Welcome to The Breastcancer.org Podcast, the podcast that brings you the latest information on breast cancer research, treatments, side effects, and survivorship issues through expert interviews, as well as personal stories from people affected by breast cancer. Here's your host, Breastcancer.org Senior Editor, Jamie DePolo.
Jamie DePolo: Hello, I’m Jamie DePolo, senior editor at Breastcancer.org. I’m podcasting live from the 2023 San Antonio Breast Cancer Symposium.
I am here with a special guest that many of you probably know, Dr. Marisa Weiss, who is the founder and chief medical officer of Breastcancer.org. She’s also a radiation oncologist and there was a practice-changing study discussed this morning about whether some people who have a complete response in their lymph nodes to chemotherapy before surgery, they may not need lymph node radiation after surgery, and Dr. Weiss is going to talk about that with us.
Dr. Marisa Weiss: Yes. Well, thank you so much. As chief medical officer of Breastcancer.org, and NSABP B-51 study was reported today, and it’s an important study. It involves people who had lymph nodes involved upfront upon diagnosis, who then go through their upfront neoadjuvant treatment with chemotherapy, and if they have HER2-positive disease, then they also got anti-HER2 therapy, and then after their systemic treatment was over, those medicines were finished, they went ahead and had their surgery. And they looked at the pathology report and to see is there anything left in the pathology report? Were the lymph nodes clear or not?
And in general, we, in radiation oncology, treat people who have lymph nodes…positive lymph nodes upfront even if they have no cancer cells left behind in the lymph nodes at the time of surgery after their upfront chemotherapy. Not knowing if we’re really adding value, if we’re making…helping people live longer with a lower risk of recurrence or not. And so, we’ve been waiting for this study for a long time and I actually accrued and had some of my patients be…enter this study, and it took a long time for this study to get off the ground and finish.
So, this study showed that adding radiation to lymph nodes in people who had upfront lymph nodes involved and who had nothing left in the lymph nodes after their upfront treatment and at the time of surgery, that adding radiation to the lymph nodes at that point and for those people did not lead to an improvement in outcomes.
And that’s good to know because we had been treating those people with radiation even if they had a complete response and now we don’t have to treat those people in the same way.
Like these data had a follow-up of about five years or so, and it looks like there was no significant difference at that five-year mark and probably on this study it’s not just the omission of radiation -- like leaving radiation out -- because those people…a lot of those people continued to be treated.
So, it’s not like they…they’re diagnosed, they’ve got lymph nodes involved and they go through all that upfront chemotherapy with or without HER, anti-HER2 therapy, and have their surgery and there’s nothing there, a lot of those people go on to continued treatment.
So, for example for those people who have HER2-positive disease, they continue with Herceptin plus or minus Perjeta for up to a year, right? And for those people who have hormone receptor-positive disease, and who are treated up front, they’re less likely to have a complete response, but those ones who did, they’re on anti-estrogen therapy or endocrine therapy for five years, sometimes 10 years, often 10 years.
So, they are still getting protection, but from a different source. The radiation didn’t add…didn’t help them live longer with a lower risk of recurrence after they had that complete response and many of those as I said because they continued to do other things to continue to be protected and safe from breast cancer recurrence. So, it is game changing.
Jamie DePolo: I do…I want to ask you one question just to clarify because in the study that I read…
Dr. Marisa Weiss: Yeah.
Jamie DePolo: …I don’t want people to think that there was no radiation in all cases for anybody who had the response because my understanding was if somebody had a lumpectomy they still would get whole breast radiation…
Dr. Marisa Weiss: Yes.
Jamie DePolo: …they just would not get radiation to the lymph nodes…
Dr. Marisa Weiss: Right. That’s right.
Jamie DePolo: …and people who had mastectomy would not get whole breast radiation.
Dr. Marisa Weiss: Okay. So, to clarify, for people who had lymph nodes upfront and had mastectomy, they were randomized between radiation to the chest wall and lymph nodes versus no radiation at all.
Jamie DePolo: Right.
Dr. Marisa Weiss: But for those people who had lumpectomy upfront and who had positive lymph nodes, when they went to have their surgery, they had the lumpectomy, and they had the lymph node sampling, but…and they had radiation to the breast and all those people plus or minus radiation to the lymph nodes.
So, it doesn’t mean that there’s no role for radiation in people who have breast preservation therapy, it just means for the…they don’t need to have their lymph nodes treated and for the people who had mastectomy with a complete response, they did not benefit from having lymph nodes treated if they had nothing left in the lymph nodes.
Now let me say that for a lot of people who have upfront treatment, they might not have a complete response in the breast or the lymph nodes and those people still may be a candidate for, may benefit significantly from adding radiation to it.
So, we are really in this world right now of precision medicine, trying to target…give the right treatments to the right person at the right time. And so, yes, it means that in this very specific situation it looks like radiation does not seem to improve the outcomes of people who had upfront lymph node involvement and had a complete response after their upfront medicine therapy, chemotherapy with or without anti-HER2 therapy, based on the results of their pathology, showing no more cancer cells in the lymph nodes. But for people who have upfront lymph node involvement, who go through all that treatment and have residual disease in lymph nodes and et cetera, they still could benefit significantly from radiation after mastectomy, post mastectomy radiation to the chest wall and lymph nodes.
Jamie DePolo: Dr. Weiss, thank you so much. This is so helpful.
Dr. Marisa Weiss: You’re welcome. Thanks for having me.
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