Rates of genetic testing in ovarian cancer “remain well below the goal of universal testing,” according to authors of a systematic review and meta-analysis published in Gynecologic Oncology.1
The researchers analyzed data from 35 studies to determine rates of germline genetic testing in patients with ovarian cancer and identified factors that influence whether patients are being tested or not.
“For many years now, the recommendation from multiple organizations, including the Society of Gynecologic Oncology, has been for universal genetic assessment of women with ovarian cancer,” said review author Melissa Frey, MD, an assistant professor of obstetrics and gynecology at Weill Cornell Medicine in New York, New York.
“But we also knew that, despite the recommendation for universal testing, in reality, many people don’t have access to testing or don’t have testing recommended to them,” Dr Frey added.
With this in mind, she and her colleagues conducted a systematic review of the literature, leading to a meta-analysis of 35 studies, 15 from the United States and 20 from 8 other countries.
Collectively, the studies included 16,891 patients with ovarian cancer who were a median age of 60.5 years at diagnosis.
Of the 35 studies, 19 reported on the use of genetic services without any intervention, 7 studies did involve an intervention, and 9 studies included scenarios with and without interventions.
In the cases without any intervention, 39% of patients were referred for genetic counseling, and 30% of patients completed genetic testing.
Importance of Genetic Testing
According to Dr Frey, approximately 15% to 20% of patients with ovarian cancer will carry a germline hereditary mutation associated with a substantially increased risk. Most mutations are in BRCA1 or BRCA2, but a minority of patients will have rarer mutations in genes such as RAD51C and RAD51D.
In the review, 26 studies that reported genetic testing results revealed a pathogenic variant in 24% of patients.
“When I think about the downstream implications of genetic testing, the first, most pertinent thing is individualized or targeted therapy for the person who’s getting a genetic test, who has a diagnosis of ovarian cancer,” Dr Frey said.
Although poly adenosine diphosphate-ribose polymerase (PARP) inhibitors are used to treat ovarian cancer with and without hereditary mutations, PARP inhibitors are particularly effective in patients with BRCA1/2 mutations. Therefore, identification of hereditary mutations can help to stratify treatment regimens.
Another implication of genetic testing is the risk of other cancers, such as breast cancer, in people carrying these hereditary mutations, which will influence future screening and surveillance. Family members potentially carrying the same genetic mutation is also a consideration.
“We know that all first-degree relatives have a 50% chance of carrying the same mutation, and all second-degree relatives will have a 25% chance of carrying the mutation,” Dr Frey said. “So if we diagnose a BRCA mutation in a patient, and her sibling or her parent gets tested, that certainly can save that person’s life by giving them the opportunity for genetically tailored disease prevention.”
Cost as a Barrier to Testing
In their review, Dr Frey and colleagues looked at the different metrics and characteristics of patients who did or did not undergo genetic testing.
One finding was that 23% of uninsured patients had undergone genetic testing, compared with 38% of patients who had medical insurance.
“I think physicians and patients are very worried about cost as a barrier to genetic assessment,” Dr Frey said. “About 10 years ago, genetic testing was often in the range of several thousands of dollars. But now, even if someone did pay out of pocket, the most they would be charged by many of the testing companies would be about $250.”
Dr Frey noted that insurance plans often cover genetic testing completely.
However, along with getting tested, providers recommend additional support from genetic counseling services, which can come with a considerable cost and are currently in short supply in the United States.