Genetic testing for breast cancer
Only about 5 – 10 percent of breast cancer is "hereditary," meaning a result of a genetic change known as a mutation. While mutations in the BRCA1 and BRCA2 genes are the most common causes of hereditary breast cancer, several other genes may also play a role in developing breast cancer.
Genetic testing for breast cancer may be appropriate if your personal or family history includes the following:
- Breast cancer diagnosis at age 45 or younger
- Ovarian, fallopian tube or primary peritoneal cancer at any age
- More than one breast or ovarian cancer in the same person
- Male breast cancer at any age
- Three or more family members with breast, ovarian, pancreatic or prostate cancer
- Breast, uterine and thyroid cancer in the same side of the family
- Breast, ovarian or pancreatic cancer in a family with Ashkenazi Jewish ancestry
Genetic testing for ovarian cancer
Most ovarian cancer is not hereditary – only 15 to 20 percent of cases are due to inherited gene mutations. Hereditary Breast and Ovarian Cancer Syndrome can increase the risk of breast, ovarian, pancreatic and prostate cancer. Lynch syndrome raises the risk of developing colon, endometrial, renal and gastrointestinal cancers. Ovarian cancer may also be caused by other mutated genes that have yet to be identified.
Genetic testing for ovarian cancer may be appropriate if your personal or family history includes the following:
- Ovarian cancer at any age
- More than one cancer – uterine, breast or thyroid – in the same person
- Three or more family members with ovarian, uterine, breast or colorectal cancer
Genetic testing for colorectal cancer
Approximately 5 to 10 percent of all colorectal cancers are caused by an inherited gene mutation. There are two major types of hereditary colon cancer: Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer, and one that is associated with the development of an unusual amount or type of polyps. Colorectal cancer may also be caused by other mutated genes that have yet to be identified.
Genetic testing for colorectal cancer may be appropriate if your personal or family history includes the following:
- Colorectal or uterine cancer diagnosed younger than age 50
- Two separate colorectal cancers or colorectal and uterine cancer in the same person
- Three or more family members with colorectal, uterine, ovarian or stomach cancer
- Ten or more colorectal polyps during a lifetime
Genetic testing for prostate cancer
Approximately 5 to 10 percent of all prostate cancers are considered to be hereditary.
A man with a first degree relative – a father or brother – diagnosed with prostate cancer is twice as likely to develop the disease as a man with no family history of it. If two close male relatives have had prostate cancer, a manâ€™s lifetime risk of developing the disease is increased five-fold.
Men with mutations in the BRCA1, BRCA2, CHEK2 and HOXB13 genes are at an increased risk for prostate cancer.