Clinical trials are essential in order to find out whether a new treatment (or a new way of using an existing treatment) can improve the outlook for cancer patients. Only by comparing the new treatment with the best of the treatments already available will doctors know if it offers any benefit.

If earlier studies have suggested that the new treatment is as good as, or might even be better than, the current 'best' treatment then one or more clinical trials will be set up to compare them. If doctors already knew for sure whether the old or the new treatment was better then they would not need to do the trial.

When the choice of treatment is done independently from the patient and their doctor it is known as a 'random' choice. So the treatment is decided by random selection and this type of trial is known as a randomised clinical trial.

There is almost universal agreement among doctors and scientists that randomised clinical trials are the best way of deciding if a new treatment really does have anything to offer. So you can be reassured that although it may seem rather strange, leaving your choice of treatment to a computer is, in this situation, the best way of making that decision.

These days nearly all randomised trials are designed by teams of expert doctors, nurses and scientists. They will have produced a protocol, or plan, for how the trial should be done. This will include precise details of the treatments to be given. The protocols are then reviewed by a Research Ethics Committee before they are approved.

The Research Ethics Committees are completely independent from the team who designed the trial. The Ethics Committee  includes lay members, nurses, GPs, hospital doctors and other health professionals within the NHS. Only when they are completely satisfied and have given their approval can the trial begin. No trial would be approved by an Ethics Committee if there was clear evidence that one of the treatments to be tested was either much better or much worse than the others.

So you have the reassurance that not only will your randomised trial have been planned by experts, in order to compare the best possible treatments, but their plans will, in turn, have been closely examined by an independent panel who have the patients' interest at heart.