What Type of Cancers can you Genetic Test for?
Cancer falls into three general categories: Sporadic, Familial, and Hereditary. The majority of cancer is sporadic (65%) and has no known cause. Many different factors can contribute to whether or not someone gets cancer. Sometimes people in the same family share similar risk factors with each other. When this occurs cancer can affect multiple individuals in the same family and is referred to as familial cancer (25-30% of cancer). Only 5-10% of all cancer is considered hereditary. Hereditary cancer is often caused by a single change in a single gene associated with cancer. A person who inherits this change has a hereditary cancer syndrome and is at an increased risk of developing particular cancers. There are many different hereditary cancer syndromes, however, the two most common are:
- Hereditary Breast and Ovarian Cancer syndrome
- Lynch syndrome
Hereditary Breast and Ovarian Cancer Syndrome
Hereditary Breast and Ovarian Cancer syndrome is caused by inherited gene changes in BRCA1 and BRCA2. Inherited changes in these genes increase the risk of breast cancer, ovarian cancer, fallopian tube cancer, pancreatic cancer, melanoma, and prostate cancer. Cancers associated with changes in these genes may occur at an unusually early age (<50).
Because BRCA1 and BRCA2 gene changes are relatively rare in the general population, genetic testing is only recommended if the person’s individual and/or family history suggests the possible presence of a BRCA gene change.
If you or anyone in your family meet any of the following criteria, it's appropriate to talk to a genetic counselor:
- Breast cancer diagnosed before age 50 years
- Cancer in both breasts (bilateral disease)
- Multiple primaties, for example, breast cancer and ovarian cancer in the same individual
- Ovarian cancer or fallopian tube cancer (any age)
- A male in the family who was diagnosed with breast cancer
- Triple negative breast cancer at or before age 60 years
- Ashkenazi Jewish ancestry and a personal and/or family history of breast cancer, ovarian cancer, or pancreatic cancer.
- Three or more relatives diagnosed at any age with breast cancer, pancreas cancer, or aggressive prostate cancer (aggressive prostate cancer has a Gleason score of 7 or higher).
Lynch syndrome, also called Hereditary Nonpolyposis Colorectal Cancer (HNPCC), is caused be a change in one of five genes: MLH1, MSH2, MSH6, PMS2, or EPCAM. A change in any of these genes increases a person’s risk of getting colon cancer, rectal cancer, endometrial (uterine) cancer, and several other cancers in the colorectal region. If you or anyone in your family meets any of the following criteria, it’s appropriate to talk to a genetic counselor:
- Known Lynch syndrome mutation in the family
- Individual diagnosed with colorectal or endometrial cancer <50y
- Individual with multiple colorectal or endometrial cancers
- Family history of three or more close relatives with colorectal or endometrial cancer at any age”