The last decade has produced amazing advances in our understanding of the genetic risk factors for ovarian cancer. Of the one in 70 women who will develop ovarian cancer in their lifetime, 20 to 25 percent are the result of a major genetic cause. This means that of the 22,000 new diagnoses of ovarian cancer expected in the US in 2014, over 5,000 may be associated with an underlying hereditary cancer syndrome.
Hereditary Breast and Ovarian Cancer syndrome (HBOC) is the most common cause of inherited ovarian cancer risk. HBOC is due to changes (mutations) in the BRCA1 and BRCA2 genes (BRCA1/2). In families where a BRCA1/2 mutation is present, there may be early-onset breast cancer, ovarian cancer, and sometimes melanoma, pancreatic or prostate cancer. Several individuals on one side of the family (either mother or father’s side) in more than one generation may be affected. For women who inherit a BRCA1/2 mutation, the lifetime risk for ovarian cancer is 20 to 40 percent, in contrast to the general population risk of less than two percent. These women also have greatly increased chance of developing breast cancer (50 to 80 percent by age 70), which often occurs at a young age.
For a patient who has ovarian cancer, genetic counseling and testing can be very important. First, there are promising new treatments in the final stages of research that are especially effective in women with a BRCA1/2-related ovarian cancer. Second, each of this individual’s children and siblings have a one in two or 50-percent chance to have inherited the same BRCA1/2 mutation. For a woman who has a BRCA1/2 mutation, increased screening and risk-reducing options are available. Several studies have shown that these special management strategies can dramatically reduce her risk to develop breast or ovarian cancer, and may save her life. For family members who do not carry the BRCA1/2 mutation, their risks are considered the same as in the general population.
HBOC is just one of the known inherited causes of ovarian cancer. There are several other hereditary cancer syndromes associated with an increased risk for ovarian, as well as other cancers such as colon, uterine, brain, stomach, pancreatic, adrenal and leukemias. Because up to one-quarter of all ovarian cancers have an underlying genetic cause, it is now being recommended that all women with this diagnosis be offered cancer genetic services.
If you, or someone in your family has ovarian cancer, you should collect as much information as possible about any other cancers in your family. Bring this information to your doctor, and request a consultation with a cancer genetics professional. Understanding your genetic risk for ovarian cancer can be a powerful tool in the fight against this deadly disease.
Qualified cancer genetics professionals can be located at the following sites:
- Emory Clinic’s Department of Human Genetics
- National Society of Genetic Counselors
- National Cancer Institute’s Cancer Information Service
About Cecelia Bellcross, PhD, MS, CGC
Cecelia Bellcross, PhD, MS, CGC, is an Assistant Professor with the Department of Human Genetics, Emory University School of Medicine, where she developed and is Director of the new Emory Genetic Counseling Training Program. Her areas of interest and expertise include hereditary cancer and translational genomics. She obtained her Master of Science degree in Medical Genetics through the University of Wisconsin-Madison Genetic Counseling program in 1990, and her Ph.D. from the U.W.-Madison Department of Population Health Sciences in 2007. Dr. Bellcross received her certification from the American Board of Genetic Counseling (ABGC) in 1993, and recently served on the Accreditation Council for Genetic Counseling.