It has been well established that while the majority of ovarian cancers arise sporadically, up to 20% are considered to be hereditary. Mutations in the BRCA1 and BRCA2 genes provide an explanation in many of these hereditary cases, but not all suggestive personal and family histories are explained by BRCA1/2. As our awareness of additional ovarian-cancer susceptibility genes continues to grow, the scope of available genetic testing has also begun to expand.
In honor of Ovarian Cancer Awareness month, our genetic counselors felt it worthwhile to shine a light on the current state of genetic testing and counseling for ovarian cancer. Laboratories now offer NextGeneration cancer panel genetic tests that allow for the evaluation of multiple cancer susceptibility genes simultaneously. Some of the genes available for testing are associated with well-categorized ovarian cancer risks (e.g. BRCA1/2, Lynch syndrome genes) while others are currently less well understood (e.g. PALB2, BARD1, BRIP1). In most instances, these genes are believed to be associated with increased risks for other cancer types as well.
As testing options broaden and increase in complexity, it has become increasingly important for patients to be counseled about both the benefits and limitations of genetic testing. Given the wide range of information available via cancer panels and the large volume of genes available for testing, our counselors strive to highlight a number of specific points when meeting with patients prior to testing: the ways in which a positive test result may or may not impact the patient’s care, the limitations of identifying a negative test result in the context of a suggestive personal and/or family history, and the heightened likelihood of identifying an uncertain test result as greater volumes of genetic information are analyzed.
In some instances, panel genetic testing can create additional nuance by identifying a harmful mutation in a less-well understood or “low to moderate-risk” gene. In these cases, it is important to caution patients that this positive test result may not be the sole explanation for their personal and/or family history of cancer; additional cancer susceptibility genes may be contributing and they should inform their counselor of any changes to their history as this may alter recommendations for additional genetic testing in the future.
Our genetic counselors believe that understanding a patient’s comfort with the benefits and limitations of testing as well as their primary motivation for testing is essential. This process enables our counselors to personalize testing in an effort to maximize the likelihood the patient’s goals will be satisfied (regardless of whether results are positive or negative), while minimizing the opportunity for the patient to receive an uncertain or uninformative test result.