Understanding inherited cancers and genetic testing
2/11/2021 by Denise Dupras, M.D., Ph.D.
Cancer results when the growth of cells becomes uncontrolled. Genes, which are the controllers of cell growth, can be damaged after birth or inherited with problems that prevent them from working correctly. These genes, which can be inherited from either parent, are called inherited cancers. But they cause only about 5%–20% of cancers.
As a patient, you may wonder whether you should worry if a family member has cancer. An important clue to an inherited cancer is family history.
Answering these questions and discussing them with your health care provider is important:
- Who has cancer? For example, consider siblings, parents, grandparents, aunts and uncles.
- What kind of cancer did they have?
- How old were they when they had cancer?
Some groups of cancers seem to be inherited together and are understood, including the gene that is involved. Two of the most recognized genes are BRCA1 and BRCA2, which increase the risk of breast and ovarian cancer in women. This genetic information led to Angelina Jolie to have surgery to remove both of her breasts. Less well-known is that this gene abnormality increases the risk of cancer in men, too.
It is important to review your family history and talk to your primary care provider if you think you may be at risk for an inherited cancer. Your provider can help you decide if getting genetic testing is a good idea.
What if genetic testing is positive?
Not everyone with an abnormal gene gets cancer, but genetic testing may change how often your health care provider recommends that you get checked for cancer or if you need treatment to decrease your risk of getting cancer in the future.
Less than 1 in 5 cancers results from an inherited cancer condition, and the best way for you to determine if you might have increased risk related to your genes is to look at your family history.
Denise Dupras, M.D., Ph.D., is a general internist in the Division of Community Internal Medicine. She completed her medical and doctoral degrees at Mayo Clinic Alix School of Medicine and her residency in internal medicine at Mayo Clinic in Rochester. Her interests include medical education and evidence-based medicine.