Cancer, or a predisposition towards cancer, that runs in families. Familial cancer account for approximately 5-10% of cancers overall. In general this involves several members of a family developing the same type of cancer, typically it develops at an earlier age than sporadic (non-inherited) cancers. The cancer may be due to an inherited gene mutation. For example the BRCA1 gene is mutated in some families with hereditary breast and ovarian cancers. Cancer is common (1 in 3 people develop cancer) so a number of people with cancer in the same family does not necessarily imply the cancer is hereditary. If you are worried you have a familial cancer you should discuss this with your doctor. See also: Hereditary-Mutation See also: Mutation.
Cancer that occurs in families more often than would be expected by chance. These cancers often occur at an early age, and may indicate the presence of a gene mutation that increases the risk of cancer. They may also be a sign of shared environmental or lifestyle factors.