As researchers learn more, the percentage of ovarian cancer known to be hereditary is steadily growing. Although not yet a medical recommendation in most regions, many medical professionals suggest that anyone with an ovarian cancer diagnoses receive genetic testing. This is because it may change the treatment course and other family members will need the information to make decisions about their health. Recently, new chemotherapy drugs have been approved or are in clinical trial that are specifically designed for hereditary ovarian cancer.
Hereditary cancer is a relatively new science. In the not too distant past, genetic services only tested for BRCA gene mutations. Today, many additional risky genes have been discovered and more are expected to be discovered. Those with a family history of cancer who in the past received a negative result for BRCA gene mutations may want to consider being re-tested with a more comprehensive gene panel. This also goes for those returning a negative result with today's gene panels who may want to revisit genetic testing in a few years when more genes have been added. As an an example, the RECQL gene was discovered in 2015, but does not yet appear on the above list. Based on his research, Dr. Mohammad Akbari from Women’s College Hospital believes RECQL mutations are as dangerous as in the BRCA genes.
Genetic testing usually consists of a blood or saliva test. Genetic testing may be done once a person reaches 18 years of age, but screening and prevention options are usually not recommended until at least the age of 25. Wait times for genetic test results vary, depending on the type of service used. Government-insured services tend to have longer wait times. The wait leading up to testing and for results can be very stressful. Make sure you are supported during this process. Consider having someone with you when you receive the results who can take notes and be a support in the case of a positive result.
Most health care systems will provide coverage for the cost of genetic testing where certain criteria apply (see Red Flags). If you do not qualify for government-insured genetic testing or are not comfortable with the wait times, there are private clinic and online alternatives if you are willing to pay for them. Regardless of the option you choose, it is essential that a professional genetic counselling session be included.
Consumers must be well-educated to choose the best fit for them. The first thing to be aware of is that not all genetic tests are created equal. The type of test needed is dependent on the circumstances and on how comprehensive you wish the test to be. Do you want to be tested for all the risky genes that have been discovered to date? Has a mutation already been identified in your family? Are you of Ashkenazi Jewish decent or of one of the other ethnic groups that experiences a higher rate of HBOC syndrome?
Multi-gene panel tests
Panel tests look for mutations across several genes at the same time, giving you a good snapshot of your broader risk for various cancers and health conditions. It is important to know that the multi-gene panel test may identify other cancer risks that weren’t previously on your radar. So, if you don't want that information, that must be conveyed.
Historically, genetic testing has focused on examining one gene at a time. If your first single-gene test didn’t find a mutation, your healthcare provider or genetic counsellor may order follow-up tests for a different gene (or genes). With the advent of multi-gene panels this process is becoming less frequent.
If you have a family history of a mutation in one gene, a single-site test may be the best option for you. This type of test looks for the specific mutation that’s already been identified. Because it’s only looking for one mutation, this test may be less expensive and results may come quicker.
If you are of Ashkenazi Jewish ancestry, a single-site test for the three common founder BRCA1/2 mutations may be especially helpful.
Getting the Right Test
Work closely with your healthcare provider or a genetic counsellor to understand which test is best, given your situation. If you’re uncomfortable with the type of test being suggested to you, keep asking questions and expressing your concerns until you feel satisfied or contact us for more information. Over 1,200 mutations have been discovered to date in each of the BRCA genes alone. Some of these mutations do not increase cancer risk. In all cases, it is essential a genetics professional interpret the results.
Ensure the test you choose includes a genetic counselling session by a professional. DO NOT let your doctor interpret the results
If you do not fit the family history criteria for government-insured genetic testing, there are affordable, no-barrier options available that can be ordered through a private clinic or online through your doctor
Do your homework to ensure you have chosen the genetic test that is right for you
Proponents of widespread testing, also known as population testing, believe current guidelines ignore the fact that the genetic predisposition to cancer can be hidden in families. This is because an inherited mutation can be passed down not only by females, but also by males who tend to present with less cancer than females. For this reason, reliance on family medical history may not be enough.
Dr. Mary-Claire King, who first discovered hereditary breast cancer, believes that too many carriers are being missed due to the restrictive criteria for insurance-paid services. This has basis in an increasing body of evidence. Dr. King’s own research reported about 50% of the study group who were diagnosed with breast cancer and were BRCA positive did not have a close family history of cancer. Dr. Steven Narod, world leader in hereditary breast cancer genetics, and his team have tested thousands of women in Ontario, most who do not have a family connection to breast or ovarian cancer. His research has shown that fewer than half of the Jewish women that have been found to carry BRCA mutations would not have qualified for government-insured genetic testing.
Dr. King serves as an unpaid scientific advisor to Color Genomics, an affordable, no-barrier, full-gene-panel service now available in Canada that includes genetic counselling. If you would like to learn more, contact us.