Clinical Trials — What They Are, What You're Entitled to Ask, and Why the System Has Been Keeping Quiet

There is a conversation that should be happening in oncology appointments across the UK and largely isn't.

Not because clinicians don't care. But because a system under sustained pressure has developed habits around clinical trials that serve the system's convenience rather than your interests — and most patients don't know enough to push back on.

The habit looks like this. You come in. You are seen. Your treatment is discussed. And somewhere in a database you were never told about, there may be a trial you could have been offered — a study testing a new treatment, sometimes involving drugs not yet available outside a research setting, sometimes involving closer monitoring and additional support. It might not apply to you. But the conversation about whether it does — and what it would mean — didn't happen. And you left without knowing it was ever there.

Between 2022 and 2025, the number of patients recruited into UK industry clinical trials fell by 25 per cent. Recruitment is now at its lowest level since 2017/18. The government has committed to quadrupling commercial trial participation by 2027. It is not on track.

You are reading this because you or someone you love has been through cancer treatment. You deserved that conversation at the time. This chapter is it.

What a trial actually is — and why being offered one is usually good news

Let's start here, because the most common reason people hesitate is the most wrong one.

Being offered a clinical trial does not mean your treatment has run out. It does not mean you are being used as an experiment. It does not mean your oncologist is uncertain about your care. For most cancer patients, being offered a trial is a sign of exactly the opposite — that you are being cared for by a team who are engaged with the latest research, and that there is something being evaluated that might be better than the current standard.

Every cancer treatment that is standard today was a clinical trial at some point. The chemotherapy regime, the targeted therapy, the immunotherapy — these became available because someone ran a trial and established that they worked. The trials running now are testing the treatments that will be standard in five or ten years. Joining a trial is not stepping outside the healthcare system. It is being at the front of it.

There are different phases and they mean different things. Phase 1 is early — primarily testing whether a drug is safe and at what dose. These trials typically involve small numbers of patients, often people who have exhausted standard options, and joining one is a genuinely different kind of decision. Phase 2 tests whether a treatment appears to work. Phase 3 — the most common type a cancer patient is likely to be offered — compares a new treatment or combination against the current best standard. If you join a phase 3 trial, you will receive either the new treatment or the best current standard care. You will not receive less than you would outside the trial.

You are entitled to say no. Saying no cannot affect the quality of your standard care in any way. This is not a courtesy statement. It is a legal protection. Your team cannot treat you differently because you declined.

The numbers on the consent form — what they mean in plain English

Here is the situation this section is written for.

You are in a consultation. Someone has handed you a document. It is several pages long. It contains words like hazard ratio, confidence interval, relative risk reduction, p-value. The clinical team are waiting. You are frightened and you have never heard most of these terms before in your life. And you are being asked to make a decision.

This section exists so that you can ask the right questions before you sign anything. Not to turn you into a statistician. To give you the three questions that cut through the numbers to the thing you actually need to know.

**The first thing to understand is the difference between relative risk and absolute benefit.** This is the most important distinction in cancer statistics and the one that most misleads people — not through dishonesty, but through the gap between what the number sounds like and what it actually means.

Here is an example. A treatment reduces the risk of recurrence by 18 per cent. That sounds significant. But 18 per cent of what? If the risk of recurrence without treatment is 10 per cent, and treatment reduces it to 8 per cent — that is an 18 per cent relative risk reduction. It is also a 2 per cent absolute benefit. Two fewer people in every hundred experience recurrence. Both numbers are true. One sounds considerably more impressive than the other.

The number that tells you what actually happens in the room — to real people, in real numbers — is the absolute benefit. Before you agree to any treatment, before you consent to any trial, ask this: what is the absolute benefit? Not the percentage reduction. The actual number of people in a hundred, or a thousand, who are materially better off. That number is yours to have.

**The second thing is the hazard ratio.** A hazard ratio is the rate at which something — recurrence, death, progression — happens in one group compared to another. An HR of 0.82 means the treatment group experienced the event at 82 per cent of the rate of the comparison group. That sounds like an 18 per cent improvement. The problem is that a hazard ratio tells you nothing about the size of the effect in human terms. You need the absolute numbers alongside it.

If someone gives you a hazard ratio without context, the question is: what does this mean in absolute terms? How many more people in a hundred would be expected to be alive — or disease-free — after this treatment? That question cannot be brushed aside. It is the question your consent depends on.

**The third thing is what doesn't count as a good answer.** A p-value below 0.05 means a result is statistically significant — there is less than a 5 per cent chance it happened by chance. What it does not mean is that the effect is large, or that it matters in everyday terms, or that the benefits outweigh the side effects for you specifically. Statistically significant is not the same as clinically meaningful. When you hear that a trial result is statistically significant, the follow-up is always: and what was the absolute benefit?

The question underneath all of this is this: what does this mean for my life? Not my hazard ratio. My life. Will I live longer? Will I be able to care for my family? Will I feel well enough to work? How will I feel during treatment? What happens if it doesn't work? These questions are yours to ask. A good clinical team will answer them directly. If the answers are not coming clearly, ask more directly: I need to understand what this means for me, specifically, in everyday terms. Can you help me with that?

Your right to ask — and the sentence that opens the door

The NHS Constitution gives patients in England the right to be offered participation in research that is relevant to their care. This is a stated patient right. Whether it is consistently honoured is a different question — the evidence says it is not — but knowing it exists changes what you are entitled to say.

The question to ask at any oncology appointment is this: Are there any clinical trials currently open that I might be eligible for, given my diagnosis and where I am in my treatment?

That is the whole sentence. It takes ten seconds. It cannot be held against you. It sometimes produces an answer that changes what is available to you.

The reason to ask rather than wait is that the system frequently doesn't raise it unprompted. Clinicians operating under significant time pressure, managing complex caseloads, default to the established treatment pathway because it is what the appointment structure accommodates. The trial conversation takes longer, involves paperwork, requires a referral process. These are not reasons for the conversation not to happen. They are reasons it often doesn't. Knowing that, and asking the question yourself, is the practical response.

If you are told there are no trials currently relevant to you, that is a complete and valid answer. But it is the answer to have confirmed, not assumed.

A woman I want you to picture

She is fifty-three. She has been through treatment for ovarian cancer at a large NHS trust. Her care has been good. Her clinical team have been attentive. At no point in eighteen months of treatment and follow-up has anyone raised the subject of clinical trials.

There are, at that trust, three trials currently open for patients with her diagnosis at her stage. She is potentially eligible for at least one of them. The trial team is struggling to recruit. The patients who are being referred tend to be from the less deprived areas of the catchment, tend to speak English as a first language, and are disproportionately White. A 2024 study published in the journal Cancers examining ovarian cancer trials in London found exactly this pattern — trial participants were predominantly White, English-speaking, and from less deprived areas, and the disparity could not be explained by eligibility criteria alone.

She never knew to ask. Nobody told her she had the right to. She will spend the next ten years wondering whether the treatment she received was the best available option.

That woman is not an exceptional case. She is what the data describes as the norm for too many patients.

Who is least likely to be offered a trial — and why it matters

The clinical trial access problem is not evenly distributed. UK research published in the British Journal of Cancer in 2024, examining referrals to Experimental Cancer Medicine Centres in Newcastle and Manchester, found significant inequalities in who got referred. Patients from deprived areas, patients from ethnic minority backgrounds, and patients who lived furthest from the trial centres were all less likely to be referred — not because they were ineligible, but because the conversation was less likely to happen.

A 2024 pilot by the NHS Race and Health Observatory on breast cancer trial diversity identified multiple barriers — communication, cultural mistrust, language, and information provision — that were not being addressed. Blood Cancer UK's active project on clinical trial access for Black and Pakistani communities exists precisely because certain blood cancers are more common in these communities and their members are substantially underrepresented in the trials that determine how those cancers are treated.

This matters for two reasons. The immediate one: if you are in one of these groups, the trial that might help you is less likely to be put in front of you. The long-term one: the treatments that become standard in ten years are shaped by the evidence from the trials running now. If certain communities are not in those trials, the treatments that emerge are less well calibrated for those communities. The underrepresentation today produces the health inequality tomorrow.

If you are from a community that is statistically less likely to be asked — if you are from a Black, Asian, or ethnic minority background, if you are older, if English is not your first language, if you live in a deprived area — you have every right to raise the question yourself. The question is the same: are there any trials currently open that I might be eligible for? Macmillan's Support Line on 0808 808 00 00 can also help you understand what exists and how to ask about access if the conversation is not being started by your team.

How to find trials yourself

You do not have to wait for your clinical team to raise this. You can look, and the tools to do it are free and designed for patients rather than specialists.

The Cancer Research UK Find a Clinical Trial database at cancerresearchuk.org/find-a-clinical-trial is searchable by cancer type, treatment, stage, and location. It lists trials currently recruiting in the UK, explains in plain language what each involves, and tells you which hospitals are participating. If you find something that looks relevant, you take it to your clinical team and ask: could I be eligible for this? You do not self-enrol. You raise it as a question.

Be Part of Research at bepartofresearch.nihr.ac.uk is a national NHS service that matches people with research studies. As of January 2026 it is being integrated into the NHS App under the National Cancer Plan, allowing patients to search trials and ask to be contacted. The integration is in progress — the service operates now.

Cancer Research UK's information nurses can search the database for you if navigating it yourself feels like too much. Call 0808 800 40 40, Monday to Friday, 9am to 5pm.

Blood Cancer UK at bloodcancer.org.uk has specific information on blood cancer trials and specific guidance on access for communities where blood cancers are more prevalent and trial participation has historically been lower.

Informed consent — what it actually means and what you are entitled to

Informed consent is not a formality. It is a legal and ethical protection — the requirement that you understand what you are agreeing to before you agree.

Before joining any trial you must receive a patient information sheet explaining what participation involves, what the potential benefits and risks are, what happens if you withdraw, and who to contact with questions. You are entitled to take this document away, read it at home, show it to someone you trust, and take as long as you reasonably need to decide. Signing the consent form at the same appointment where you first heard about the trial is not required. If that feels like what is being expected, say: I'd like to take this home and think about it first. That is a completely normal and acceptable request.

You can withdraw at any time without giving a reason. Withdrawing cannot affect your standard care.

If you have questions during the trial — about what is happening, about your results, about whether anything has changed — you are entitled to ask them and receive clear answers.

What to do at your next appointment

If you are at a decision point in your treatment — starting a new treatment line, discussing options following a recurrence, or entering a new phase of care — ask about clinical trial eligibility before the treatment decision is finalised. Some trials require that you have not yet started a specific treatment and the window for eligibility can close once treatment begins. Ask before, not after.

• Cancer Research UK Find a Clinical Trial (searchable by cancer type, UK trials currently recruiting) — cancerresearchuk.org/find-a-clinical-trial
• Cancer Research UK information nurses (will search the database for you): 0808 800 40 40, Monday to Friday 9am–5pm
• Be Part of Research (national NHS trials matching service) — bepartofresearch.nihr.ac.uk
• Blood Cancer UK (information on blood cancer trials, access for Black and Pakistani communities) — bloodcancer.org.uk
• Macmillan Support Line (free, can advise on trial access and referral, 8am–8pm seven days): 0808 808 00 00