Ovarian cancer can be — but isn’t always — hereditary. The grand majority (about 76-80%) of ovarian cancer is not hereditary and is actually sporadic, meaning that its occurrence is influenced by age, environment and lifestyle choices.
Because a significant amount of invasive ovarian cancer cases (up to 24%) are due to hereditary cause, it’s recommended that all women with invasive ovarian cancer are offered genetic counseling and genetic testing.
What type of genetic testing are women with invasive ovarian cancer offered?
Minimally, a woman with invasive ovarian cancer should be offered genetic testing for BRCA1 and BRCA2 mutations. Approximately 11% of women with invasive ovarian cancer will have a BRCA1 mutation and 7% will have a BRCA2 mutation.
While BRCA mutations make up the majority of the known hereditary causes for ovarian cancer, there are other genetic causes as well. About 1% of women with invasive ovarian cancer will have a condition called Lynch syndrome, caused by a mutation in one of five genes. Depending on that gene, there may be an increased risk for colorectal, stomach, ovarian, endometrial and other cancers.
Additionally, we know 5% of the time a woman with invasive ovarian cancer will test positive for a gene mutation other than BRCA1, BRCA2, or the Lynch syndrome genes. These “other genes” are newly described meaning that they’ve always been in our bodies, but that we are just starting to learn about them. Therefore, we may not have as much information about them in regards to risks and recommendations for medical management. Additionally, it is possible that there could be a gene related to ovarian cancer that we have not found yet and are unable to test for.
How does genetic testing work?
We can do genetic testing in the form of gene panel that would look at many genes at once. This gene panel could include BRCA1, BRCA2, the Lynch syndrome genes, as well as the “other” gene category. This panel generally has a similar cost when compared to BRCA1 and BRCA2 testing alone. A licensed genetic counselor can discuss insurance coverage for all of the different genetic testing options.
If the woman who had or has ovarian cancer is able to have her own genetic testing, she is the best candidate to start with before moving on to first degree relatives (parents, siblings, and children) and second degree relatives (grandparents, aunts and nieces). However, if the woman who had ovarian cancer is deceased, doesn’t want genetic testing or is unable to have genetic testing, then we may consider ordering genetic testing for a first or second degree relative.
What comes next?
If genetic testing identifies a mutation in a gene, we can offer genetic testing to other family members to see if they are also at risk for a certain type or types of cancer. If we know who is at risk in the family, we can change their medical management to either prevent or catch a cancer early. This may mean recommending a breast MRI in addition to a mammogram or recommending more frequent colonoscopies. In some instances, surgical risk-reduction might be appropriate. (Click here to learn more about surgical options specific to ovarian cancer.)
Additionally, if we know who isn’t at high risk for developing cancer, we can treat them as we would someone in the general population. They wouldn’t need extra screenings or preventive surgeries and could just follow general population guidelines for cancer screening.
If you’d like more information about ProMedica Cancer Institute’s Cancer Genetics Program, please call 419-824-5073.
Sarah Adelsperger, MS, LCGC, is one of only two licensed and board-certified genetics counselors specializing in cancer in northwest Ohio and southeast Michigan. Sarah joined Kelly Morse, MS, LCGC, in the Cancer Genetics Program in May 2015 at ProMedica Cancer Institute.