Is cancer a genetic disease?

Yes. The National Cancer Institute explains that cancer is a genetic disease—that is, it is caused by changes to genes that control the way our cells function, especially how they grow and divide.

However, "genetic" does not always mean "inherited." Genetic changes that cause cancer can happen because of errors that occur as cells divide, because of damage to DNA from harmful substances in the environment (such as chemicals in tobacco smoke and ultraviolet rays from the sun), or because they were inherited from a parent.

The gene changes that contribute to cancer tend to affect three main types of genes: proto-oncogenes, tumor suppressor genes, and DNA repair genes. These changes are sometimes called "drivers" of cancer.

Each person's cancer has a unique combination of genetic changes, and even within the same tumor, different cells may have different changes. If you are wondering whether an inherited change might affect you or your family, a healthcare team or genetic counselor can offer more guidance.