Dr. Penson on Biomarkers of Response to PARP Inhibitors in Ovarian Cancer

Richard T. Penson, MD, MRCP, associate professor, Harvard Medical School, and clinical director, Medical Gynecologic Oncology, Medicine, Massachusetts General Hospital, discusses prospective biomarkers that may predict response to PARP inhibitors in advanced ovarian cancer.

One-third of BRCA mutations are somatic, says Penson. Because somatic mutations are not inherited, they are not as commonly tested for. However, there has been a steady uptick of tissue tests in addition to germline testing in the blood or saliva, adds Penson.

About half of high-grade serious endometrioid tumors harbor homologous recombination deficiency (HRD) which is another important marker to look for.

Lastly, the field is evaluating a new generation of assays that will identify optimal combination therapies, says Penson. Approximately 20% to 30% of patients who harbor a BRCA mutation will acquire a reversion mutation. As such, assays that can help determine a combination that has the potential to overcome this resistance will be important, concludes Penson.