There may be some risks associated with being a participant in a clinical trial too. There may be unpleasant, serious or even life-threatening side effects to experimental treatment that are presently unknown. The treatment may not provoke the response anticipated and be ineffective resulting in dashed hopes of some patients.

The protocol may require more time and involvement than is usual for standard of care treatment. This may include more hospital or clinic visits, stricter adherence to dietary and treatment regimens or complex dosage requirements. Whilst some patients see this as a positive thing some patients do not wish to attend more regular appointments as they see it as a constant reminder they have or had cancer.  Frequent hospital visits may be difficult for patients who need to travel to the appointments or are feeling unwell.

Taking part in a randomised trial, may mean that rather than receive the trial medication(s) you may receive placebo(s). If the trial is a double blind randomised trial, neither you or the medical team involved in your care will know which type of medication you are receiving. The tests and appointment schedules however would be the same for both those receiving the trial medication(s) and the placebo(s).