Case 4: BRCA+ Metastatic Breast Cancer

Hope Rugo, MD, FASCO: Dr Adam Brufsky will present our next case on a patient who has metastatic triple-negative breast cancer who tests positive for a germline BRCA mutation. Then he’ll talk about some of the newer data, and we’ll discuss it as a panel.

Adam Brufsky, MD, PhD: This is a 37-year-old woman who presented with a palpable breast mass and mild back pain. This was poorly differentiated infiltrating ductal carcinoma that was ER 0, PR 0, and HER2 0. She had a staging PET/CT that showed FDG [fluorodeoxyglucose]-avid lesions in the bone, lung, and mediastinal nodes. Her labs were normal, except for a slightly elevated alkaline phosphatase. Biopsy of the lung metastases showed metastatic disease. PD-L1 was 0% by the Ventana [PD-L1 (SP142)] Assay, and germline testing was positive for a BRCA1 pathologic variant.

Hope Rugo, MD, FASCO: For this patient, what we do next has to do with whether or not we have results from genetic testing. So if you have a patient like this, do you routinely refer the patient for genetic testing up front? Does that influence your treatment choices? Do you go back over your patients who have metastatic disease who didn’t have testing because it was before PARP [poly ADP ribose polymerase] inhibitors? Ian, what do you do in this setting?

Ian Krop, MD, PhD: I think given the data and the benefits of PARP inhibitors, we are doing our best to get all of our metastatic patients tested. That’s true even if they’re not first-line patients. Here is a drug that has clear benefit and is relatively well tolerated, so it’s important that patients know it’s an option. So testing is really important.

Hope Rugo, MD, FASCO: Adam, do you usually send the broader panels when you send it? You don’t just do BRCA1 and BRCA2?

Adam Brufsky, MD, PhD: We send the broader panel. It’s rare now to just do BRCA1 or BRCA2. I don’t remember off the top of my head which panel. We have a 9-gene panel, an 11-gene panel, and a 20-gene panel. So one of those.

Hope Rugo, MD, FASCO: As studies are now trying to use PARP inhibitors and see how they work in patients who have other DNA repair defects that are less common, it is, I think, increasingly important to us. Evita, do you send the test out? I don’t know how involved you are with testing for BRCA, but of course for all of us, these are send-out tests. Is your pathology department involved in that, or does that go through the genetic counselors?

Evita Sadimin, MD: They are a send-out test for us, and there are different ways that they get requested. Sometimes, they get requested through the genetic counselor. Sometimes, just from the patient history and directly from the clinician.

Hope Rugo, MD, FASCO: It’s an interesting time. As we’ve had PARP inhibitors approved, the genetic counselors have been overwhelmed and a lot more studies are looking at direct consumer testing. The oncologist talks to the patient as opposed to the genetic counselor. Do you usually refer your patients to a genetic counselor, Ian?

Ian Krop, MD, PhD: We do. They’re doing most of it by phone these days, but even before the COVID-19 [coronavirus disease 2019] situation, they were moving toward that because their volume is going up. But yes, we still go through a genetic counselor for our patients to get tested.

Hope Rugo, MD, FASCO: Adam, how about you?

Adam Brufsky, MD, PhD: We do, but as you know the genetic counselors can be somewhat overwhelmed. And so I think that it’s really going to be a debate. We really try to send patients to the genetic counselor and do it in that context when we can. That’s what occurs for the vast majority of our patients.

Transcript edited for clarity.