Giving samples in clinical trials

Blood and body tissue samples are vital for cancer research. This page is about giving samples as part of a trial. There is information about

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 biopsy Open a glossary item 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
how new treatments affect cancer cells
which treatments work best for people with particular types of cancer
new ways to monitor cancer
better ways of controlling side effects and symptoms

Photo of a man having a blood test

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 ask your permission before taking samples for research. They give you some written information about taking the samples. The written information tells what will happen to your sample. The team ask you to sign a form giving consent. You’ll have a chance to ask them any questions you may have.

Some clinical trials also include plans to 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, abscesses or cysts
fluid build up from around the tummy (called ascites ) or around the lungs (pleural effusion )
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 microbiome

What happens to your sample

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) produces 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.