Information About Hereditary Cancers
Hereditary cancer is cancer risk that is inherited or passed on in a family. Unlike most cancer, hereditary cancer results from an abnormal alteration in a single gene. Approximately 5 percent to 10 percent of all cancers are considered to be hereditary.
Families may have hereditary cancer if there are multiple people in the family with cancer, including more than one generation of family members with the disease. In addition, people diagnosed at a young age are more likely to have hereditary cancer. Some types of hereditary cancer are more common among certain ethnic groups.
There are many different hereditary cancer syndromes, some of which are listed below. The specific syndrome name does not indicate all of the cancer types family members may be at risk to develop. For example, families with a hereditary breast cancer syndrome also have an increased risk of developing ovarian cancer. Knowing the different cancers associated with a cancer syndrome allows family members to undergo earlier and more frequent cancer screening.
- Breast-ovarian cancer syndrome 1 results from an abnormal change in the BRCA1 gene. Female family members have an estimated 80 percent lifetime chance of developing breast cancer and a 40 percent to 60 percent lifetime chance of developing ovarian cancer. Mammography and breast magnetic resonance imaging (MRI) screening as well as ovarian cancer screening are recommended for female family members with a gene alteration.
- Breast-ovarian cancer syndrome 2 results from an abnormal change in the BRCA2 gene. Female family members have an 80 percent lifetime chance of developing breast cancer and a 20 percent lifetime chance for ovarian cancer. Other cancers are associated with this syndrome, including melanoma and pancreatic, prostate, gastric and liver cancers. Mammography and breast magnetic resonance imaging (MRI) screening as well as ovarian cancer screening are recommended for female family members with a gene alteration.
- Familial adenomatous polyposis is a hereditary colon cancer syndrome that results from an abnormal alteration in the APC gene. Individuals develop hundreds to thousands of polyps. Since any of the polyps may develop into cancer, removal of the colon is recommended. Polyps may develop in other areas of the digestive system, requiring lifelong cancer screening.
- Familial melanoma results from an abnormal alteration in at least one of three genes. Families with familial melanoma have an increased chance of developing melanoma and may have an increased chance for pancreatic and brain tumors. Monthly skin self-exams and clinical examinations by a dermatologist every six months are recommended.
- Hereditary nonpolyposis colon cancer (HNPCC) is a hereditary colon cancer syndrome resulting from an abnormal change in one of at least four genes. Family members with HNPCC have an 80 percent lifetime risk of developing colon cancer. Female family members have a 40 percent to 60 percent lifetime risk of developing uterine cancer. Other cancers, such as gastric or kidney tumors, may be associated with this syndrome. Colon cancer screening and uterine cancer screening are recommended, beginning at a young age. Other screening may be recommended based on family history.
- Multiple endocrine neoplasia type 2A (MEN2A) results from an abnormal alteration in the RET gene. Family members have an increased chance of developing medullary thyroid cancer, hyperparathyroidism (overactive parathryoid gland) and tumors of the adrenal gland (known as pheochromocytoma). Removal of the thyroid gland is recommended.
- Von Hippel Lindau(VHL)syndrome results from an abnormal change in the VHL gene. Families with VHL syndrome have an increased risk of developing kidney cancer, tumors of adrenal gland (pheochromocytoma), and brain and spinal tumors. Tumors found on the retina, located in the back of the eye, are characteristic of this syndrome. Evaluations of the eyes, kidneys, brain and spinal cord are recommended on a yearly basis.