What is a cancer prevention trial?

A cancer prevention trial looks at ways to prevent cancer from developing in the first place, rather than testing a treatment for cancer that's already present. This is different from a treatment trial, which involves people who currently have cancer.

Most participants in prevention trials don't currently have cancer. Instead, they're often people considered at high risk of developing cancer, based on factors like family history or other risk factors. Prevention trials also sometimes include people who've already had cancer once and are at high risk of developing a new cancer.

Prevention trials might test a range of approaches, such as a medication or another intervention aimed at lowering the chance that cancer develops. Like other types of clinical trials, prevention trials go through review and monitoring to protect the safety of everyone taking part.