About Hereditary Cancer

People at risk for hereditary cancers may benefit from medical genetic testing ordered by healthcare professionals and complemented by genetic counseling.

What causes inherited cancer?

Cancer can be caused by many different factors. Most risk factors are not hereditary, including environmental exposure to cancer-causing substances, physical traits such as obesity, and exposure to alcohol and cigarette smoke.
Hereditary cancer is a term used to describe cancers that may be caused by genetic mutations passed down in families through our DNA. There are thousands of mutations in dozens of genes that have been associated with a medically-manageable increased risk of many different cancers.

Hereditary Breast and Ovarian Cancer (HBOC)

HBOC is caused by mutations in either the BRCA1 or BRCA2 genes. Women who have HBOC typically have an increased risk of developing breast cancer, ovarian cancer, and pancreatic cancer. Men who carry these mutations are also at risk for male breast cancer, pancreatic cancer, and aggressive prostate cancer.

The likelihood of a family passing on HBOC increases in each of the following situations:

  • 1 or more women are diagnosed at age 45 or younger
  • 1 or more women are diagnosed with breast cancer before age 50 and the family has a history of other cancers
  • There are multiple cases of breast or ovarian cancer on the same side of a family going back generations 
  • A woman receives a second breast cancer diagnosis or has both breast and ovarian cancer
  • A man in the family is diagnosed with breast cancer
  • Having Ashkenazi Jewish ancestry
  • Triple negative or bilateral breast cancer in the family
  • One or more family members has a known HBOC mutation

Hereditary Gastrointestinal (GI) Cancer Syndromes

There are a number of inherited gene mutations that can increase the risk of cancers affecting the GI tract, including Lynch syndrome (MLH1, MSH2, MSH6, PMS2, EPCAM) and hereditary polyposis syndromes (eg, APC, MUYTH). 

Diagnosis of these syndromes is important because affected individuals and their family members can be offered life-saving screening, risk-reducing surgeries, and other therapies.

Factors that may indicate a risk of hereditary GI cancer syndromes include:

  • Lynch syndrome–associated cancers (eg, colorectal, endometrial, gastric, ovarian), especially if more than one cancer or under age 50 years
  • One or more relatives with Lynch syndrome–associated cancers, especially if more than one cancer in the same individual or if the cancer occurs under age 50 years
  • Personal or family history of multiple (10) colorectal polyps (adenomatous, hamartomatous, juvenile, or serrated polyps)
  • Known Lynch or hereditary polyposis syndrome mutations in the family.

Hereditary Cancer Support can connect you with medical genetic testing for thousands of genetic mutations associated with hereditary cancer from the comfort of your own home. Take our risk quiz to see if you may benefit from genetic testing for hereditary cancer.