Bowel cancer study seeks 250,000 UK adults as cases rise among younger people

PROSPECT-UK is seeking 250,000 UK adults for research into the increase in bowel cancer diagnoses among people under 50.

Researchers from King’s College London and ZOE will follow volunteers over time, examining information about diet, lifestyle, environment and health. The unusually large recruitment target reflects a practical research challenge: bowel cancer is becoming more common among younger adults, but early-onset disease remains relatively uncommon.

Cases of early-onset bowel cancer have increased substantially worldwide since 1990, and the UK is reported to have one of the fastest-rising rates. The change has created a significant Health research question, although its precise cause has not been established.

PROSPECT-UK will look for patterns across a large population rather than start from a single presumed explanation. It will consider factors that may overlap or change over time, including participants’ food, daily habits, surroundings and wider health. This design means the project can examine several possible relationships while avoiding the assumption that any one factor is responsible.

Why the study needs such a large group

Scale is central to the project. Researchers need to observe enough people for long enough to compare how different characteristics and exposures correspond with later health outcomes. Because bowel cancer remains uncommon among younger adults, a smaller cohort would offer less scope for examining differences within that population.

Dr Rosiered-Brownson Smith, a research associate on the study at King’s College London, said the continuing rarity of early-onset bowel cancer means a large body of participants is required to investigate the rise. The scale is intended to provide enough information for researchers to distinguish patterns that could otherwise be difficult to detect.

The target of 250,000 participants is not an estimate of the number who will receive a cancer diagnosis. It is the planned size of the group whose information will be followed. Researchers aim to identify associations that warrant closer investigation, but the project cannot promise in advance that it will establish one definitive explanation for the increase.

The Independent’s report on PROSPECT-UK says participants’ dietary habits and lifestyle patterns will be monitored over an extended period. Yahoo News UK’s account of the bowel cancer study describes Britain as one of the countries where the rate among younger adults is rising particularly quickly.

Large cohort studies are also used to examine how health develops at other stages of life. A separate UK study following 30,000 children similarly relies on repeated information from a substantial group, although its population and research questions are different from those of PROSPECT-UK.

The UK project forms part of a global investigation

King’s College London and ZOE lead PROSPECT-UK, which will also contribute to Team PROSPECT. That wider international effort is investigating the increase in early-onset bowel cancer across different countries and populations.

The global programme combines work from several research disciplines. This allows findings from the UK cohort to be considered alongside patterns in other national settings, rather than treating the British rise as an isolated development.

Team PROSPECT is funded through Cancer Grand Challenges by Cancer Research UK, the US National Cancer Institute, The Bowelbabe Fund for Cancer Research UK and the French National Cancer Institute. Mirage News’ report on the recruitment programme identifies those funders and explains how PROSPECT-UK contributes to the international work.

The international structure is relevant because the increase is not confined to Britain. Comparing countries and populations could help researchers examine where trends coincide and where they diverge. The UK project supplies a large national cohort for that broader effort, while retaining a detailed focus on participants’ lives and health over time.

Professor Sarah Berry, the PROSPECT-UK chief investigator and a professor of nutritional sciences at King’s College London, has said that diets, lifestyles and environments have altered markedly across recent generations. Researchers do not yet know which changes might raise bowel cancer risk or which could reduce it, making extensive long-term information necessary to investigate early-onset disease.

Those areas define what the project will examine, not conclusions about causation. Information from questionnaires will be considered alongside health records so that researchers can study whether reported experiences or habits correspond with diagnoses recorded later.

What volunteers will be asked to do

For most participants, involvement will centre on information provided online and consent to connect it with existing medical data. Biological samples and detailed food records will be requested only from a small subgroup, rather than from everyone in the 250,000-person cohort.

• Complete online questionnaires: volunteers will provide information about their diet, lifestyle, environment, health and other relevant matters.
• Remain in the study over time: long-term follow-up will allow researchers to compare information reported by participants with subsequent health outcomes.
• Consider health-record linkage: participants will be asked to consent to their study information being connected with electronic health records.
• Join more detailed work if invited: a small subgroup will be asked to keep fuller diet diaries and provide blood and stool samples.

Health-record linkage is a central feature because it enables researchers to study future diagnoses alongside information collected directly from volunteers. The additional work with the smaller subgroup will provide more detailed dietary information and biological samples without placing those requirements on the entire cohort.

The questionnaires cover several parts of everyday life because the reason for the rise may be complex rather than attributable to one isolated change. Following the same people over time also provides a different kind of information from a one-off survey, as it allows reported factors and later health events to be examined in sequence.

Any relationship detected between an exposure, behaviour and health outcome will still require careful interpretation. An association would not by itself prove that one factor caused bowel cancer. PROSPECT-UK is designed to create the large, long-term body of information needed to investigate the increase more closely, while the reason younger adults are receiving more diagnoses remains unresolved.

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