October 2014 Research Highlights

Jamie DePolo: Hello, everyone. Welcome to the latest Breastcancer.org podcast. We're doing a Research News-focused podcast today, and our guest is, as always, Dr. Brian Wojciechowski, who is the Breastcancer.org medical adviser. Dr. Wojciechowski, hello, welcome, and how are you today?

Dr. Brian Wojciechowski: Doing very well. How are you, Jamie?

Jamie DePolo: I'm great. So, we have four studies we're going to talk about today. The first one came out just a few days ago. It was a study looking at the long-term benefits of Herceptin for early-stage, HER2-positive disease. Dr. Brian, this wasn't really surprising, but it's very positive and it's good to know that this sort of standard of care has these long-lasting benefits, correct?

Dr. Brian Wojciechowski: That is exactly right. We have known about the survival benefit of HER2-targeted therapies, specifically Herceptin, in early-stage disease for quite a while. It does take a while when you're treating early-stage disease to see a benefit and see a difference as opposed to when you're treating stage IV in these studies. It's very nice and reassuring to know the benefit of adding Herceptin goes out to beyond 5 years to 10 years. This is a good thing, it means we're saving women's lives and that benefit goes out at least 10 years.

Jamie DePolo: One other thing to point out, I know sometimes it's concerning: we do know that Herceptin can cause heart problems in certain women, especially women that have preexisting conditions such as high blood pressure or diabetes. This study seemed to show that the heart problems didn't show up that much more in the group that got Herceptin, and when the women stopped getting Herceptin most of the heart problems seemed to resolve.

Dr. Brian Wojciechowski: Right. The difference was, on the one arm there was 0.2% deaths from heart problems versus 0.1% deaths from heart problems in women who got chemotherapy alone and did not get Herceptin. The first thing to say about that is that it's a very low percentage, a low rate of events. The second thing to say about it is that there's really not much of a difference between the two.

Jamie DePolo: Yeah. Very, very small.

Dr. Brian Wojciechowski: That tells me that the contribution of Herceptin to the heart problems in these patients was minimal at best.

Jamie DePolo: That's very good. That's great, and it's good to know that we have this treatment now. I guess it's fair to say for all stages of HER2-positive disease, because now we know Herceptin helps treat early stage and helps treat later stage and metastatic.

Dr. Brian Wojciechowski: Truly.

Jamie DePolo: Okay. That's a good, positive story. Our next study was looking at women who were having their ovaries removed preventively because they knew or suspected that they had an abnormal BRCA1 gene or an abnormal BRCA2 gene. When the surgeons were removing the ovaries they also found what are called occult cancers in 2% of the women. So I'm going to ask you, Dr. Brian, if you could explain to us what an occult cancer is and what this study kind of means in the bigger picture?

Dr. Brian Wojciechowski: An occult cancer is a cancer that is not apparent clinically. Consider a woman who comes in with no symptoms, lab work is good, really no indication that anything's wrong. We're doing the risk-reduction surgery, taking the ovaries out because of the high risk of cancer, and what do you know, we actually find cancer in the ovaries that we remove. That's what an occult cancer is.

Jamie DePolo: Okay. So something that was there but it was found not because you were looking for cancer, it was found doing something else.

Dr. Brian Wojciechowski: Yeah. You're doing it as a preventive thing, really. The fact that you have a 2% risk of finding an occult cancer after the surgery just confirms and reaffirms the whole idea of doing preventive surgery, that the reason we do it is to prevent getting cancer.

Jamie DePolo: Okay. So, I guess what this study is showing us then, that there really is a good reason for certain women, if they believe it's the right thing for them, that preventive surgery can really help lower the risk of being diagnosed.

Dr. Brian Wojciechowski: I think we already knew that, but this study just kind of bolsters that knowledge.

Jamie DePolo: Okay. That sounds good. That's another very good, positive study. I like these. We have another study that is going to go live on our site very soon. We're sort of giving you a preview of it now. This research was looking at the genetics of Latina women, because overall Latina women have a somewhat lower risk of breast cancer when you compare them to white women and Black women. Researchers have always wondered why that is. Are there risk factors? Are there certain things that Latina women do? Is it a genetic thing? These researchers found that there is some sort of genetic variant that seems to offer some protection to some Latina women. Dr. Brian, I don't know if we want to go into all of the science behind it, but basically it's a very common type of genetic variation, correct?

Dr. Brian Wojciechowski: That's exactly right. If you think of DNA as your genetic code, and the code consists of, say, billions of single letters, an SNP, which is called a single nucleotide polymorphism, is a very common error in that genetic code, and it consists of a single letter being replaced by the wrong letter. We all have many of these in our genetic code, and most of them really don't mean anything because most of the genetic code is actually non-coding, but these mutations, if you want to call them that, are commonly inherited in families and certain ethnic groups. That explains why Hispanic women will have them more often than, say, Caucasian or Black women.

Jamie DePolo: Okay. Yeah, and I noticed in the study they said that women who had indigenous heritage -- so they were looking at women from Mexico and Costa Rica, I believe -- so women who had heritage of the native peoples of those countries seem to be more likely to have this genetic variant. Which sort of goes along with what you said, that it's inherited in families, so it would make sense that it kind of got passed down from generation to generation.

Dr. Brian Wojciechowski: Yeah it just means that historically the indigenous peoples were more likely to mate with each other than, say, other ethnic groups.

Jamie DePolo: Okay. What this means in the bigger picture, I mean it's interesting, but what we want to say is that it doesn't mean you get a free pass if you have this genetic variant. It does help reduce risk but certainly everybody should still do everything that they can to lower their risk of breast cancer.

Dr. Brian Wojciechowski: That's right. It doesn't mean that you don't get mammograms, or breast exams, or try to limit your alcohol intake, or keep at a healthy weight. So it shouldn't give anyone a false sense of security. I think all the standard recommendations and guidelines still apply to Hispanic women and indigenous women.

Jamie DePolo: Okay. What we don't know either is if somebody did have this particular variation but, say, they smoked and drank a lot of alcohol, we don't know the effect on that genetic variant. Nobody's done that research. It certainly doesn't mean that it negates any sort of higher risk factors that you might have.

Dr. Brian Wojciechowski: Exactly.

Jamie DePolo: Okay. The last study we're going to talk about, there is a relatively new test on the market called the Prosigna Breast Cancer Prognostic Gene Signature Assay, which is a giant mouthful of words. Basically, this is a genomic test, and it was approved by the FDA. But we actually can't use it yet to make treatment decisions, we can use it to get some more information, and Dr. Brian, I'm going to have you explain why this is because the test was not tested prospectively.

Dr. Brian Wojciechowski: Right. This test is a very sophisticated, very expensive test looking at genetic changes, or mutations, in a woman's breast cancer that can help give prognostic information and separate women into different groups in terms of what is their risk for a breast cancer recurrence in the future. I think every oncology doctor, particularly breast cancer specialists, agree that these types of tests are the wave of the future. Some of it is not quite ready for prime time because we don't quite have strong enough clinical data to support their use. For example, this study looked retrospectively at patients who had already had recurrences. While that's important and while that suggests that the test could be useful in the future, it's not good enough for me to do the test on a woman and therefore say, “Oh, since you have a low risk, you can only take 5 years of tamoxifen as opposed to 10 years.” We just don't have that data yet. If you start at the beginning of a study and use the test to put women into different risk groups, and then treat some of those women with 5 and some of those with 10 years of tamoxifen and you show a difference, then yes, you could absolutely use that to make treatment decisions. But the fact of the matter is we do not have yet that strong data that we can actually use it in that way clinically. The best studies so far for tamoxifen in early-stage breast cancer are the ATLAS and ADAM trials, which showed a benefit for 10 years of tamoxifen over 5 years, and that benefit applied to all comers. So I think in the future we will be using these kinds of tests, but for me personally in my practice, I'm not convinced we have strong enough data to use it today.

Jamie DePolo: Okay. That sounds good. And just to make it clear, this Prosigna test was designed for postmenopausal women who had been diagnosed with early-stage, hormone-receptor-positive disease. They had been treated with 5 years of hormonal therapy, and the idea was the test would then help give a risk score for women who were either more likely or less likely to have a recurrence in the body away from the breast, a distant recurrence, after the 5 years of hormonal therapy. So, the idea, in theory, is that it could perhaps help doctors decide who would benefit more from taking hormonal therapy for 10 years. But as you just told us, Dr. Brian, the studies show that all women benefit from 10 years of hormonal therapy.

Dr. Brian Wojciechowski: Yes, and I think that if we had better and stronger studies we may be able to, in the future, based on using a test like Prosigna, select out certain women who only need 5 years. And I hope that's where we go eventually, but I don't think we're there yet. Let me just add on that I mentioned tamoxifen, but obviously this would also apply to women taking aromatase inhibitors such as Femara, Arimidex, and Aromasin.

Jamie DePolo: Okay. Alright, thank you very much for clarifying that. That's always good to know. So while the test results are promising, as you said, perhaps not quite ready for prime time yet. More research is probably needed before we can use these results to really make treatment decisions.

Dr. Brian Wojciechowski: Exactly.

Jamie DePolo: Alright. Thank you so much, Dr. Brian. You've been very helpful in explaining a lot of this very complicated research. As always, we appreciate you taking the time to talk to us for the Breastcancer.org Research News podcast, and we will be back with you next month. Right?

Dr. Brian Wojciechowski: Sounds good to me.

Jamie DePolo: Alright. Thank you so much.