What you should be told about a clinical trial

Giving samples in clinical trials

The trial team may ask your permission to take blood and tissue samples as part of a trial.

Blood and tissue samples in cancer research

You usually have a sample of blood taken from a vein in your arm. Where possible, blood samples for research are taken at the same time as routine blood tests.

A tissue sample is a sample of cells removed from your cancer. You might have this taken as part of a when you are diagnosed. Or when you have an operation to remove your cancer.

Doctors and researchers look at blood and tissue samples in the laboratory. They use these samples to learn more about:

how cancers develop so they can find new ways to prevent them
changes in hormones, chemicals or cells to help find new ways to diagnose cancer
how cancer cells behave so they can find new ways to kill them
changes in the cancer cells and which treatments can target these changes
how new treatments affect cancer cells and the body
which treatments work best for people with particular types of cancer
new ways to monitor cancer
better ways of controlling side effects and symptoms

Collecting samples

The research team need to take blood or tissue samples before you start treatment. This is to make sure the trial is suitable for you. Many clinical trials are designed to test treatments for people with a specific type of cancer. And some are designed to test treatments that only work for people with cancers that produce certain proteins or chemical markers.

Your doctor or nurse will ask your permission before taking samples for research. They will give you some written information about taking the samples and what happens to them. You’ll have the chance to ask the research team any questions you have. They will ask you to sign a form giving your consent. This is called informed consent.

You might be asked to give blood or tissue samples at different times throughout a trial. If you are taking part in a phase 1 or 2 trial, you are often asked to give quite a few samples, usually blood samples. This is because it's helpful for the research team to know as much as possible about the new treatment and how it affects people. You can find out more about the different phases of trials.

Some clinical trials also collect samples of blood or tissue for future research. This is nearly always optional. You can say no to this part of the research if you don’t want to give these samples. It won’t affect you taking part in the main trial.

People who do not have cancer, or any other illness, may also be asked to donate blood or tissue samples. Researchers can use these to find differences between healthy cells and cancer cells.

Other types of samples

Researchers can use different types of samples to help with their research.

These include:

fluids removed using a needle and syringe from joints, or
fluid build up from around the tummy (called ) or around the lungs ()
urine, spit (sputum), saliva and tears
cells from skin, hair, nails, the inside of the mouth, the eye, or the neck of the womb (cervix)
poo samples to look at the

What happens to the samples?

Researchers store samples in laboratories called biobanks. These are like libraries. They keep the samples with some details of your medical history, but no personal details. The samples cannot be traced back to you. A computer stores the medical information about each sample. This is so that researchers can find the samples they need.

The Human Tissue Authority (HTA) produce guidelines for the safe storage of tissue samples. They also give advice about making sure the samples are kept confidentially. You can read about their work and about donating tissue for research on their website.