The Genetics Behind Heriditary Cancer


About 1 in 3 Americans will develop some type of cancer during their lifetime. A woman's lifetime risk of breast cancer is about 1 in 8 (11%) and ovarian cancer is about 1 in 70 (1.4%). The risk of developing colon cancer before age 70 for men and women is about 1 in 20 (4-5%). When a family has an inherited risk for cancer, these risks may be much higher.

Most cancer cases are not hereditary and happen by chance or are related to environmental influences. Only 5-10% of cancer is associated with an inherited risk that is passed on by genes from parents to their children.

Some of the features seen in families who have inherited cancers include:

  • Early onset cancer (age<50)
  • Cancer present in multiple generations
  • Rare cancers (ex: male breast cancer, medullary thyroid cancer, adrenal cortical tumors)
  • Bilateral or multiple primary cancers in one person
  • Constellation of tumors consistent with specific cancer syndrome (e.g., breast and ovary)
  • Certain ethnicities (such as the Ashkenazi Jewish population)

The Cancer Genetics and Prevention Program provides genetic counseling and testing for many different hereditary cancer syndromes including: Hereditary Breast and Ovarian Cancer Syndrome (HBOC), Lynch Syndrome (HNPCC), Familial Adenomatous Polyposis (FAP), MYH-associated Polyposis Syndrome, Li Fraumeni Syndrome, Cowden Syndrome, Hereditary Diffuse Gastric Cancer Syndrome and other rare hereditary cancer syndromes.