A trial is used to test out an idea or a drug, a clinical trial means one that is conducted by doctors and nurses, usually in a hospital. There are lots of different trials and it can be confusing trying to work out what they show and why they are different.
A clinical trial can be used to test an idea e.g. does eating 5 or more portions of fruit and veg a day protect you from cancer? or they can be used to test a specific treatment e.g. does avastin improve survival in people with bowel cancer.
The whole idea of a clinical trial is to make sure it is a fair test, so there are usually lots of rules about who can enter a trial, some trials look at healthy people to measure their risk of developing cancer, some trials take people with one specific type of cancer and compare treatments.
Usually people are “recruited” to clinical trials by their consultant or a research nurse. So you will often be asked if you want to take part in a trial. This is completely up to you and won’t affect the treatment you receive from your GP or consultant. There are over 200 different types of cancer, so not every hospital, in every area will be carrying out research into your specific type of cancer. Research is very expensive, some hospitals have experts that specialise in breast cancer research, some hospitals have experts that specialise in bowel cancer research. However, if a clinical trial shows a positive result, those treatments will be available to everyone, although this can take time.
Trials are usually split up into different “phases”. Phase 1 clinical trials usually recruit a very small number of people (often less than 50) and are used to see the side effects and safe dose of new treatments. Usually people in these trials have advanced cancer and have had all the normal treatments. They may benefit from the trial, but many people won’t.
In phase 2 (phase II) trials the researchers narrow down which specific types of cancer the treatment works for and learn more about the side effects and safe dose of the drug. Phase 2 studies usually involve 100-200 people.
If a treatment passes phase 1 and phase 2 trials it will move on to phase 3 (but many of the treatments tested do NOT make it to phase 3 trials, the treatments might be too toxic or they might not work). Phase 3 (phase III) trials involve thousands of people and often many different hospitals, the new treatment needs to be better than the best treatment currently available.
Even once a drug has been shown to be better in a phase 3 trial, it is still followed up in a phase 4 (IV) trial to learn more about side effects and long term effects.
You can read more about clinical trials on the Cancer Research UK website “Understanding Clinical Trials – Types of Trials” or on the UK Clinical Research Collaboration “Cinical Trials: What they are and What they’re not”
What if you aren’t sick? Can you still take part in trials?
Yes, many trials need a “normal” population, there are lots of different types of observational trials, where you study people and try and work out what is different. The usually have “cohorts”, which means a group of people. e.g. people who eat lots of fruit and veg vs people who don’t. Some trials are short, e.g. run for a few weeks some are very long and run for decades. Often trials are randomized, that means people are divided up into different groups randomly, usually using a computer program (For a list of both online and paid randomistaion services click here).
A cross sectional study looks at the present time only. A study that looks at the present time and things that happened in the past is called a retrospective study. A study that starts now and carries on into the future is called a prospective study.
There are other types of trials and you can find more information on Cancer Research UK ‘s website “Understanding Clinical Trials – Other types of trials”
Where can you find out more information about the trials going on in the UK? If you have cancer the best person to ask is your consultant or your GP. Cancer Research UK have a list of all the clinical trials currently going on in the UK (it includes all cancer trials, not just those ones funded by Cancer Research UK.)
Click on this link to search the database:
You can include place names, so when I searched for “All Cancers” I found 61 trials ongoing in Aberdeen. These covered a wide range of cancer including leukemia, lymphoma, bowel cancer, lung cancer, ovarian cancer, stomach cancer, prostate cancer and breast cancer.
For trials looking at the effect of diet on disease (all sorts of diseases, not just cancer), visit the Human Nutrition Unit at Aberdeen University’s Rowett Research Institute.
Have you taken part in a clinical trial? Would you want to? Please feel free to leave a comment below.