Standard treatment – This is the current most effective treatment or care given to people for their disease or condition. For example, standard treatment for newly diagnosed early breast cancer is surgery to remove the breast tumour, often followed by radiotherapy, hormone therapy and/or chemotherapy.
In some cases, there is no known useful medication or treatment, but patients will be monitored regularly. That is then the currently available best standard of care. This would be the case for women who have completed standard surgery, radiotherapy, hormone therapy and/or chemotherapy for early breast cancer.
Placebo – This is an inactive or fake treatment made to look, taste or feel like the treatment being tested, but doesn’t have any active (therapeutic) ingredients (if a medicine) or a remedial effect (if another type of treatment).
A placebo is used to compare treatments to see whether the patients’ outcome is because of the actual treatment or because of other factors associated with being in the study. If the people given the experimental treatment show more improvement than those given the placebo, this provides strong evidence that it’s the experimental treatment that is responsible rather than other factors.
Placebos are not often used in cancer treatment trials. Trials that include a placebo are only approved if the placebo is used together with the best standard therapy for the cancer or condition being studied. Participants will be told if a study uses a placebo.
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A type of clinical trial in which the study participants receive each treatment in a random order. In these studies, the two arms of the trial have their assigned treatment for a period of time before swapping and having the other treatment. This enables all participants to experience all treatments, which helps confirm which is the most effective.
Crossover studies are often used when researchers feel it would be difficult to recruit participants willing to risk not receiving a promising new treatment.
If the participant doesn’t know which arm of a study they’re in, this is called a blind study. Some randomised controlled trials are called double-blind studies as neither the participant nor other members of the trial team know whether the participant is receiving the experimental treatment or the control treatment. In a double-blinded trial, even the lead researchers only discover who is in each arm of the study at the end of the trial when the results are being analysed.
Blinding aims to reduce bias in the reporting of benefits and side effects. For example, if you or your doctor knew you were having standard treatment, you might feel disappointed that you didn’t receive the experimental treatment and this may affect your wellbeing. However, if you or your doctor knew you were having the experimental treatment, then you might report that you’re feeling better than you actually are because you want the treatment to work. If you don’t know which treatment you’re having, the results are less likely to be influenced by you or your doctor’s thoughts.
If necessary for safety reasons, your doctor can find out what treatment you’re having by contacting those running the study.
Blinding is only used when participants can’t tell what treatment they’re having or can’t tell the difference between the two types of treatment. For example, it is hard to disguise surgery and massage, or two noticeably different control and experimental treatments.