Though we have not identified genetic causes for all types of cancer, we do know several gene changes, or mutations, that can be passed down from parent to child and increase a person's risk of developing the disease. These changes are known as hereditary cancer syndromes.

Hereditary Breast & Ovarian Cancer Syndrome

The most common type of inherited breast cancer is hereditary breast and ovarian cancer syndrome (HBOC). HBOC is caused by mutations in the BRCA1 and BRCA2 genes. A woman with an inherited mutation in the BRCA genes has a higher chance of developing breast and ovarian cancer in her lifetime than a woman who does not carry a mutation. A man with an inherited mutation in the BRCA genes has a higher chance to develop breast and prostate cancer in his lifetime. In addition, some families have higher incidence of pancreatic cancer, melanoma and other cancers.

Cowden Syndrome

Cowden syndrome (CS) is characterized by multiple tumor-like growths and an increased risk of certain cancers. The majority of patients with CS develop small, non-cancerous growths, or hamartomas, of the skin and mucous membranes, but these growths can also occur in the intestinal tract or brain. Individuals with CS also have an increased risk of developing benign and malignant tumors of the breast, uterus and thyroid. CS is associated with mutations in the PTEN gene.

Lynch syndrome (hereditary Non-polyposis Colorectal Cancer Syndrome

Lynch syndrome (HNPCC) is characterized by early age onset colorectal cancer and uterine (endometrial) cancer as well as other extracolonic tumors. Lynch Syndrome is caused by mutations in DNA mismatch repair genes (MLH1, MSH2, MSH6 or PMS2). A variant of Lynch syndrome called Muir Torre Syndrome is associated with increased risk for certain skin tumors.

Hereditary Leukemia and Hematologic Malignancies Syndromes

In recent years, researchers have found about a dozen inherited genetic conditions that can lead to leukemia and related blood diseases such as myelodysplastic syndrome, acute myeloid leukemia and aplastic anemia. While large-scale studies of leukemia patients haven’t been completed, doctors estimate that about 5-10% of all leukemia cases are hereditary. Leukemia patients with a family history of the disease should consider genetic testing to learn if their disease has an inherited component. This information may impact a patient’s treatment plans. MD Anderson patients suspected of having one of these conditions should be seen by our Hereditary Leukemia Clinic.

Familial adenomatous polyposis (FAP)

Familial adenomatous polyposis (FAP) or Gardner's Syndrome is a colon cancer predisposition syndrome in which hundreds to thousands of precancerous colon polyps (called adenomas) develop throughout the gastrointestinal tract (mostly in the colon and rectum but also in the stomach and small intestine).

Attenuated FAP (AFAP) is a milder form of FAP and is associated with increased risk for colon cancer but fewer number of colon polyps. Gardner's syndrome is associated with the typical number of polyps as in FAP, but also osteomas (benign tumors of the bone) and soft tissue tumors (called desmoids). FAP is associated with mutations in the APC gene. There are other more recently described predispositions to polyposis that are associated with different genes.

Li-Fraumeni Syndrome

Li-Fraumeni Syndrome (LFS) is a rare genetic condition characterized by an increased risk of developing multiple types of cancer. The cancers that occur in LFS can be diagnosed during childhood, adolescence or adulthood. Most individuals with LFS are found to have mutations in the TP53 gene. The most common types of cancer associated with LFS include:

Soft tissue sarcomas (tumor in fat, muscle, nerve, joint, blood vessel, bone or deep skin)

Breast cancer

Leukemia

Lung cancer

Brain tumors

Adrenal gland cancer

Von Hippel-Lindau disease

Von Hippel-Lindau disease (VHL) is a multi-system disorder characterized by abnormal growth of blood vessels (called hemangioblastomas or angiomas). Hemangioblastomas may develop in the retina, certain areas of the brain, the spinal cord and other parts of the nervous system. Other types of tumors can develop in the adrenal gland, kidney and pancreas. Individuals with VHL also have a higher risk to develop certain types of cancer, especially kidney cancer. Nearly all individuals with VHL are found to have mutations in the VHL gene.

Multiple endocrine neoplasias

Multiple endocrine neoplasia (MEN) syndromes received their name because they predispose people to develop tumors of the endocrine glands. The endocrine system is comprised of glands that secrete hormones into the bloodstream that control numerous processes within the body. The endocrine system is instrumental in regulating mood, growth and development and metabolism, as well as sexual function and reproductive processes.

Currently, there are two distinct MEN syndromes: MEN1 (typically characterized by growths of the pituitary, parathyroid, and pancreas) and MEN2 (typically characterized by medullary thyroid cancer).