Clinical trials

If you're interested in taking part in breast cancer research, you can learn more about clinical trials here, including what they are, the benefits and potential drawbacks, and how to take part.

1. What are clinical trials?

Clinical trials are research studies involving people. They aim to improve diagnosis, treatment, side effects and quality of life.

For people with breast cancer, clinical trials might include:  

  • Looking at ways to reduce the likelihood of getting breast cancer
  • Improving diagnostic methods (such as breast screening)
  • Testing new cancer drugs to find out more about them and any side effects
  • Testing new treatments to see if they work better than current treatments
  • Testing current treatments in different ways to reduce side effects
  • Finding new ways to combine treatments to see if they work better
  • Looking at the effect a treatment has on everyday life (quality of life)
  • Looking at whether additional psychological support makes a difference

Find out more about clinical trials for breast cancer and the types of clinical trial you may be offered on the Cancer Research UK website.

2. Benefits and drawbacks of taking part in a clinical trial

Benefits of taking part in a clinical trial might include:

  • Being one of the first people to benefit from a new treatment
  • Having the opportunity to help others and improve breast cancer treatment
  • Having extra appointments and tests which may mean you feel more supported and closely monitored

Drawbacks of taking part in a clinical trial might include:

  • Unexpected side effects from a new treatment or an existing treatment given in a different way
  • The new treatment not being any more effective than the standard treatment
  • The new treatment being effective for some, but not for you
  • Extra hospital visits that may not be convenient or desirable
  • Extra tests that make you feel more nervous
  • Not receiving the new treatment if you are part of the standard treatment (control) group of the trial

3. How are clinical trials approved?

New cancer drugs or treatments are tested and researched thoroughly before they are used in people.

Before a clinical trial begins it has to be approved by a group of independent scientists and then by a research ethics committee. The committee make sure the trial is safe and in the best interest of patients. They are made up of healthcare professionals as well as people without a medical background.

There are other safeguards in place for people taking part in trials. For example:

  • The trial plan (protocol) must be judged safe and ethical by the ethics committee before it can go ahead
  • The researchers must tell the ethics committee if there are any unexpected side effects
  • The ethics committee can stop the trial at any time if they have any concerns
  • Arrangements must be in place to pay compensation if anything goes wrong
  • You must be told any benefits and risks before you agree to take part
  • You can stop taking part in the trial at any time

If during a trial it becomes clear that one treatment is much better or worse than the other, or a treatment is causing severe side effects, the trial will be stopped and eligible patients will be offered the most effective treatment.

4. Phases of clinical trials

Clinical trials testing new treatments are divided into different phases. Phases 0 to 2 usually look at whether a drug is safe and any side effects it causes. Phases 3 and 4 aim to test whether a new treatment is better than existing treatments.

Phase 4 trials are carried out after a drug has been licensed (this link takes you to the Cancer Research UK website). They look at drugs which are already available for doctors to prescribe rather than new drugs that are being developed.

You may be asked to join a phase 0 trial, although most trials involving cancer patients start at phase 1.

Find out more about the different phases of clinical trials on the Cancer Research UK website.

5. Can I take part in a clinical trial?

Your specialist may offer you the opportunity to take part in a clinical trial if you’re eligible. Or you could ask them about a trial you would like to take part in, or if there are any others that may be suitable for you. 

If you’re interested in taking part in a trial, talk it through with your specialist. They’ll be aware of the main breast cancer trials that are in progress and which ones are happening in your area. They can advise you according to your situation.

Every clinical trial has strict guidelines about who can be involved. For example, you might need to have a certain level of fitness to take part.

If you’re not able to take part in a particular trial, you may be disappointed. However, your treatment team will continue to support you and offer the best treatment and care available.

If you’ve been asked to take part

Deciding whether to take part in a clinical trial can be difficult and sometimes feel overwhelming.

If you’ve been asked to take part in a trial, your specialist or a research nurse will discuss exactly what’s involved with you. You should be given written information with all the details of the trial. This should include information about the type of trial, the possible benefits and risks, and whether extra tests or hospital appointments are needed. All information about participants is kept confidential.

You should be given time to make a decision about whether to take part.

It is important you understand what is involved before you give consent to take part. Ask your specialist or the research nurse any questions you may have. If you don’t feel that taking part in a trial is the right option for you, you can decline without giving a reason.

Questions to ask

You might like to ask some of the following questions if they’re not already covered in the information given to you by the trial team.

Some people find it useful to write a list of questions they want to ask and take it to their appointment. You can print off our list of suggested questions to take with you.


Giving consent

Once the details of the trial have been explained, you should be given written information and time to think it over and make your decision.

If you decide to take part in a clinical trial, you will be asked to sign a form saying that you agree to take part and understand what is involved. This is called giving informed consent. However, this does not commit you in any way and you can withdraw from the trial at any time if you change your mind.

If you’re thinking of leaving a trial you can do so at any time and you do not have to give a reason. Stopping taking part will not affect any future care you receive. If you want to leave a trial you can discuss this with your specialist or research nurse.

You cannot be entered into a clinical trial without your knowledge and without giving your consent.

Blood and tissue samples

You will have blood and tissue samples taken during your diagnosis and treatment. For example you may have tissue removed during a biopsy.

Your specialist may ask for your consent to use your samples for research. These samples can be looked at to:

  • Find out more about different types of breast cancers
  • Develop new breast cancer treatments or drugs

6. Where can I find out more about clinical trials?

You can find out more about clinical trials on the NHS website. Cancer Research UK also has information about clinical trials for breast cancer.

For current breast cancer clinical trials, you can search Cancer Research UK's online database or the Be Part of Research website.

You’ll find research projects and clinical trial opportunities on our forum.

People living with secondary breast cancer can find clinical trials through Make 2nds Count's Patient Trials Advocate Service. The service matches people living with secondary breast cancer with a nurse who can talk you through the process and help you find clinical trials. 

You could also ask a member of your treatment team if they know about any clinical trials that you might be able to take part in.

7. Further support

Deciding whether to take part in a clinical trial can be overwhelming and you may feel unsure about the right option for you.

Speak to people who have been through similar experiences on our confidential forum. Our Someone Like Me service - please see below - can put you in touch with someone who has had a similar experience, so you can talk through your worries and share experiences over the phone or by email.

You can listen to other people’s experiences of clinical trials on the Healthtalk website.

If you would like any further information and support about clinical trials for breast cancer or just want to talk things through, you can speak to one of our experts by calling our free helpline, below.

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Quality assurance

Last reviewed in November 2021. The next planned review begins in November 2023.

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