When trial participants are given an inactive substance that resembles a trial drug, like a sugar pill. Placebos are sometimes tested against real drugs to make sure that the real drug is effective. However, placebos are not commonly used in cancer clinical trials, because intentionally giving patients an ineffective treatment would put them at risk. Instead, experimental treatments are compared with standard-of-care. If there is not a standard-of-care option, trials compare against “best supportive care” which is appropriate palliative care without any other anticancer therapies. You will be told if there is a placebo, standard-of-care or best supportive care involved in a trial you are looking into.