There are also genetic risk factors for cancer.

Inherited mutations in the BRCA genes are an example. These genes encode a protein which has an important role in repairing DNA damage. The BRCA protein is defective in people with these mutations. Typically a cell acquires up to six non-inherited mutations through DNA damage in which the encoded proteins have different physiological functions before it starts to divide in an uncontrolled way (= cancer).

People with inherited mutations in the BRCA genes are at high risk of breast and/or ovarian cancer. These mutations can be screened for. People with them sometimes choose to have prophylactic mastectomies and/or removal of their ovaries.