Multidisciplinary Management of HER2+ Breast Cancer - Episode 4

Radiation Therapy for HER2+ De Novo MBC

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Radiation oncologist Kamran Ahmed, MD, comments on indications for using radiation therapy to treat patients with HER2-positive de novo metastatic breast cancer.

Sara A. Hurvitz, MD: You did ultimately present to a radiation oncologist. Before you tell us about your therapy and how you tolerated it, I want to ask Dr Ahmed to talk to us about the indications for radiation in somebody with de novo metastatic breast cancer. If you could, speak to the features of this case and how you might approach it in somebody who’s starting systemic therapy for widespread metastatic disease but also with painful bone metastases.

Kamran Ahmed, MD: It’s common for us to deliver radiation therapy in this stage IV setting when there are areas of pain being caused by sites of bone metastases. That’s what we’ve traditionally thought of as palliative radiation therapy. But now as systemic agents are improving, we’re noticing the greater importance of improving local control with radiation therapy as well. In addition to the palliative effects of improvement in pain control, local control is becoming an increasing reason to deliver radiation therapy. There have been a couple of important trials, namely the SABR-COMET study, which was published by David Palma out of Toronto [Ontario, Canada], which showed that there was improvement in terms of overall survival and progression-free survival in patients who received stereotactic body radiation therapy or focal radiation therapy to 1 to 5 sites of metastases. This wasn’t a study that was meant to enroll patients only with breast cancer. About 20% of patients in that study had breast cancer. There’s another study ongoing, the NRG-BR002 study, specifically looking at patients with breast cancer, but more and more we’re delivering radiation therapy for the purposes of improved local control.

Sara A. Hurvitz, MD: Thank you. The SABR-COMET study is notable because I’ve noticed that few trials have randomized patients to do SBRT [stereotactic body radiation therapy] or radiation vs systemic therapy alone. I congratulate the trial list for that design, which is risky. You’re risking that there’s no benefit, but they found a benefit. As you mentioned, the downside is that it was just a handful of patients with breast cancer. I’m excited to see the NRG-BR002 data because this remains a very open question. Of course, we don’t want to radiate a patient too much if it’s not for palliative reasons, but it’s critical for us to gather these data to help us decide how to move forward. Erika, can you talk to us about the radiation you received and how you responded to it?

Erika Rich: I responded well to it. I received 6 rounds of direct radiation to my right hip, and I was diagnosed with arthritis at the same time I was diagnosed with my metastasis, so had to also be wary of that. Five days in a row and I off on the weekend, and then I came back in for my last rounds. I did well through it. Didn’t really notice any adverse effects, didn’t have any redness on my skin, and pain went away pretty quickly. I’m not a fan of pain medications, and I had to use it only once during that sixth course of receiving treatment, so it went well.

Sara A. Hurvitz, MD: Did you receive the radiation concurrently with the THP [trastuzumab, pertuzumab, docetaxel] chemotherapy, before you started it, or after you’d had it? What was the timing?

Erika Rich: Off the top of my head, I want to say that I did them both at the same time, because whenever I got to Pittsburgh [Pennsylvania], it was very sudden. I got my port in, and I started chemotherapy on the same day. I imagine that I started radiation in that break that I had.

Sara A. Hurvitz, MD: It was right around the same time. Once you completed about 6 rounds of the docetaxel chemotherapy, you dropped the chemotherapy portion and continued the HER2-targeted therapy. Is that correct?

Erika Rich: Correct. I did that for a few months.

Sara A. Hurvitz, MD: Did you do the trastuzumab with the pertuzumab, or did you just receive the trastuzumab?

Erika Rich: Sorry, I’ve had that regularly.

Sara A. Hurvitz, MD: It’s OK. You don’t need to know. We’re getting into the nitty-gritty.

Erika Rich: I believe I just took the chemotherapy agent and did the 2 HER2-targeted therapies.

Sara A. Hurvitz, MD: That sounds very standard. It sounds like you got very good care at your facility.

Transcript edited for clarity.