What are clinical trials?

Clinical trials are medical research studies involving people. They help us to understand more about cancer, how we treat it and improve how people live with it.

All new treatments have to be thoroughly tested. Researchers test possible new drugs in a laboratory to begin with. If they look promising, they are carefully tested in people.

Clinical trials look at different areas.

Risks and causes – how genetics, lifestyle and other factors can increase people's risk of cancer.
Preventing cancer – using treatment or lifestyle changes to reduce risk.
Screening – tests for the general population or people with higher than average risk of cancer before they have symptoms.
Diagnosing cancer – new tests, scans or procedures to improve diagnosis and pick up cancer earlier.
Treatments – new treatments such as cancer drugs, radiotherapy or surgery. Trials also look at different doses or combinations of treatment.
Controlling symptoms or side effects – new drugs or complementary therapies might help with this.
Support and information - for people with cancer and their carers, families or friends

The 5 minute video below tells you more about clinical trials:

Cancer Research Trials | Cancer Research UK

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Read the full video transcript.

Taking part in a trial can involve different things. For example:

trying a new medicine or treatment
giving samples, such as blood or tissue
filling in a questionnaire
having a scan

You might have just one appointment, or you could be part of a trial for a few years.

The aim of clinical trials

Trials aim to find out if a new treatment or procedure:

is safe
has side effects
works better than the current used treatment
affects quality of life

What trials tell us

Some trials will show that a new treatment works better than an existing treatment. Others will tell us more about the side effects, or what happens to a drug in the body.

Not all clinical trials will result in new and better treatment. Results sometimes show that:

the treatment being tested does not work or
that it has side effects that are worse than with existing treatments.

It all adds to our knowledge of cancer and how best to treat it.

Researchers also want to look at the impact a treatment has on you and your life. For example, how often you have to travel to the hospital. Studies that look at the effect a treatment or procedure has on your day to day life are sometimes called quality of life studies. Many trials include a quality of life study.