Cancer Research UK on Google+ Cancer Research UK on Facebook Cancer Research UK on Twitter

What you should be told about a trial

Women discussing trials

This page is about what you must be told before you take part in a clinical trial. It includes information on


What informed consent is

By law, researchers must explain to you what a trial involves before you agree to take part. You must then sign a statement to say you have been told, and understand, what taking part in the trial means. This is called informed consent. To give informed consent, you must have been told

  • What the trial is trying to find out
  • What treatment you will be asked to have
  • What the likely risks and side effects will be
  • What the benefits may be
  • What tests or check-ups you will be expected to have
  • How often you will be seen in follow up appointments and for how long
  • Whether any of your blood or tissue samples will be kept or used for further research

This information should all be included in the patient information sheet (PIS), or patient information leaflet (PIL). The research team will give you a copy of the PIS to take home and read in your own time. You can refer back to this when you are deciding whether to take part in the trial or not. You can also discuss it with your friends, family, GP, specialist or nurse.

If the trial is investigating a very new treatment, the research team may not know much about the side effects yet. But you should be told everything they do know that is relevant.

You cannot enter a trial without signing your agreement. You are entitled to ask any question you like if there is anything you do not understand.

Good researchers accept that informed consent is an ongoing process throughout the trial. So you should always be able to ask questions, and get answers to them, while you are in the trial.

Remember - you can withdraw from a trial at any time, without giving a reason. You will then be entitled to the standard treatment for your type and stage of cancer.


Blood and tissue samples in the trial

In some trials, you will be asked to give blood or samples of your cancer that will be used for further research. Usually, tissue samples will be taken when you are having surgery or a biopsy of your cancer. And the blood is usually taken when you need to give a blood sample anyway. So you shouldn't have to have any extra procedures or tests.

This further research may help to identify which patients would benefit most from a new treatment. Or to find out who is most likely to have side effects. All additional research of this kind must be approved by the Research Ethics Committee. And you have to be told and give your permission before they take any samples. You can say no, of course. You should still be able to enter the main trial.

Rate this page:
Submit rating


Rated 5 out of 5 based on 3 votes
Rate this page
Rate this page for no comments box
Please enter feedback to continue submitting
Send feedback
Question about cancer? Contact our information nurse team

No Error

Updated: 10 October 2013