Genetic Testing for Ovarian Cancer Patients is Underused

Genetic Testing for Ovarian Cancer Patients is Underused
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Patients with ovarian cancer are not getting all the testing they need, according to study a recently published in Journal of Clinical Oncology.

Breast and ovarian cancer testing has become more complicated over the years, and recommended for more types of patients. The question these researchers asked was “Is practice keeping up with the guidelines?” An important issue since ovarian cancer, in particular,  causes more deaths annually than any other female reproductive system cancer.

Researchers from multiple institutions studied 83,000 women age 20 years and older with breast and ovarian cancer who were diagnosed in California and Georgia during 2013 and 2014. The study included 77,085 breast cancer patients and 6001 with ovarian cancer. It is the largest study of its kind to date.

For the analysis, data from the National Cancer Institute Surveillance Epidemiology and End Results (SEER) Program were linked to results from four laboratories that performed nearly all germline cancer genetic testing in those states. SEER tracks cancer diagnoses and outcomes in large populations across the United States. Testing use and results were analyzed at the gene level.

The researchers found that actual testing did not always meet national guidelines (i.e. Standards and Guidelines for the Interpretation of Sequence Variants: Joint Consensus Recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology ). Fewer than a quarter of breast cancer patients and a third of ovarian cancer patients diagnosed during that period in the two states underwent genetic testing for cancer-associated mutations.

“We wanted to see what cancer genetic testing and results looked like in the real world,” said Allison Kurian, M.D., M.Sc., lead author and associate professor of medicine and of health research and policy at Stanford. “Now we can see that women with ovarian cancer are dramatically undertested. We also learned that between 8% and 15% of women with breast or ovarian cancer carry cancer-associated mutations that could be used to drive care decisions and influence family members’ healthcare and screening choices.”

The BRCA1 and BRCA2 tests for predisposition to breast and ovarian cancer were among the first to reach the clinic. Initially, these tests where used to determine risk, but they now can also be used to guide treatment. The 2015 approval of the first poly (adenosine diphosphate-ribose) polymerase inhibitor (PARPi; olaparib, Lynparza) for platinum-sensitive, relapsed, high-grade ovarian cancer with either germline or somatic BRCA1/2 deleterious mutations changed how BRCA1/2 testing services were used for such patients. Genetic testing is now used in ovarian cancer patients for risk assessment and/or to guide treatment, and irrespective of a family history of breast or ovarian cancer.

Kurian and her colleagues also found significant disparities in who is most likely to receive testing. The rate of genetic testing for ovarian cancer was lower among black patients (21.6%) compared with white patients (33.8%) and lower among patients without insurance (20.8%) compared with patients with insurance (35.3%). In areas where residential poverty was at least 20%, testing prevalence was only about 20% compared with about 38% among patients living where the poverty level was less than 10%.

“Substantial testing gaps and disparities among patients with ovarian cancer are targets for improvement,” the authors concluded.

Kurian’s co-authors were Kevin Ward, Ph.D., M.P.H., assistant professor in epidemiology at Emory University. Lynne Penberthy, M.D., M.P.H., associate director for the National Cancer Institute’s Surveillance Research Program, and Steven Katz, M.D., M.P.H., professor of medicine and of health management and policy at the University of Michigan, are co-senior authors.