1. What are clinical trials?
2. Clinical trials for breast cancer
3. Are clinical trials safe?
4. Types of clinical trials
5. Different stages of clinical trials (trial phases)
6. Can I take part in a clinical trial?
7. What are the benefits and drawbacks of taking part in a clinical trial?
8. When will the results of the trial be published?

1. What are clinical trials?

Clinical trials are research studies that aim to find new or better treatments. They may also look at using existing treatments in different ways.

Taking part in a clinical trial may give you access to a new treatment or a new way of receiving treatment that may otherwise not be available to you.

New drugs go through several phases of testing on people in clinical trials before they can be routinely used to treat patients.

All clinical trials are designed to make sure everyone receives at least the quality of treatment that would have been recommended if they hadn’t been taking part in the trial.

2. Clinical trials for breast cancer

There are many types of clinical trials looking at different aspects of breast cancer, such as:

  • ways to reduce the likelihood of getting breast cancer
  • diagnosing breast cancer (such as different screening methods)
  • treating breast cancer (such as new drug combinations and new ways of giving treatment)
  • non-drug treatments or support (such as counselling, diet, physical activity and complementary therapies)

You might also hear about research studies looking at the non-medical effects of treatment, such as quality of life and attitudes towards treatments. People taking part in these trials may be asked to fill out a survey or questionnaire.

3. Are clinical trials safe?

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, first by a group of independent scientists and then by a research ethics committee. These committees are often based at local hospitals and are made up of healthcare professionals and lay people.

There are other safeguards in place for patients 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

4. Types of clinical trials

Randomised controlled trials (RCTs)

These aim to compare a new treatment with the best current or standard treatment to see if the new treatment is better.

People who take part in RCTs are put into groups that are usually the same size. The groups then have different treatment. The selection of the group you are in is usually done by a computer and is called randomisation.

It’s important that the groups of people are as similar as possible. This is because the researchers need to be sure that if one group does better than the other it’s because of the treatment, and not because the people in the groups are different from each other in some way. The only way to make sure that the groups are as similar as possible is by allocating people to a group at random.

Neither you, your specialist team nor the research team can choose which treatment you’ll receive. You may not have the new treatment, in which case you’ll be part of the ‘control’ group, which receives a standard treatment. This is usually the treatment you would receive if you were not in the trial.

Being in the control group and not receiving the new treatment can be difficult for some people to accept. However, these patients are vital to the trial and will still be receiving the best current treatment

Placebos and double blind trials

In some trials a new drug is compared with a placebo. A placebo has no active ingredients but is made to look exactly like the drug being tested.

A placebo is only used when patients wouldn’t have had any other treatment if they weren’t in the trial. This means they don’t miss out on something, because there’s no other standard treatment available.

Using a placebo means the effect of the new drug can be measured much more accurately. This is because sometimes people appear to do better just because they are involved in a trial, even if they are not given the new drug. It’s not known why this occurs. It may be because people taking a placebo are monitored more closely or because they or their doctor are optimistic about the benefit of the new treatment.

The patient will not know whether they are receiving the active treatment or the placebo. Usually the doctor doesn’t  know either – this is known as a double blind trial. This helps to reduce bias and means the trial results should be more accurate. If necessary, doctors can find out from the trial organisers whether or not a patient is getting the new treatment – for example if there are unexpected side effects.

5. Different stages of clinical trials (trial phases)

Each new drug undergoes rigorous testing before it can be widely used. First it is tested in the laboratory. If it shows promise, it then has to go through several phases of testing on people in clinical trials before doctors are allowed to use it routinely to treat patients.

Stories in the media sometimes describe a new drug as ‘a major breakthrough’ when it’s still at the stage of laboratory testing. In fact, it may still be several years before the results from tests on patients in clinical trials become known, which can be disappointing and frustrating for people who see a new drug as a source of hope.

There are various stages at which you may be asked to join a clinical trial. These are called trial phases.

Phase 0 trials

You may be asked to join a phase 0 trial, although most trials involving cancer patients start at phase 1. Phase 0 trials aim to find out whether a drug behaves in the way researchers expect it to.

Phase 0 trials usually involve a small number of people who are given a very low dose of the drug. This drug will not treat the cancer because the dose is too small.

Phase 0 trials aim to find out:

  • if the drug reaches the cancer
  • whether there are any side effects
  • whether cancer cells in the body respond to the drug

You can expect extra scans, blood tests and biopsies to help the researchers find out more about the drug being used in the trial.

Phase 1 trials

You’re more likely to be asked to join a phase 1 trial if you have secondary breast cancer and have had all the standard treatment available. People with different types of cancer sometimes take part in the same phase 1 trial.

Phase 1 trials aim to find out:

  • how often and what dose of the drug can be given safely without causing serious side effects
  • whether the treatment has any effect on your cancer

Phase 1 trials do not look at the overall effectiveness of a treatment. However, there is a small chance that your cancer may respond to the drug, and any side effects of the drug are carefully recorded. You may also have blood tests to see how your body is coping with the drug.

Phase 2 trials

Some, but not all, treatments tested in a phase 1 trial are then looked at in a phase 2 trial. These include large numbers of patients who may have the same or different types of cancer. 

Phase 2 trials aim to find out:

  • which types of cancer the drug is best suited for
  • more about the side effects and how to manage them
  • what the best dose is

If the new treatment works well enough, it will usually be tested in a phase 3 trial.

Phase 3 trials

These are larger trials that aim to compare the new treatment with the best current or standard treatment to see if the new treatment is better. They also look at different ways of giving standard treatments.

Most phase 3 studies are randomised controlled trials (RCTs).

Their size varies but they can involve several thousand patients from many cancer centres in different countries.

Phase 4 trials

These trials are carried out after a drug has been licensed. They aim to collect information about the side effects, safety, long-term risks and benefits of the drug. Phase 4 trials look at treatments that are already available for doctors to prescribe, rather than new ones that are still being developed.

Most trials will also include a quality of life study. This collects information about the impact of the treatment on daily life and any side effects.

6. Can I take part in a clinical trial?

You may have heard about a clinical trial that you would like to take part in, or your doctors may have offered you the opportunity to take part in a trial if you’re eligible. 

Whatever your situation, deciding what to do can be very difficult, particularly as information about clinical trials can be confusing. It may also be hard to absorb extra information when you have already been given a lot of information about treatments.

If you’re interested in taking part in a trial, talk it through with your cancer specialist, who is most familiar with your medical history. They’ll be aware of the major 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. All information about participants is kept confidential.

If you’re not able to take part in a particular trial, you may be disappointed or feel as if there are limited options for the future. Your specialist team will continue to support you and offer the best treatment and care available.

If you’ve been asked to take part

If you’ve been asked to take part in a trial, your specialist or a research nurse will discuss with you exactly what’s involved. This should include the type of treatment you might receive, what possible benefits or side effects you might expect, or what extra tests or hospital appointments you may need. You will also be told which stage (phase) of the trial you will be taking part in.

You will usually be given an information pack with all the details of the trial, and you’ll have some time to make a decision about whether to take part.

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. Here are some suggestions:

  • How many people are in the trial?
  • How long will I be in the trial?
  • If I have to have extra tests what are these likely to be?
  • Will I have to have extra hospital visits? If so, will the trial pay for my travel to and from hospital?
  • Is the data collected about me kept confidential?
  • Who will I be able to contact if the research nurse is not available?
  • Will I need to donate blood or tissue samples, and if so, is this an optional part of the trial?
  • Will there be a questionnaire or diary to fill in?
  • How might the treatment affect me physically and emotionally?
  • What treatment will I receive if I don’t enter the trial?
  • Will I get to know the results?
  • How will being on this trial affect my outcome?
  • Will I be treated at the same hospital or will I have to attend a different clinic?

Giving consent

Once the details 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 still 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 won’t 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.

Consent for using your tissue

In recent years, researchers have developed a greater understanding of cancer cell biology and have recognised the importance of understanding how different treatments might affect how cancer behaves. To help with this you may be asked to give your consent for tissue removed during a biopsy or surgery to be used for research.

During the trial

The trial will be overseen by an independent committee including breast cancer specialists and statisticians (people who interpret statistics).

If at any time during the trial it becomes clear that one treatment is much better or safer than the other, the trial will be stopped and eligible patients will be offered the most effective treatment.

You will usually be given a named person (normally the research nurse) to contact if you have any problems or are concerned about side effects. Your specialist should also tell your GP that you are taking part in a trial.

Finding a clinical trial

If you want to find out more about current breast cancer clinical trials, you can search Cancer Research UK's online database of clinical trials, the Be Part of Research website or the NHS website.

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

7. What are the 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
  • being seen more frequently at the hospital than people not in the trial (as extra tests may be needed)
  • benefiting even if you are having the standard treatment as you may have extra tests and therefore be monitored more closely

Drawbacks of taking part in a clinical trial might include:

  • unexpected side effects from the new treatment
  • 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 or preoccupied with your breast cancer
  • not receiving the new treatment if you are part of the standard treatment (control) group

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

8. When will the results of the trial be published?

The time clinical trials take to complete and publish their results varies from a few months to several years, depending on what the trials are looking at. For example, a trial studying the long-term side effects of radiotherapy may collect information over a number of years before the results are published.

You can ask your research nurse for the results of the trial when they are released. The results are also usually published by specialist medical organisations such as:

Last reviewed: December 2018
Next planned review begins 2021

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