Clinical trials are the vital research link between scientific laboratory discoveries and the availability of new treatments for cancer patients.
For information regarding specific cancer clinical trials open at Western Australian hospitals, please see the WA Cancer Clinical Trials Registry (WACCTR).
- What is a cancer clinical trial?
- Why are clinical trials important?
- Why do people enter clinical trials?
- How do clinical trials help people with cancer?
- How do clinical trials become standard treatment?
- What are some examples of clinical trials that have changed cancer treatment?
- How does a clinical trial work?
- How are clinical trials done?
- What are the risks and side effects?
- How is safety ensured in clinical trials?
- How much does it cost and who pays?
- Is a trial suitable for me?
- What information will I get about the trial?
- Who is eligible for a clinical trial?
- Where are clinical trials run?
- Is there a checklist of information I should have about a trial?
- What is my role in a clinicial trial?
- How can I find a clinical trial?
- What trials are available in Western Australia?
- How can I make an informed decision?
- Where can I get further information?
A clinical trial is a research study that tests new and better ways of improving health in people. It is the final stage of a long and careful process that often starts many years earlier in the laboratory.
Clinical trials are the link between scientific discoveries made in the laboratory and making new treatments available for people with cancer.
Clinical trials may be carried out to:
- find out whether new and promising approaches to prevention, diagnosis and treatment are possible, safe and effective
- look at ways of improving a person's quality of life.
What is a treatment trial?
Treatment trials test new treatments. They are the most common kind of trial.
New treatments can include:
- drugs, such as chemotherapy, hormones and new drugs
- radiation therapy
- surgical methods
- supportive treatments (treatment against the effects of the cancer, not against the cancer itself)
- palliative care
- ways to combine treatments
- new treatments like gene therapy, vaccines and antibodies
- counselling and psychological support
- alternative therapies.
What is a prevention trial?
Prevention trials test new approaches - such as medicines, vitamins, minerals or other supplements - that may lower the risk of getting cancer.
These trials look for the best way to prevent cancer in people who have never had it, or to prevent second new cancers in people cured of their first cancer.
What is a screening trial?
A screening trial test the best way to find cancer, especially in its earliest stages. Examples include Pap smears, mammograms, x-rays and blood tests.
Clinical trials are the best way to improve the treatment and care of people who have cancer. They give us essential information about the effects of different treatments - information that doctors and patients cannot find in any other way. They are how we discover if new treatments are more effective or have fewer side effects.
The results of clinical trials today will improve treatment for people who develop cancer in the future. A new treatment can only become standard treatment if it is proven to be safe and effective in a clinical trial.
Many of the most effective treatments used today are the result of clinical trials done in the past 30 years. Clinical trials also identify risks and side effects, which must be weighed up against the possible benefits of the new treatment.
- In the hope that new treatments will be found that benefit people affected by cancer.
- To possibly get a new treatment that is not available outside the trial.
People being treated as part of a clinical trial do better than people treated outside of a clinical trial. This is probably because people who take part in trials:
- are fitter and better able to comply with treatment than people who aren't in trials
- get the best available treatment or treatment that may be better
- receive extra personalised care and attention from their research nurses and treating doctors as their treatments, tests and follow-up abide by strict plans and guidelines
- get extra information about their disease and treatment.
The benefits of being in a clinical trial are the same for people whether they are in a control group, which receives the best standard treatment, or in the experimental group, which receives the new treatment being tested.
Less than 3% of adults diagnosed with cancer in NSW are enrolled in cancer clinical trials.
Clinical trials have been enormously successful for children. Over 80% of children with cancer are enrolled in clinical trials, compared with less than 15% 20 years ago. As enrolment in clinical trials has improved, the overall survival rate for children with cancer has increased from less than 15% to over 80% and is still climbing.
It normally takes several years before the results of a trial are known.
Researchers follow up what happens to people in the trial, calculate and interpret results, and prepare reports.
To work out whether accepted cancer treatment should change, all trials looking at the same question have to be compared to reach an overall conclusion. For example, a 1998 review of chemotherapy for early breast cancer included 18,000 women in 47 randomised trials who were followed for more than 10 years. All the information from these trials proved beyond doubt that chemotherapy reduced recurrence and improved survival rates in women with early breast cancer.
The results are usually first presented at a meeting of the researchers involved in the trial.
The results are then presented to a meeting of cancer researchers not involved in the trial where there is more scrutiny and debate.
A report is prepared and submitted to a medical journal. The report is peer-reviewed. This means that independent experts in the field provide criticisms, questions and suggestions. If the researchers are able to answer these satisfactorily, the medical journal publishes the report.
When a study is published in a medical journal, it allows many doctors to consider the study, to debate the issues and consider whether they should change the way they treat cancer.
When the treatment is proven to be better, based on the available medical evidence, clear recommendations can be made about the treatment, such as who should have it, in what dose and for how long.
Chemotherapy for cancer of the testis
A recent Australian trial of chemotherapy aimed at curing men with cancer of the testis compared different ways to give three drugs.
One arm of the trial used four treatment cycles of chemotherapy and took 12 weeks to complete. The other arm used three cycles of chemotherapy given in higher doses and took nine weeks.
When the trial began, both combinations were being used in Australia.
The trial was stopped in April 2001 when it became clear that the nine-week treatment using higher doses was more effective than the 12-week treatment, and that it caused fewer side effects. It is now the standard treatment.
Improved outcomes from breast cancer
Death rates from breast cancer have dropped by 30% over the past 20 years. This is probably due to a combination of better treatment - with tamoxifen and chemotherapy - and screening with mammography, which has picked up many cancers early.
Each of these advances occurred because of clinical trials.
The benefits of using tamoxifen in early breast cancer have been established by 55 randomised trials involving 37,000 women, and the benefits of chemotherapy have been established by 47 trials involving 18,000 women.
Quality of Life
Trials not only measure the effect of a new treatment on cancer, but also its wider impact on a person's life.
In phase 3 trials, researchers often ask participants to fill out questionnaires to measure the impact of a treatment on their quality of life.
The questionnaires ask people how they feel and how they are able to carry out everyday tasks. The effects are compared with those of other treatments.
For some types of cancer, there is no proven effective anti-cancer treatment.
In this situation, the standard approach is supportive care. This means treatment against the effects of the cancer, not against the cancer itself.
Studies of new treatments in this situation are often done by giving everyone the best supportive care and assigning half the people to get the new treatment as well. People in trials are never denied treatment that is known to be beneficial.
Each clinical trial aims to answer specific questions that will help find new and better ways of helping people affected by cancer.
Three questions must be answered before a new treatment can be used widely:
1. How should the new treatment be given or done?
2. Does the new treatment seem to work?
3. Is the new treatment better than the best current treatment?
A separate and different clinical trial is needed to answer each of these questions - known as a phase I, II or III clinical trial - because they need to be done in this order.
Phase 1 clinical trials
Phase 1 trials are the first clinical studies that involve people. They are conducted after the treatment has been tested for safety in laboratory tests and in animals.
These trials test:
- how a new treatment should be given (for example, by mouth, injected into the blood or a muscle, or some other way)
- how often it should be given
- if it involves medication, what dose is safe.
Usually a Phase 1 trial involves up to about 20 people, because only a small number of people are needed to find a safe dose.
At first, a few people are given a certain dose and watched carefully for side effects.
If side effects are not a major problem, a few more people are treated at a higher dose. The dose is gradually increased to find the best dose that can be given safely.
These trials carry the greatest uncertainty because there is little experience with the treatment. Generally thy are only suitable for people who have already had all the known effective treatments for their cancer.
Most people in phase 1 trials have incurable cancer. Some people take part in the hope that the treatment may extend their life or improve their quality of life. But often people go on a phase 1 trial because they want to fight their cancer and to help others.
Some people who participate in phase 1 trials sometimes benefit from having the new treatment, but major improvements in their condition are uncommon.
If a phase 1 trial shows the new treatment is safe, the treatment will go on to phase 2 testing.
Phase 2 clinical trials
A Phase 2 clinical trial continues to test the safety of the treatment.
Usually it will involve between 20 and 50 people who have the same kind of cancer and are given the same treatment.
Throughout the study, researchers monitor the people taking part (participants). They watch for side effects and measure the effects of the treatment on their cancer, often using scans and blood tests.
Generally Phase 2 trials are suitable for people who have already had treatments known to be effective for their kind of cancer. The chance of benefiting from treatment in a phase 2 trial depends on the type and stage of the cancer, and on the person's response to previous treatment.
If the treatment continues to be safe and seems effective in a significant number of people, it goes on to phase 3 testing.
Phase 3 clinical trials
Phase 3 clinical trials compare the new treatment with the current standard treatment, to work out which is best.
Phase 3 trials test new drugs, combinations of drugs, types of surgery, ways of giving radiation therapy and other new approaches.
People are assigned at random to receive the best standard treatment or to have the new treatment.
A Phase 3 trial usually involves between hundreds and thousands of people with the same kind of problem. They are usually done at many doctors' offices, clinics and cancer centres around the country or even around the world.
Participants are given the treatment and are watched carefully for side effects, and for effects on their disease, length of life and quality of life. At the end of the study, these effects are compared - to work out which treatment is best and by how much.
Researchers studying cancer treatments follow strict guidelines.
First they must write a plan of the clinical trial. This is called a protocol. Before the trial can begin, the protocol must be reviewed and approved by the ethics committee at each place the trial will be done.
Everyone doing the trial must follow the protocol, which describes:
- reasons behind the trial
- how participants will be selected
- how the treatments will be given
- what tests will be done
- how participants will be monitored
- how the trial will be analysed and reported.
The protocol also describes how the trial may need to be modified if new information becomes available.
Randomised controlled trial
In a randomised controlled trial, some people receive the new treatment while others receive the standard treatment.
The people having the new treatment are known as the trial group and the people having the standard treatment are known as the control group.
A computer randomly assigns people to each group. All treatments tested in a randomised trial are considered likely to be at least as good as the best standard treatment, and possibly better.
Randomisation means your treatment will be selected at random (like drawing a card from a pack), which is usually done by a computer. This is done so each group has a similar mix of people - to ensure the people getting each treatment can be compared without bias.
Neither you nor your doctor can choose which treatment you will receive.
What is blinding?
If you are involved in a trial of a new drug, you and your doctor might not be told which treatment group you are in. This is known as blinding. It is used to eliminate bias from a trial.
If people know they are taking the new treatment, they might expect it to work and report positive reactions because they want to believe they are getting better. This can make the trial results look better than they really are.
Blinding is done by making the medicines look the same so that they cannot be told apart.
What is a placebo?
Sometimes blinding involves placebo (dummy) tablets or injections that look the same as the experimental treatment but don't contain the active ingredient.
In double blind trials, neither you nor your doctor knows which treatment you are getting. You must be told if the trial you are considering is blinded or if some people will receive a placebo.
Many medical treatments have side effects.
The risks of side effects in clinical trials are more uncertain because less is known about the new treatments being tested. This is one of the important reasons for clinical trials - to identify risks and side effects, which must be weighed up against the possible benefits of the new treatment.
In a trial, a person may experience none, some or all of the side effects, which may be mild, moderate or severe. There is also the risk of a previously unknown side effect occurring.
Some clinical trials try to find treatments that are as effective as existing treatments but have fewer side effects. Other trials test treatments for reducing side effects, for example, drugs to reduce nausea caused by chemotherapy.
Cancer is a life-threatening illness that causes its own symptoms. The unavoidable risks of the cancer need to be weighed against the risks and benefits of any treatments.
Talk to your doctor about the risks and side effects of being in a clinical trial.
You should be given comprehensive information to read and discuss before deciding whether to take part in a clinical trial.
The medical profession formally reviews clinical trials. This is called peer review. It is carried out by an ethics committee and other bodies.
Before a trial can begin in a hospital, the ethics committee must judge it to be safe and ethical before approving it.
The ethics committee makes sure people participating in the trial have their rights and interests protected. They ensure people in the trial are offered the best available treatment, and that no beneficial treatments are denied.
Funding is usually covered by organisations such as the Cancer Council and the National Health and Medical Research Council or companies that produce the treatments being tested, like drug companies and device manufacturers.
Taking part in a trial will not cost you more money than not taking part. Some of the tests and treatments involved in a trial are part of standard care. The cost of any extra tests or treatments that are not part of standard care are covered by the trial organisers.
Participation in trials generally means extra work for doctors, nurses and other medical staff. In many cases, the research group or company running the trial provides funds to help pay for some or all of these extra costs.
Cancer trials take time and money. Research funding is limited and competition for funds is fierce! Fewer than one in four research proposals get funding and many trials are inadequately funded.
Your doctor may suggest that you enter a clinical trial.
To carefully assess if a trial is suitable for you should:
- ask your doctor to explain the trial to you
- make sure you understand it completely
- ensure your treating doctor answers any questions you have about the trial
- if you are unsure, ask your doctor if there is someone else you can talk to about the trial. You can also seek a second opinion about the trial and other options.
If the trial is not suitable, the best treatment currently available will be offered.
If you are considering a trial, you should be given a participant information sheet - or fact sheet - about the trial. This should explain everything you need to know about the trial and treatment.
Your doctor should help you understand the trial, without trying to persuade you either way. In turn, you should be open and honest in telling your doctor about your health and information needs.
You should only agree to participate in a trial when you are satisfied and understand all you need to know about it and have considered how it will impact on your life.
Before entering a trial, you must be informed of exactly what is involved in the study, including effects you might expect. This is all part of informed decision making.
Always remember that the choice to join a trial is yours and you can withdraw at any time. Withdrawal will not affect your future care, and you will be returned to receiving the standard treatment for your type of cancer.
Each study has its own guidelines for who can participate. Generally participants are alike in key ways such as the type and stage of cancer, age, gender and other factors. Eligibility criteria are outlined in a trial protocol. Your doctor can tell you if you might be eligible for a trial.
It's important to keep in mind that not all trials are run in every centre or hospital. You may have to travel to a different location to participate.
Check that your doctor has given you the following information:
- your diagnosis - details of the type of cancer you have
- options for investigating, diagnosing and treating your illness
- recommendations for investigating, diagnosing and treating your illness
- uncertainties about your illness and its outcome with or without treatment
- possible benefits with the available and proposed treatments
- any risks that are likely to influence your decisions
- where and how the treatment will be done
- where and how follow-up will be done
- time and costs involved.
Download a printable version of this checklist (pdf, 41kb) with space to write down your answers.
If you participate in a clinical trial, you will be watched closely and detailed records will be kept. You may receive more examinations and tests than are usually given.
Although these tests can be inconvenient, they provide extra information about your progress and the effects of treatment.
You may also be asked to answer questions about how you are feeling - the quality-of-life questionnaires. These additional tests and observations can have their own risks, benefits and inconveniences.
You can withdraw at any time.
During the trial, if it is clear that a treatment is not in your best interest - for example, if it is not working or if you have severe side effects - you or your doctor can stop the treatment at any time.
Withdrawal will not affect your future care, and you will return to receiving the standard treatment for your type of cancer.
The Cancer Council WA provides a number of cancer support services. The Cancer Council WA Helpline 13 11 20 is a one-stop-shop for anyone with questions about cancer, including prevention, diagnosis, treatment and support. Please also visit the patients, families and friends section to learn more about these services.
If you would like to take part in a clinical trial but have not been asked, you can talk to your doctor, who may be involved in a suitable trial or know of one being done elsewhere. If not, they may be able to help you find one.
Trials aren't run in every treatment centre, so you might have to travel to a different location.
If you hear or read in the media about a clinical trial for your type of cancer, you should ask your doctor for more information. Keep in mind that the trial may be for people with other kinds of cancer, and may not be running in your State or country.
A WA Cancer Clinical Trials Registry (WACCTR) has been established by the Cancer Council WA and the Western Australian Clinical Oncology Group. It is an online register listing cancer clinical trials open in Western Australian hospitals. It's purpose is to provide an opportunity for Western Australians to find out about what cancer clinical trials are being undertaken and at which Western Australian hospitals.
The WACCTR includes trials from a wide range of cancer treatment areas of chemotherapy, radiation methods, surgical procedures, preventive measures and lifestyle.
The internet can be a useful source of information for people with cancer. Always check information you find on the Internet with your doctor.
If you decide to take part in a clinical trial, you will be asked to sign an informed consent form. The informed consent form will outline:
- the aim of your treatment
- what the treatments are, and how they are given
- possible alternative treatments
- risks and benefits of each treatment
- any information you need to decide whether or not to take part
- your rights as a participant in the trial
- contact people.
It is required by law.
It is an essential and standard part of every clinical trial.
A copy of this form will be given to you for your records.
Youtube video clips on clinical trials from the National Cancer Institute:
- Guide to understanding clinical trials
- Cancer Clinical Trials: What is a Clinical Trial
- Cancer Clinical Trials: Making Your Decision
- Patient Education Institute - Clinical Trials
Frequently Asked Questions on other websites:
- US National Institute of Health - FAQs about clinical studies
- US National Cancer Institute - Clinical Trials Questions and Answers