1. What are clinical trials?
2. Different types of clinical trial
3. Taking part in a clinical trial
4. Benefits and drawbacks of taking part in clinical trials
5. Phases of clinical trials

1. What are clinical trials?

Clinical trials are research studies that look at different aspects of patient care. They are a routine part of the work of specialist breast cancer centres.

The results of past clinical trials help doctors give you advice on your current treatment.

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 currently in progress and which ones are happening in your area. They can advise you according to your situation.

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2. Different types of clinical trial

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

  • ways to reduce the likelihood of getting breast cancer
  • diagnosing breast cancer
  • treating breast cancer
  • the effects a particular treatment has on quality of life
  • non-drug treatments or support, such as counselling, diet, physical activity or complementary therapies

Many breast cancer trials look at new treatments or different ways of giving existing treatment, such as surgical techniques, chemotherapy or radiotherapy.

New cancer drugs or treatments are tested and researched thoroughly. Before a 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 non-medical people.

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

Randomised controlled trials

A randomised controlled trial (RCT) is a type of trial where the people taking part are randomly allocated to different treatments. Those allocated to the standard cancer treatment (the treatment you would have if you weren’t in the trial) are called the control group. The selection of the group you are in is usually done by a computer and is called randomisation. If you agree to take part in this type of trial neither you nor your doctor will be able to choose which treatment you are given.

Certain details about you (for example your age, gender or the stage of your cancer) are put into the computer first. This is to make sure the different groups in a trial are as similar as possible. There are often more than two groups in the trial.

Each group is followed up at specific times to see how effective the treatments are.

Placebos and double blind trials

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

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 they 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. Sometimes the doctor does not 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 whether or not a patient is getting the new treatment, for example if there are unexpected side effects.

Research on breast 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.

How long does a trial take?

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

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3. Taking part in clinical trials

Every clinical trial has strict guidelines about who can be involved. A trial might be for a certain age group or for a particular type or stage of cancer, which means that not everyone is able to take part. All the information about those who take part 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.

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.

  • 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 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 the trial discuss this with your specialist or research nurse first.

You cannot be entered into a clinical trial without knowing about it and giving your consent.

Once the trial begins

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 (local doctor) 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 or the UK Clinical Trials Gateway

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4. Benefits and drawbacks of taking part in clinical trials

Benefits of taking part in a clinical trial include:

  • You may be one of the first people to benefit from a new treatment.
  • You have the opportunity to help others and improve breast cancer treatment.
  • You will probably be seen more frequently by doctors than people not in the trial as extra information about the effects of the treatment may be needed.
  • You may benefit 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 include:

  • There may be unexpected side effects from the new treatment.
  • The new treatment may not be any more effective than the standard treatment.
  • The new treatment may be effective for some but it may not work for you.
  • There may be extra hospital visits required which may not be convenient or desirable.
  • The extra tests may make you feel more nervous or preoccupied with your breast cancer. These tests may cause additional discomfort and inconvenience. The effects of these additional tests will be explained by the research team.
  • You may not receive the new treatment but be part of the standard treatment (control) group.Back to top

5. Phases of clinical trials 

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 patients 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.

Below, we explain the various phases of clinical trials.

Phase 1 trials

If your breast cancer has not responded to standard treatment, you may be asked to take part in a phase 1 trial. This is the first step in testing a new treatment on people, and the drug is given only to small numbers of patients. People with different types of cancer sometimes take part in the same phase 1 trial.

Phase 1 trials aim to see:

  • whether the treatment has any effect on your cancer
  • how much of a drug can be given safely without causing serious side effects
  • how often it can be given

It will 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 also looked at.

Phase 2 trials

Once the treatment is found to have a benefit and the maximum dose and side effects of the drug have been established, it will be tested in a phase 2 trial. A larger number of patients are needed at this stage.

Phase 2 trials aim to:

  • find out which types of cancer the drug is best suited for
  • find out more about the side effects and how to manage them
  • fine-tune the dose

Not all treatments tested in a phase 1 trial make it to phase 2.

Phase 3 trials

Once the new drug has shown promise as an effective treatment in a phase 2 trial, it’s ready to be tested on much larger numbers of patients in a phase 3 trial.

The aim is to compare the new treatment with the best current or standard treatment to see if the new treatment is better. This could mean the cancer is controlled better or there are fewer side effects of the treatment. In some trials the optimum length of treatment or when best to use the drug in the overall treatment plan are tested.

People who take part in phase 3 trials are put into groups which are usually (but not always) the same size. The groups then have different treatment.

It’s important that the groups of people are as similar as possible. This is because the trial’s organisers 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.

You cannot choose which treatment you will receive. You may not have the new treatment, in which case you will instead 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. This sort of trial is called a randomised controlled trial (RCT).

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 treatment to date.

The size of these trials varies. They can involve up to several thousand patients from many cancer centres in many countries.

Phase 4 trials

These types of trials are sometimes referred to as ‘post-marketing trials’ as they are conducted after a treatment has been shown to work. Phase 4 trials look at treatments that are already available for doctors to prescribe, rather than new ones that are still being developed.

The main reasons for conducting phase 4 trials are to find out more about the side effects and safety of a treatment and what the long-term risks and benefits are.

Find out more about the availability of new cancer drugs.

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Last reviewed: June 2016
Next planned review begins June 2018

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