as a “nice to have” to a “need to have” in cancer care.

Colon (part of the large bowel) cancer survivors who took part in a 3-year structured exercise programme had a 28% lower risk of cancer recurrence or a 2nd cancer. They also had a 37% lower risk of death compared with usual care.

These findings were shared at the 2025 Association of Clinical Oncology (ASCO) Annual Meeting. They were also published in the New England Journal of Medicine.

The ASCO Annual Meeting is the world’s largest oncology conference. It attracts more than 40,000 attendees from around the world. Every year, ASCO highlights the latest advancement in treatments. It also shares the directions that have the greatest potential for progress and patient impact.

Spotlight on exercise

The CO21 CHALLENGE Trial pulled back the curtain on a weapon that has been hiding in plain sight: physical activity. The results of the trial showed improvement in disease-free survival and overall survival in colon cancer survivors in the aerobic exercise intervention group. This trial is the first gold standard RCT to show what has long been indicated from observational studies. This is a big deal!

The impact of exercise on cancer outcomes has been a topic of great debate. Observational research has shown improvements in survival and quality of life linked to higher levels of physical activity. However, observational study designs are limited. They do not show cause and effect.

Plus, they are hard to implement in clinical settings due to concerns that the reported effects may not truly reflect the impact of exercise (and may be due to something else).

Our research

Over the past few years, World Cancer Research Fund International has done extensive reviews through its flagship Global Cancer Update Programme (CUP Global).

CUP Global includes partnerships with American Institute for Cancer Research, World Cancer Research Fund in the UK and Wereld Kanker Onderzoek Fonds in the Netherlands.

Our CUP Global reviews look at the extent to which diet, nutrition and physical activity impact people after a diagnosis of breast and colorectal cancers with regard to:

• cancer-specific mortality
• all-cause mortality
• risk of cancer recurrence
• health-related quality of life

An expert panel judged the strength of this CUP Global evidence. There were some limitations. Still, detailed recommendations were made to strengthen future research. One of the key recommendations was for well-conducted trials to look at the impact of nutrition or physical activity. The CHALLENGE trial is therefore very timely.

The CUP Global analysis was published in the International Journal of Cancer. It was cited several times in the CHALLENGE trial manuscript.

The CUP Global analysis compared highest with lowest levels of activity. We found that all-cause mortality was reduced by 23–40% depending on physical activity exposure.

Prof Richard Cooke

Prof Richard Cooke is interested in what motivates people to drink alcohol – he surveys people to find out how psychological variables such as the intention to drink, attitudes about drinking, and regret after drinking alcohol – can predict how much people consume.

“Most of my research has been done with young adults aged 18–30,” says Prof Cooke, “because they were traditionally seen as the group that drinks the most, but this has changed in the last decade. I’m now doing much more research with middle-aged people. I also do studies assessing awareness of drinking guidelines, comparing how young adults and policymakers talk about alcohol, and reviewing the effectiveness of alcohol interventions.”

‘We know it’s dangerous’

“I find alcohol consumption fascinating to study as drinking has high social approval even though we know it’s dangerous. This means that health messages about alcohol are trickier to create than smoking messages. Saying ‘Don’t smoke’ is quite acceptable; saying ‘Don’t drink alcohol’ is less so,” he says.

Prof Cooke has several theories about why alcohol remains so popular across cultures: “Alcohol is a social lubricant: it relaxes people, makes them feel more confident and more able to socialise, especially with strangers. It’s really tied to our psychology in many different, sometimes unexpected, ways.”

A former student of Prof Cooke, Dr Joel Crawford, did his doctorate degree on regret and drinking. He asked young people adults about the fear of missing out (Fomo). When they don’t drink, some people think they are missing out on an enjoyable experience, like missing a party because you have to work. Dr Crawford found that the young adults would rather experience alcohol harms, such as hangovers and feeling sick, than miss events that heavily included alcohol, saying “Fomo was more painful to them than a hangover!”

This study illustrates the social and emotional barriers people trying to drink less may encounter. “It’s the social acceptability of drinking in most situations that makes it a challenge to reduce; drinking is associated with celebrations – birthdays, weddings, getting a new job, becoming a parent– and commiserations – missing out on promotion or the death of a loved one. Alcohol is also linked to healthy activities, like ending a walk in the countryside with a drink in a pub.”

Drinking’s a habit

“At the individual level, drinking habits are an issue. People develop habits when they perform the same behaviour in a stable setting, like drinking every Friday night in the pub with your friends. Breaking this habit means unpicking your routines in ways that people often don’t want to do.”

However, based on current trends, there will be fewer people drinking into middle-age and later life: “This has the potential to dramatically change how we organise events,” says Prof Cooke, comparing it to the rise in the availability and acceptability of non-dairy alternatives to milk. “People will be asking for non-alcoholic drinks at parties, and maybe that will become as acceptable as asking for an alcoholic drink is now.”

Young people prefer to stay in control

We asked Prof Cooke about why there is a decline in young people drinking alcohol. “There are several theories about why this is happening. One is that young people spend a lot of time online, and they want to present the best possible version of themselves as someone who is in control. Studies of Facebook content show that people generally share positive alcohol content, rather than negative experiences.

“Another idea is that alcohol has become more expensive in the last decade or so, which has put young people off drinking. Finally, the rise of energy drinks may be part of the explanation too, especially for young people who like to play games online. Energy drinks, high in caffeine, are likely to aid video game performance. Alcohol is unlikely to do this.”

For people of any age trying to limit their alcohol, Prof Cooke recommends trying to understand the reasons why you drink. “Do you drink to be sociable, to enhance an evening out, to cope with negative emotions? Are there other ways you could meet those needs? Psychological interventions, such as feedback on drinking or setting goals to drink less, can also be effective ways to cut back.”

Prof Cooke’s latest research

Prof Cooke’s latest research is published in Drug and Alcohol Review. He says: “Our new paper shows that policymakers and drinkers talk about drinking in different ways. While policymakers focused on drinking behaviour, drinkers talked about how drinking made them feel different emotions: embarrassed, happy, guilty, sad. Policymakers need to construct policies to reflect the importance of emotions in drinkers’ narratives.”

> Read the paper: The language of alcohol: Similarities and differences in how drinkers and policymakers frame alcohol consumption

Alcohol and cancer: let’s talk

In the UK, alcohol is a major part of how many of us socialise, relax, and celebrate. But do we really know the risks we’re taking when we drink?

Our research shows that most people don’t know that drinking any amount of alcohol increases the risk of 7 types of cancer.

This Cancer Prevention Action Week, we want to spark a national conversation: with friends, family – and within government – about alcohol and cancer.

Research funded by World Cancer Research Fund has shown that people living with cancer who closely follow a sustainable and nutritious diet – the EAT-Lancet reference diet – have a lower risk of dying from cancer and from all causes.

This is the first study to look at the impact of the EAT-Lancet diet on people living with or beyond cancer – as opposed to the general population. Prof Sabine Rohrmann and her team at the University of Zurich, in collaboration with colleagues from another Swiss university, the UK and Austria, used UK Biobank data to see if closely following this diet – with its emphasis on eating a rich variety of plant foods – affected the risk of death for people with a cancer diagnosis at the time they were recruited for the study.

Studying more than 25,000 people with an average age of 60 years at recruitment, the researchers used dietary information collected in the UK Biobank to develop a score that reflected how closely participants followed the EAT-Lancet diet.

More support needed for people facing cancer

Of the 25,348 cancer survivors in the group studied, 4,781 people died during the study follow-up. Prof Rohrmann’s results showed modest links between closely following the diet and a lower risk of dying from cancer, and of dying from all causes. The researchers didn’t observe a link between the diet and dying from heart disease.

Almost 64% of the participants were female, and participants who followed the EAT-Lancet diet more closely were more likely to be female. However, this study confirmed previous evidence showing that people living with and beyond cancer do not tend to follow healthy diets after their diagnosis. This emphasises the need to help people form healthier habits and overcome the barriers to eating well, such as treatment side-effects affecting appetite and taste.

These findings highlight the importance of greater nutrition support and guidance for people facing cancer. Guidelines aimed at the general population are unlikely to consider the needs of people living with and beyond cancer. With a lack of evidence-based recommendations for this population, the gap can sometimes be filled by practices not supported by the science – such as excessive use of dietary supplements.

This evidence showing the benefits of the EAT-Lancet diet follows recent research by our Global Cancer Update Programme, which provided guidance for people with a breast or a bowel cancer diagnosis.

Researchers funded by World Cancer Research Fund have discovered that brisk walking is linked to a lower risk of 5 cancers:

• anal
• liver (hepatocellular carcinoma)
• small intestine
• thyroid
• lung

Using information stored in the UK Biobank – a large database of many different aspects of health – scientists explored the link between walking pace – slow, steady or brisk – and the risk of developing 28 types of cancer.

They confirmed that the link between brisk walking and a reduced risk of developing the 5 cancers was true, even after accounting for overall physical activity and total walking time.

Speeding up your walk could represent an easy, low-cost public health intervention to decrease cancer risk.

The paper, published in BMC Cancer, says:

“Adopting a brisk walking pace may represent a pragmatic target for public health interventions to decrease cancer risk, particularly in circumstances where increases in walking volume or frequency prove impractical.”

PhD student Michael Stein’s research was supported by funding from Prof Michael Leitzmann’s grant. This research was funded by World Cancer Research Fund as part of the WCRF International Regular Grant Programme.

> Read the full paper: Usual walking Pace and risk of 28 cancers– results from the UK biobank

> More on this grant

Despite the advances in cancer research over the past 40 years, including World Cancer Research Fund’s evidence on cancer prevention, and dramatic advances in cancer treatment, one question remains to be answered: why does one person get cancer when another, who lives a similar lifestyle, does not?

Experts estimate that up to 40% of cancer cases are preventable, if people didn’t smoke, avoided the sun, avoided alcohol, ate a healthy diet, maintained a healthy body weight and stayed physically active. But that doesn’t mean we can reduce our own risk of cancer by 40% if we follow this advice. It’s not easy to estimate an individual’s cancer risk because so many biological and genetic factors are also at play.

And that’s where large databases about our health can make a big difference. One of these is the UK Biobank, which contains details about the health – and increasingly, as the participants get older, the ill-health, of 500,000 people in the UK. The longevity of this data – not just at one point in a person’s life but repeatedly measured over a long period of time – helps us understand what influences cancer risk throughout someone’s life.

Heel bone density to house size

Since 2006, the UK Biobank has been collecting environmental, lifestyle and genetic information about the participants. For scientists, the size, range of information – from heel bone density to blood pressure to the size of their house – and duration of information collected is a gold mine.

It has been described as “the world’s most important health database” yet it’s not the only resource of this type. Another large database established as part of the European Prospective Investigation into Cancer and Nutrition (EPIC) study has grown into a massive project involving 10 countries, with 521,000 participants and data collected over more than 30 years.

Of the 30,000 registered researchers from 100 countries who have used data from the UK Biobank, some are funded by the World Cancer Research Fund network, and are using the data to investigate a range of cancer risk factors:

• Sleep, sleep patterns, and risk of prostate and endometrial cancer
• Fat tissue and advanced prostate cancer risk
• Social inequality and cancer risk
• Physical activity, sedentary behaviours, and cancer, cardiovascular disease and diabetes
• Plant-based diets
• Ultra-processed food
• Following our Cancer Prevention Recommendations
• Obesity and insulin
• Vegetarian diets
• Links between diabetes and cancer
• How many cancers are linked to obesity and physical activity?

Some of the things our scientists have found out using UK Biobank data include:

• Physical activity across the day – with a peak early in the morning and late in the evening – linked to lower risk of colorectal cancer
• Ultra-processed food increases cancer risk
• Following our Cancer Prevention Recommendations reduces the risk of all cancers

The UK Biobank allows researchers around the world to look at biological and medical data and “supports a diverse range of research intended to improve the prevention, diagnosis and treatment of illness, and the promotion of health throughout society”.

And it’s not easy to get hold of such large amounts of data. It’s hard to get half a million people to consent to sharing their personal data in this way, and even harder to get them to keep filling in surveys and undergoing procedures over many years. This type of research can only be done with people’s support and willingness to consent, and without it, finding ways to prevent and treat diseases such as cancer will be so much harder.

The wealth of data the UK Biobank contains could have drastic implications for cancer research, perhaps even finally helping realise World Cancer Research Fund’s ambition of living in a world where no one dies of a preventable cancer.

What do our grant holders say about UK Biobank?

Eating a wide variety of food may reduce the risk of gastrointestinal cancers, according to research funded by the World Cancer Research Fund network* and published in the European Journal of Cancer.

Little is known about how eating a wide variety of food species, also known as food biodiversity, may benefit our health or affect our cancer risk. Food species refer to a distinct type of plant or animal, such as wheat, chicken, or salmon. For example, salmon, mackerel, and tuna are all separate food species, even though they share some biological traits and belong to the same food group. Similarly, rocket, lettuce and spinach count as separate food species, even though they are all leafy green vegetables. However, chicken and a chicken’s egg belong to the same food species even though they are different types of food.

This study is the first to examine how the number of different food types consumed, measured as Dietary Species Richness (the number of species an individual consumes per year) affects the risk of the following gastrointestinal cancers:

• Oesophagus
• Throat
• Stomach
• Bowel
• Colon
• Rectum
• Gallbladder
• Pancreas
• Liver

The study followed 450,111 cancer-free adults in 9 European countries from the European Prospective Investigation into Cancer and Nutrition cohort for 14 years. The researchers, from the International Agency for Research on Cancer, found that individuals with the most diverse diets, by including more food species in their diet, had a 23% lower risk of developing gastrointestinal cancers compared with those with the least variety. The risk decreased by 6% for every 10 extra species per year added to their diet. People can do this by including more variety in the types of fruit and vegetables they eat, for example, choosing to eat local and seasonal fruit and vegetables of different colours.

Food biodiversity includes eating different types of food that provide the necessary nutrients for maintaining health. Investigating food biodiversity is important because it has the potential to benefit public health and sustainable food systems.

Dr Helen Croker, our Assistant Director of Research and Policy, said: “Diets have become more limited in the types of foods eaten and they are often high in fat, sugar and salt. However, for cancer prevention, it’s important to eat a healthy, balanced and varied diet with plenty of wholegrains, pulses, vegetables and fruit.”

Another study from this grant looked at how food biodiversity is measured. Methods such as Hill numbers estimate the number of species, but it wasn’t clear whether these numbers could be compared across different study settings.

The findings showed that Dietary Species Richness is the most feasible way to measure and evaluate food biodiversity across various contexts, and considering high-, middle- and low-income countries. Regardless of which Hill number was used, however, all measures indicated that greater food biodiversity was associated with better micronutrient sufficiency and with lower rates of all-cause mortality, this latter association yet being strongest for Dietary Species Richness.

This grant was funded by Wereld Kanker Onderzoek Fonds based in the Netherlands, as part of the World Cancer Research Fund International network.

> More on this grant: Will a balanced diet also save the planet?

Achieving a balanced combination of exercise and controlling our waistline is far more effective in reducing our risk of cancer than doing just one or the other, according to a study funded by World Cancer Research Fund.

In the world’s first study looking at the effectiveness of combining these measures, we found that only doing one is not enough to lower our risk of cancer. The study, which looked at more than 300,000 people, found that:

• People not meeting World Health Organization (WHO) guidelines on waist circumference are at 11% greater risk, even if they are physically active.
• People not meeting WHO guidelines for physical exercise are at 4% greater risk, even if “abdominally lean” (ie they have a smaller waist).
• Achieving neither means a 15% greater risk.

The study – WHO guidelines on waist circumference and physical activity and their joint association with cancer risk (Lead researcher: Prof Michael Leitzmann, University of Regensburg) – was published in the British Journal of Sports Medicine.