Kim McGreevy, MS, CGC, Certified Genetic Counselor
The Chester County Hospital and Health System
Published: July 26, 2013
It is estimated that approximately 5-10% of women who develop breast cancer and approximately 10% of women who develop ovarian cancer have inherited an alteration, or mutation, in one of their genes that predisposes them to these cancers. The most common genes that predispose to breast and ovarian cancers are the BRCA 1 and BRCA 2 genes. The BRCA genes and the potential of genetic counseling have been in the spotlight lately since actress Angelina Jolie wrote a New York Times op-ed piece entitled "My Medical Choice." Jolie announced that she carried a "faulty" BRCA 1 gene, placing her at a significantly increased risk to develop breast and ovarian cancer.*
All men and women have two copies of the BRCA 1 and BRCA 2 genes. One copy of the gene is inherited from each biological parent. The BRCA 1 and BRCA 2 genes are called "tumor suppressor genes" and help prevent cancers from developing from a single cell. However, some people are born with a mutation in one of these genes that causes it to not work properly. These individuals have a significantly increased risk to develop cancers, mainly breast and ovarian cancers, and these cancers typically occur at younger ages (under age 50).
Mutations in the BRCA 1 and BRCA 2 genes run in families and are passed on from generation to generation. Genetic testing for the BRCA 1 and BRCA 2 genes can be performed using a blood sample and can determine if an individual carries a mutation in one of these genes. Not every individual who has a personal and/or family history of cancer needs to consider genetic testing.
Cancer genetic counselors are medical professionals who specialize in hereditary cancer conditions and can help determine if genetic testing is appropriate. If testing is appropriate and performed, the genetic counselor can assist with interpreting the results and can recommend cancer screenings and preventative actions based on guidelines established by the National Comprehensive Cancer Network (NCCN).
Individuals concerned about their personal and/or family history of cancer may benefit from cancer genetic counseling. The following are indications for cancer genetic counseling:
- Individuals diagnosed with cancer at an early age (younger than 50);
- Women who have been diagnosed with ovarian cancer at any age;
- Individuals with two or more close relatives on the same side of the family with the same or related types of cancer (for instance breast and ovarian cancer, or colon and uterine cancer);
- Individuals who have had more than one primary type of cancer (bilateral breast cancer or women with both breast and ovarian cancer);
- Individuals who have a family member who has been found to carry a mutation in a cancer predisposition gene;
- Individuals of ethnicities that are known to have a higher risk to carry mutations in the BRCA 1 and BRCA 2 genes (Ashkenazi Jewish).
Cancer genetic counselors are able to help educate patients about hereditary cancer conditions, interpret genetic testing results, and discuss options for cancer screening and prevention according to guidelines established by the NCCN.
*In a New York Times op-ed piece entitled "My Medical Choice," actress Angelina Jolie announced that she was found to carry a "faulty" BRCA 1 gene, which places her at a significantly increased risk to develop breast and ovarian cancer. In this piece, Jolie discussed her personal experience of losing her mother to ovarian cancer at the age of 56 and her decision to undergo a prophylactic (preventive) mastectomy to reduce her breast cancer risks. Jolie indicated to other sources that she also plans to undergo a prophylactic salpingo-oophorectomy to remove her ovaries and fallopian tubes in order to reduce her risks of ovarian and fallopian tube carcinomas.
This article was published as part of the Daily Local News Medical Column series which appears every Monday. It has been reprinted by permission of the Daily Local News.