Identifying Ovarian Cancer Patients for PARP Inhibitors

Criteria to Consider

• Selective strategy may include approaches such as somatic testing, germline testing or HDR testing
• When it comes to HRD testing, Dr. Stephanie Wethington suggests the Myriad assay
• Only 34% of women with ovarian cancer are getting germline genetic testing, according to a study published in the Journal of Clinical Oncology

How to determine which ovarian cancer patients will benefit most from PARP inhibitors such as olaparib (brand name: Lynparza) is still a big question in oncology. “If you’re going to use a selective strategy to identify patients for PARP inhibitors, there are different approaches, different pathways,” says Dr. Stephanie Wethington, director of The Susan L. Burgert M.D. Gynecologic Oncology Survivorship Program and assistant professor in the Department of Gynecology and Obstetrics at Johns Hopkins Medicine. “Some people will start with the somatic testing first and then move to germline or HRD. Some will start with a germline in HRD assay. Some start with the germline, then the somatic, and then the HRD.”

Regardless of the sequence, Dr. Wethington says that one of the big questions she’s often asked when she’s co-managing patients with medical oncologists is which specific HRD assays to order, given that there is variation in the assays and how well they correlate with clinical outcomes. Oncologists want to know whether they should order Foundation or Caris or an in-house test or Myriad My Choice. “Certainly in many of the clinical trials, the assay for HRD that they’ve used is the Myriad assay,” she says. “If one is to be very specific and particular in order to understand the HRD results and how they relate to response, that would be the assay that is needed.”

But the germline testing is also crucial, not just for determining course of treatment, but also so patients can give the results to their family. “So their family knows whether or not they need testing,” she says. “That’s the best prevention that we have for this disease.” Currently about one-third of women with epithelial ovarian cancer are getting germline genetic testing, according to the results of a study published in the Journal of Clinical Oncology. “And I think that is one area where you have the potential to impact individuals and their survival through prevention.”