- controlled trials
- randomised trials
- placebo and blind trials.
If you're struggling to find what you need, call our Support line on 0808 808 0000 (Monday to Friday, 9am-8pm)More ways to contact us
If you take part in a trial you may hear terms such as:
In most controlled trials, one group of patients will have the standard treatment for their cancer type. The other group will have the trial treatment which is being tested. The results are then compared to see which treatment works and if the side effects are worse or better.
Sometimes when there isn’t a standard treatment available, one of the groups is given a placebo treatment instead. This looks the same as the treatment being studied but it contains no medicine. It is also called an inactive treatment.
To decide who goes into each group in a fair way, a computer places patients into treatment groups. This is called randomisation.
You may not be told which treatment group you are in. This is called a blind trial. In some trials called double blind trials, neither the patient nor the doctor will know which treatment they are getting.
In most trials, one group of patients will have the trial treatment and one group will have the standard treatment. Groups are randomly selected (see ‘randomised trials’ below).
Sometimes, the standard treatment is to ‘watch and wait’. This is when you do not need to have any treatment, unless the cancer starts to develop or cause symptoms.
The people with cancer who are having the trial treatment are called the trial group. The people having the standard treatment are called the control group. The researchers will compare the results of the trial group against the control group.
Researchers compare the results of both groups to find out if:
If the trial group shows any improvement, the researchers also measure:
Some phase 2 and phase 3 trials are randomised, controlled trials. This means that a computer programme randomly (by chance) chooses the groups for each treatment.
The computer matches the different groups to make sure they are as similar as possible. For example, this means they will have a mix of people with similar ages, gender or state of health.
Everyone taking part will get a code number and will be put into to the different treatment groups randomly. They may get:
When people are put into treatment groups by a computer, it avoids any bias. If doctors or researchers decide who should get which treatment, they could be influenced by what they already know. Without realising it, they may put people more likely to respond to a new treatment into that particular group. This would affect the results of the trial and make a treatment look better than it is.
A placebo is an inactive treatment that looks the same as the drug or treatment that is being tested. But it does not act on the cancer.
It may be used when a new drug is added to a standard treatment. One group will get the standard treatment plus the new drug. The other group will get the standard treatment plus a placebo. If you are in this group, it does not mean you will not receive any treatment. The placebo is given along with the standard treatment.
You will not know if you are getting the trial treatment or a placebo. This is called a blind trial. Researchers compare the responses to the placebo and the treatment being tested to find out if it has any benefit.
In many trials, doctors do not know whether you are getting the placebo or the treatment being tested. These are called double-blind trials.
In an emergency, your doctor can find out this information from the trial co-ordinators or the pharmacy department at the hospital.
Blind trials or double-blind trials aim to reduce any bias. For example, knowing you are having a new treatment might make you feel more positive or negative. This could influence what you report to the researchers. Also, your doctor may judge your response differently if they know you are having a treatment that they feel positive about.
Clinical trials are medical research trials involving people.
A potentially new cancer treatment or drug will go through different phases of clinical trials before it is approved.
It can take many years before the results of a clinical trial are known.
Our booklet explains how clinical trials are carried out, when you might be invited to take part and what you could expect if you do.
All types of treatment can have different side effects. Know what to expect to help you find the best way for you to handle them.
Our campaigns fight for real change for people affected by cancer. By taking action, you can help transform the lives of people with cancer. Join us in demanding the best in cancer support.
What's happening near you? Find out about support groups, where to get information and how to get involved with Macmillan where you are.
Our Online Community is always open and full of people ready to support you.
Share experiences and get support about any types of cancer treatment, including chemotherapy, radiotherapy, surgery, biological or hormonal therapies, transplants, and clinical trials.
We rely on a number of sources to gather evidence for our information. If you’d like further information on the sources we use, please feel free to contact us on: firstname.lastname@example.org
All our information is reviewed by cancer or other relevant professionals to ensure that it’s accurate and reflects the best evidence available. We thank all those people who have provided expert review for the information on this page.
Our information is also reviewed by people affected by cancer to ensure it is as relevant and accessible as possible. Thank you to all those people who reviewed what you're reading and have helped our information to develop.
You could help us too when you join our Cancer Voices Network – find out more at: http://www.macmillan.org.uk/cancervoices
Need to talk? Call us free* 0808 808 00 00 Monday to Friday, 9am-8pm
© Macmillan Cancer Support, registered charity in England and Wales (261017), Scotland (SC039907) and the Isle of Man (604). Also operating in Northern Ireland. A company limited by guarantee, registered in England and Wales company number 2400969. Isle of Man company number 4694F. Registered office: 89 Albert Embankment, London SE1 7UQ. VAT no: 668265007
We make every effort to ensure that the information we provide is accurate and up-to-date but it should not be relied upon as a substitute for specialist professional advice tailored to your situation. So far as is permitted by law, Macmillan does not accept liability in relation to the use of any information contained in this publication or third party information or websites included or referred to in it.