A guide to prostate cancer clinical trials
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This page is for men affected by prostate cancer who would like to know more about clinical trials. It describes the different types of trial and what taking part in one means. It also gives details of other sources of support and databases that list current trials taking place.
- What is a clinical trial?
- What are the main aims of a clinical trial?
- What are the different types of trial?
- What do the different phases of trial mean?
- What does randomisation mean?
- What is a placebo?
- Should I take part in a clinical trial?
- What does taking part in a trial involve?
- What are my rights when taking part in a clinical trial?
- Who pays for clinical trials?
- Why does it take so long to get the results from trials?
- How do I find out about trials going on for prostate cancer?
- Questions to ask your doctor
What is a clinical trial?
A clinical trial is a medical research study involving people. People taking part in trials are always volunteers. Trials are done in all areas of medicine, not just cancer. They can involve testing new drugs and combinations of drugs, as well as new technology and procedures.
Clinical trials play a very important role in helping search for new and more effective treatments as well as better ways of diagnosing, screening or preventing a disease. Clinical trials are the best way to find out whether or not a new treatment is better than the current standard treatment.
What are the main aims of a clinical trial?
Clinical trials aim to answer specific questions about a new treatment or procedure. Researchers want to find out if the treatment they are testing:
- Is safe
- Has side effects
- Works better than the existing standard treatment
Doctors all over the world hope that by carrying out clinical trials they will be able to find better treatments. Their aim is to improve the standard of care for people with cancer.
What are the different types of trial?
There are many different types of trial, some of which are more commonly carried out than others. These following paragraphs give you a brief description of the main types of trial used in cancer care.
Prevention trials
These use drugs, diet, vitamins or other supplements that doctors believe may help to lower your risk of developing a certain type of cancer.
Screening trials
Screening trials look at ways of finding a cancer early before symptoms start. Detecting a cancer early means successful treatment is more likely. Before you can effectively screen for a cancer you must have an accurate test to use.
Treatment trials
These are the most common types of clinical trials. They look at the best way of treating a specific health problem such as prostate cancer. These trials test many different types of treatment such as new drugs, new ways of giving treatment or new combinations of treatments. For example, a trial may test whether or not combining hormone therapy with chemotherapy is the best way to treat prostate cancer that has spread to other parts of the body.
Pilot studies
These are small studies designed to test an idea or treatment before doing a larger study. They are also sometimes called ‘feasibility studies’.
Quality of life studies
These studies look at how an illness or its treatment affects you and your daily life. Many of the large scale treatment trials include a quality of life study as part of the trial. Their aim is to improve the comfort and quality of life for people with cancer. For example, with prostate cancer, these studies often look at ways to help control the side effects of cancer and its treatment such as incontinence and erectile problems.
What do the different phases of trial mean?
There are four different phases of clinical trial. Doctors call these phase 1, 2, 3 and 4. You may also see this written with Roman numerals - phase I, II, III and IV.
Phase 1 trials
This is the earliest stage of testing a new drug or treatment that may be effective against cancer. The main aim of this phase is to find a safe dose and monitor side effects. Phase 1 trials involve a small number of people (20 to 30 people) with different types of cancer. The participants are usually in the advanced stages of cancer and have tried all other treatment available to them. They may benefit from being on the trial, but many will not. Phase 1 trials are important though to find possible future treatments for other people with cancer.
Doctors begin by giving the first patient a very small dose of the drug. If this does not cause too many side effects, they will then slowly increase the dose with each patient that goes on the trial. They will closely monitor the side effects on each person. They do this by taking regular blood tests and looking at how your body is coping with and getting rid of the drug. They will also monitor whether or not the drug is helping to shrink your cancer or slow its growth.
Phase 2 trials
This next phase of trial can involve around 50 people but usually no more than 100. Not all drugs tested in phase 1 trials make it to this next phase.
During phase 2 trials, researchers are still looking at dose and side effects. They are also looking to find out if the treatment is working well enough to take it to a phase 3 trial. They can decide whether a treatment is as good as, or better than, the current standard treatment and which types of cancer it is most effective at treating.
Phase 3 trials
Phase 3 trials compare the best existing (standard) treatment with the treatment being tested. Researchers are now trying to find out if the new treatment is better than what we already use. For example, they may test a new type of surgery with a standard one or a completely new drug with the known standard one. The trial may also find out what dose of a drug is most effective. Participants are randomly assigned, usually by a computer, to either the standard treatment or the new one. There is more information further on in this fact sheet about what randomisation means.
This phase of trial usually involves many more people than phase 1 and 2 trials. There can be thousands of people involved from different hospitals in one country or many different countries. This is necessary to make sure that the results can be clearly seen because success rates may only be small.
Phase 4 trials
This phase of trial is done after the new drug has been given a license and has been introduced into everyday medical practice1. The researchers know the new treatment is safe to use and works but other questions may still need to be answered such as:
- Does the drug have any long-term side effects?
- Does the drug have any rare side effects that did not show up in the earlier phase trials?
- Will those people who took the drug live longer than those who did not?
It can take many more years to find answers to these questions.
What does randomisation mean?
Most phase 3 trials are ‘randomised’. This means that the researchers randomly place the people taking part in the trial into two or more groups to avoid bias. The researchers do not have any say in who goes in which group. It is usually decided by a computer.
With two groups, one group is randomly selected to take the new treatment. The current standard treatment, that you would have if you were not in a trial, is given to the other group. This group is known as the ‘control group’.
What is a placebo?
If there is no known standard treatment then a phase 3 trial may compare a new treatment with no treatment at all. This is known as a ‘dummy treatment’ or ‘placebo’. The group assigned to having no treatment would take the ‘placebo’.
This may be a pill, injection or topical ointment made to appear the same as the real medication. But it contains none of the active ingredients so it will not be of any medical value to the person taking it. Using a placebo is quite rare in cancer clinical trials because most people with cancer do need treatment. So if there is a known effective treatment you would not be given a ‘dummy pill’2. Your medical team would tell you on advance if a trial involved a placebo.
Should I take part in a clinical trial?
This can be a very difficult question to answer and only you can decide. Not everyone will be able to go on a trial. Each trial will be looking for men who fit a very specific set of criteria. For example, your PSA level may need to be within a certain range or your cancer may need to be at a particular stage. Other factors will also be taken into account such as how fit you are and if the trial is going on in a centre you can easily get to. The databases listed at the end of this fact sheet will show you the criteria for current trials. Your doctor can also give you more information about your suitability for any trial.
Before making any decisions, it is important to find out as much as you can about a trial including its potential risks and benefits. Each trial will have its differences but generally going on a trial means that you may:
- Be helping to improve the future of cancer treatments for others
- Access newer and perhaps more effective treatments otherwise unavailable outside the trial
- Have more regular check-ups and tests than usual – some people find this very reassuring.
People who take part in clinical trials also have a better health outcome than people with a similar stage and type of cancer who do not participate1. This is because those taking part in the trial:
- Are very closely monitored
- Receive care provided by some of the best health care professionals in the field of cancer research
- Receive on-going care once the trial is over – which means a recurrence may be picked up sooner
- Feel as if they are taking a more active role in their treatment and recovery. This often helps people feel more in control and able to cope with their situation.
Like all treatment, there are also risks involved with taking part in a trial. They include:
- Possible inconvenience of more frequent testing – some people find this makes them more anxious about their cancer
- You may have unexpected side effects from the treatment especially if it is an early phase trial (phase 1 or 2)
- If the trial is randomised you will not get a choice about which treatment you have. You may not even know which treatment you are getting. This is called a ‘blinded’ trial
- As with most treatments, there is the risk that the experimental one may not help you, even if it helps others.
You have to decide whether the risks outweigh the benefits. It is important to have a realistic view of what going on a specific trial means for you. Some suggested questions to ask your doctor are further down this page. The answers may help you make an informed decision about whether or not going on a particular clinical trial is right for you.
What does taking part in a trial involve?
If you decide to take part in a trial, your research team will give you the full details of what this means and what it will involve. All trials have guidelines as to who can and cannot take part. Doctors call these ‘eligibility criteria’. This is to make sure that trials compare similar groups of people and that they are safe. There will be differences between trials with some trials involving a lot more paperwork, tests and trips to the hospital than others.
All trials will involve signing a consent form to say that you understand what taking part means and that you agree to go on the trial. No one can enter a trial without signing this form3. Your medical team will give you information about the trial to read and have time to answer questions before you agree to sign a consent form. The important factors to consider when deciding whether to sign this form include:
- Whether or not you feel comfortable with the frequency and types of tests (blood tests, scans etc) that need to be done during the course of the trial
- The distance to the hospital for the tests and treatment – many people having cancer treatment find travelling long distances very tiring
- Being sure that you understand the possible side effects and risks of having the treatment.
What are my rights when taking part in a clinical trial?
You can leave a trial at any stage you want without giving a reason. Leaving a trial does not mean that you cannot have treatment. Nor does it mean that your medical team will treat you differently. You will still be given the current standard treatment for your stage of cancer.
Like all other medical treatment, the information about you and the clinical trial you are on is confidential. Only your medical team and the staff involved in running the trial will have access to this information. Without your permission this information has to remain private. Your paperwork will be identified using a code number, not your name.
Your doctor will tell you if the trialled treatment is not working so that you can decide whether to continue with the trial.
Who pays for clinical trials?
In the UK, cancer charities, the government or drug companies fund cancer clinical trials. The government provides funding to The Medical Research Council (MRC) and the National Health Service (NHS) to run trials. If you are on a trial and want to know who is funding it ask your doctor. Organisations outside of the UK, such as the ‘European Organisation for Research and Treatment for Cancer’ (EORTC) or the National Cancer Institute (NCI) in the USA, may fund international trials that are taking place in the UK.
Why does it take so long to get the results from trials?
Many people do not realise the cost and long process involved in developing a new treatment. For example, developing a new drug can take between ten and 12 years and it usually costs millions of pounds, often as much as £500 million. The actual clinical trials process usually uses up around 60% of the total cost1.
For example, a new drug must go through various stages of testing. Researchers must first test it in the laboratory. If the drug shows hope they then carry out trials with people. Depending on the type of trial, it may go on for anywhere between one and ten years – on average they tend to last about three to five years. Phase 1 trials are usually much shorter than this.
Once a trial is over it then takes time to collect and analyse the results. It can take years before the researchers know how well treatments work in the long term. It may take another couple of years or more before the results are published.
Before a trial can go ahead, there is a long process of planning, writing a set of rules (a ‘protocol’) and getting approval from various local and independent scientific committees. This process is taken very seriously. A trial should not get approval without this rigorous assessment of looking at:
- Whether the trial is necessary
- How well planned and safe the trial is – is the protocol clear and does it contain all the necessary information (treatment doses, insurance issues etc)?
- Whether or not the researchers are qualified to carry out the trial.
How do I find out about trials going on for prostate cancer?
If you would like to find out about clinical trials going on for men with prostate cancer you can:
- Ask your cancer specialist if there are any local or national trials that may be suitable for you
- Call our confidential Helpline on 0800 074 8383
- Look up one of the clinical trial databases listed below.
Trial databases
You can find details of prostate cancer trials on our research pages.
For a fuller list of trials, you can search for prostate cancer trials going on in the UK and Europe on the following databases:
CancerHelp UK clinical trials database
National Cancer Research Network Trials Portfolio
If you find a trial that you think might be suitable for you print it off and take it along to show your doctor. They can help you decide whether it is likely to be suitable.
Questions to ask your doctor
Do you know of any trials that I could go on for my type and stage of cancer?
Can you tell me the possible advantages and risks from taking part in the trial?
Will I definitely receive the experimental drug or treatment?
How long does the trial go on for?
When will the results of the trial be available?
Will I need to travel to another hospital?
What extra tests will I have to have if I go on the trial?
What happens if something goes wrong when I am on the trial – am I covered by insurance?
Sources used in the compilation of this page
1 The Association of the British Pharmaceutical Industry. Clinical trials: developing new medicines. Oct 2003 [cited February 2007]. Available from: www.abpi.org.uk//publications/briefings/clinical_brief.pdf
2 Medical Research Council. Your health: clinical trials [cited February 2007]. Available from: http://www.mrc.ac.uk/YourHealth/ClinicalTrials/index.htm
3 Souhami R, Tobias J. Cancer and its management. 5th ed. Oxford: Blackwell; 2005.
Reviewed by:
- Richard Gledhill, Prostate Cancer Charity Specialist Nurse, Queen Elizabeth Hospital, Birmingham
- Dr Rhoda Molife, Clinical Research Fellow, Royal Marsden Hospital, Surrey
- Liz Woolf, Head of CancerHelp UK
- The Prostate Cancer Charity Information Volunteers
- The Prostate Cancer Charity Support & Information Specialist Nurses
Written by:
Annie Angle, Specialist Oncology Nurse Writer
Edited by:
Debbie Clayton, Information Manager, The Prostate Cancer Charity
The Prostate Cancer Charity makes every effort to make sure that its services provide up-to-date, unbiased and accurate facts about prostate cancer. We hope that these will add to the medical advice you have had and will help you to make any decisions you may face. Please do continue to talk to your doctor if you are worried about any medical issues.
© The Prostate Cancer Charity August 2007. To be reviewed April 2009