Retinoids are substances that help regulate the work of genes as cells grow and divide. Chemically related to vitamin A, retinoids are used to treat a wide variety of conditions and diseases, including several cancers.

Retinoids have been shown to be effective in reducing the risk of some cancers or in reducing the risk of a recurrence of cancer. These medications have been approved by the U.S. Food and Drug Administration (FDA) for use in the treatment of certain cancers, particularly skin cancers. They are usually administered in a topical gel or orally, depending on the condition being treated.

The National Cancer Institute is studying retinoids for their potential in preventing or treating other types of cancer, such as breast, bladder and liver cancers. There have been numerous clinical trials examining the effectiveness of retinoids as treatment for these cancers, as well as certain childhood cancers. However, retinoids can be associated with serious side effects, including a high risk of birth defects when used by pregnant women. More research is necessary to determine what role retinoids can play in the prevention and treatment of other types of cancers.