Breast Cancer Survival Differences in Black and White Women

Jamie DePolo: Hello. As always, thank you for listening. Our guest today is Dr. Kent Hoskins. He is the Eileen Lindsay Heidrick Professor of Oncology and the associate director of translational research at the University of Illinois Cancer Center at the University of Illinois Chicago. One of the aims of his research is to reduce the number of people who die from breast cancer by better identifying people who are at high risk of the disease.

He is also keenly interested in disparities in breast cancer survival rates between Black and white women. He joins us today to talk about his latest publication in JAMA Oncology, a paper that found that both the biology of a breast cancer tumor, as well as the environment in which women live, contribute equally to this difference in breast cancer survival rates. Dr. Hoskins, welcome to the podcast. Thank you for joining us to talk about this extremely important topic.

Dr. Kent Hoskins: Thank you, Jamie. It's a pleasure to be here.

Jamie DePolo: So, before we get into the actual specifics of your research, could you give us some background and a little overview on this survival difference between Black and white women with breast cancer?

Dr. Kent Hoskins: Sure. And there's really two ways one can think about racial differences in breast cancer death. Versus from a population standpoint when we talk about mortality rate. So, what are the number of deaths per 100,000 women in the population? And really, before the late 1980s, there was no mortality difference. There was no disparity when you looked at the number of deaths per 100,000 population in Black and white women in this country.

And then what you see in the late 1980s, suddenly, those curves start to separate due to the number of deaths. And of course...and it's been 40 some years now, and unfortunately, that mortality difference has stayed very constant, despite 40 years of efforts to try to understand and really mitigate that. The obvious question, of course, that leads to, is what happened in the late 1980s? Why did this suddenly emerge at that time point when there was no difference prior to that?

And really, two major things happened right around the same time that we believe are really drivers of that change. The first is screening. That's really when mammographic screening became widespread and standard of practice, standard of care, for women as part of routine healthcare. Well, right about that time, several large mammographic screening trials were mature, showing data that reduced mortality, and so, that became a standard of care.

Second thing was treatment change. That's really when we start using medicine to treat early breast cancer to prevent it from returning later. And so, those two major medical advances really came online right when you see those curves start to diverge. And of course, that then really raised the question, well, why is that? And what we're seeing there really has been seen over and over again in multiple disease types. And that is that, unfortunately, disparities in health outcomes emerge in the wake of medical advances. And that's because, frankly, advances don't benefit everyone in society equally.

We live, unfortunately, in a society with great inequities, and certain groups do not benefit from advances to the same extent that other groups do. And so that's really what we're seeing. And again, you can look at multiple diseases, and you can see very clearly when there are medical advances in that disease, suddenly, either disparities emerge or they worsen, if they were there to begin with. As in the mid-1980s, look at the population level. Black women have about a 40% higher mortality rate. In other words, number of deaths per 100,000 compared to non-Hispanic, white women.

That, of course, raises two questions, then. Well, is that because there is more breast cancer happening in Black women, which, of course, could lead to more deaths? Or is it because Black women don't do as well once they develop a diagnosis of breast cancer? So, is it what we call an incidence issue with more cases? Or is it a survival difference? Meaning worse survival once it happens?

The first thing that we realized was that, back at that time in the '90s and in the early 2000s, Black women were actually less likely to develop breast cancer. So, it wasn't that they were getting more breast cancer. It was really a survival difference. Meaning once it was diagnosed, they were less likely to be cured. Now, there's been some nuance to that, and so, what we've learned over the years is that there are actually different types of breast cancer, as your listeners might know. And one particular type that's been traditionally thought of as the most aggressive type, known as triple-negative breast cancer. It turns out that actually is more common in Black women.

So, Black women are about twice as likely to develop the triple-negative type of breast cancer, compared to non-Hispanic, white women. But that's still a small fraction. That still makes up only, at most, a quarter of breast cancer cases. So, that's part of the issue, and that's been known now for, you know, over a decade, that Black women are more likely to get that aggressive subtype. But again, that clearly doesn't explain the whole picture.

The other thing that became clear very early on was that Black women were more likely to be diagnosed at more advanced stages. And we know, certainly, with breast cancer, as with most cancers, the more advanced the stage at the time of diagnosis, you know, the less the chance of curing the cancer and the greater the chance of cancer death. And certainly, that has been a very big component of that disparity. And then, as we kind of peel the onion, we say, okay, then why is that? Why are Black women more likely to get advanced-stage disease?

And really, in the earlier years of this, you know, research on this topic, the big focus was really on mammography screening. And of course, if there were lower screening rates among Black women, then it would be expected that they may have more advanced-stage disease, and indeed, that was the case back in the '80s and '90s. There's been a lot of work done to try to narrow that screening gap. For the most part, those efforts have been pretty successful.

So, in the most recent data, overall, there really are not big gaps in the rate at which Black women have mammographic screening compared to white women. There are pockets in certain areas and in very, very disadvantaged areas where you still see it, but overall, in the country, the rates are pretty similar now. But again, the more we look, the more we realize how complex this issue is, and so, there's also been research done showing that even if the rates are the same, the quality of the mammography's not always the same.

So, it's one thing...you have to, of course, get the test first, but then it has to be a high-quality study to really get the maximum benefit. So, there's been quite a bit of work done showing that there are disparities in the quality of mammography, which is going to, again, lead to more misdiagnoses in Black women in disadvantaged communities. So, that certainly plays a role, as well. So, it's really been multiple issues that are all kind of conspiring here to create this disparity.

Now, you know, of course, we haven't even talked about treatments. And as we said, overall, since the incidence is not higher in Black women, that suggests worse outcomes once they're diagnosed. We talk about part of that reason, which is, again, more likely to have advanced-stage disease, but even if you adjust for differences in stage of disease, there are very clear disparities in treatment, as well. Many, many studies have shown that over and over again.

Whether we're talking about the use of hormone therapies, which are important in breast cancer. Talking about, you know, chemotherapy, radiation. And it's not just whether people get it, but it's how timely do they get it? We know that delays in initiating treatment certainly can lead to worse outcomes, and so, that's been shown over and over again: Black women are more likely to have delays in starting treatment. And there are interruptions, and again, think about things like radiation, where you have to come every day.

Well, transportation becomes a huge issue. If someone lives in an inner city area where they have to take public transportation, they're more vulnerable to disruption. So, there's multiple levels of, really disadvantage that are all really kind of conspiring here to create this disparity. If we've learned nothing else, we've learned that it's not one thing that's at the root of this. It's multiple things. It's almost everything you can think of related to cancer, diagnosis, and treatment is contributing to some of that.

Jamie DePolo: Okay. I do want to ask one thing. When you talked about when these survival differences started appearing. I want to make sure I'm understanding you right. Is that survival difference, has that kind of stayed the same throughout these years, or has it grown? Have those curves widened, or has it pretty much stayed the same?

Dr. Kent Hoskins: So, what we see is, within any racial group, we see that the mortality rate in the population has declined as we've had better treatment. But this gap between Black and white women has stayed very stable at 42% for...as I said, it's been now, you know, for 30 or whatever years. It didn't take very long for it to go from no difference to that 40%. That happened within less than a decade, and now it's been, unfortunately...the overall rates are coming down, but there's that gap. We haven't closed the gap.

Jamie DePolo: That's interesting to me that it stayed the same over these years, especially since there's been quite a bit of research looking at it. It's kind of fascinating to me.

Dr. Kent Hoskins: Yeah. Yeah. It's fascinating. It's discouraging, but I think, you know, again, what we're realizing...and you hear the term multilevel root cause of health disparities, and that's really true. The root causes occur at multiple levels throughout...you know, in society, and so, fixing just one thing doesn't generally fix the problem. And so, it's really a matter of trying to tease apart all the different elements, painstakingly fixing one at a time or addressing it as best we can, you know, but realizing that things are operating at multiple levels.

Now, you know, I want to give some good news here, and these things can change. So, I live in Chicago. Twenty years ago, the racial mortality gap in Chicago was one of the worst in the country, and that really prompted some community organizers and some advocates to really rally around that problem and try to create community solutions, where they brought together academic institutions from across the city, advocacy organizations, to really partner and to start to not only understand it, but to start to try to institute solutions.

And that's been very effective. If you look in our city, in Chicago, that gap has gone down dramatically in the last 20 years when, nationally, it has not. So, it's not just that things are getting better everywhere, but really, differences...you know, we can make a difference, but it takes a lot of concentrated effort, and it's all rooted in the science to understand what's driving this, and then now, how do we start to systematically address those different issues?

So, in Chicago, for the first, you know, 10 years, the focus was on mammography quality and access. And that's made a big difference. Now, we haven't eliminated disparity, but it has come down. So, I think, locally, we do see improvements, but we're not yet seeing it reflected nationally, because we don't have a coordinated national strategy to address this.

Jamie DePolo: Right. Right. That makes sense. So, I want to get into the science. I want to talk about your paper, which said that it was both the biology, or the characteristics of the cancer, and what you and other scientists call social determinants of health. They equally contribute to this survival disparity. So, if you could explain for us, what are social determinants of health and how they can affect breast cancer outcomes?

Dr. Kent Hoskins: Sure. I think the simplest way to think about social determinants of health is to think of them as non-medical factors that influence health outcomes. And so, these are just, basically, the conditions in which we are born, we grow, we learn, we work, we get older, we receive healthcare. It's the conditions in which our lives exist. And so, if you think about multiple factors really influencing our health, behaviors, and our outcomes, so all the way from policy issues, how do we finance healthcare in our country?

That's a social determinant, and as we all know, there are great inequities in people's abilities to finance their own healthcare. It affects where hospitals locate, right? So, we know that highest-quality hospitals tend to gravitate towards where's the most private payers. And so, folks in economically disadvantaged areas, they're going to have less easy access to high-quality care. It affects social factors like transportation. If you live in a city that has poor public transportation and you don't have a car, that's going to affect your ability to access healthcare.

It affects our disability insurance, the way our employment system works in terms of people's ability to take time off of work to go to doctor's appointments. If you have a job, certain jobs, you have much more flexibility where you can take the morning off and go to a doctor's visit. Other jobs in our society, you don't show up, you don't get paid. So, these are all social factors. They're not medical issues, but they directly influence the ability of someone to access timely, high-quality care.

It even goes beyond that. It extends to where you can buy food. If you live in an area where there are very few healthy food option choices, that's going to limit your diet, and we know diet has a huge effect. If you live in an area where there aren’t green spaces and you have a climate like ours in Chicago, how do you exercise? How do you get physical activity in the winter if you don't have places where you can go? So, again...and I could go on and on and on.

I think you get the point. So, it's easy to think about simply the financing of insurance, but there's much, much more. It's much broader than that, and it's really at every turn where you think about your life and what is needed for you to access healthcare. There are social factors that influence that, and unfortunately, particularly in the African-American community, you have concentrated disadvantages for almost all of those factors.

Jamie DePolo: Okay. So, could you summarize your study for us, because I thought it was very interesting that you found that...I mean, it makes sense, but I had never heard anybody talk about it or write about it in this way. So that these environmental factors, or these social determinants of health, as well as the characteristics of the cancer, were both contributing equally to this disparity in outcomes.

Dr. Kent Hoskins: Sure, and so, I'll give a little bit of background. I mentioned earlier that it's been known for, you know, 15 years or more that Black women are more likely to develop the triple-negative, the aggressive subtype, and again, that's really the bulk of breast cancer disparities research, is focused on that, which is an important issue, and then it’s focused on access to care kinds of views. Also extremely important, the social aspects.

But what really had not been getting much attention was the fact that even though Black women are more likely to get the triple-negative, that still is only a quarter of breast cancer cases among Black women. They're twice as likely, but it's still only a quarter. Three-quarters of breast cancers in Black women are the so-called hormone-dependent or estrogen receptor-positive type of breast cancer.

And there've not been a lot of investigations of that particular subtype. And so, we started, about 10 years ago, asking the question, well, that's the most common, and are there differences among that subtype? And we started by looking in Chicago. We found that, lo and behold, when we now talk about survival, an individual person diagnosed with a cancer, what is their chance of being alive in five or 10 years? Which is different than the population view of death and mortality. Now, it’s okay, you've been diagnosed. What is your chance of being alive in five or 10 years?

And what we found was that among the triple-negative type, there wasn't a real big difference. Black women were more likely to get that subtype, and it was a...for everyone who had that, it was a worst outcome. But there was not a big difference in our study early on between Black and white women with that subtype.

Now, again, that's been mostly recapitulated in other studies. There've been a few studies saying that there is a difference, but certainly, there's been less of a difference. But on the other hand, when we looked at the more common hormone receptor-positive tumors, we saw a very large difference in survival, the chance of being alive five years, 10 years down the road.

Jamie DePolo: Well, see, that's very interesting. I'm sorry to interrupt. I just want to add one point and make sure I'm understanding it right, too. Because, to me, a lot of doctors have told me that hormone receptor-positive breast cancer is considered treatable. It's very treatable. There are a lot of treatments. You know, we have the aromatase inhibitors. We have tamoxifen. We have a lot of treatments for hormone receptor-positive disease, so it's very interesting that there is this disparity there.

Dr. Kent Hoskins: No, exactly. That's exactly right, and again, I think that's part of why it was not getting a lot of attention, because people view that as exactly as you said, the more favorable subtype. So, there's focus on the triple-negative, which is more unfavorable, fewer target agents, and all that. So, you're exactly right, and I think that's a big reason why there wasn't a lot of attention paid to that.

Now, that's really changed in the last few years, because there's been many states coming out now showing that the bulk of the data, I would say, showing that, relatively speaking, the proportional...the gap is bigger in hormone receptor-positive.

Now, in our study, we tried as best we could to adjust for differences in treatment, differences in stage, and when we did all those adjustments, we still saw, you know, a two- to three-fold higher risk of breast cancer death among Black women, even if you, again, try and equal out differences in stage and treatment.

Now, the big caveat there is it's very difficult, particularly the hormone receptor-positive breast cancer, to be certain that there aren't differences in treatment. Because, as you pointed out, much of the treatment is oral through pills, and they're not administered at a hospital or a doctor's office. And so, it's much harder, from a research standpoint, to be sure that there's the same use of those pills among different groups of women. And you know, we can do things like, we can get pharmacy records and insurance records and all that, and that's been looked at.

But even that, we don't really know that if someone filled the prescription, they're actually taking it. So, it's very difficult, particularly in this subtype, as you point out. The hormone receptor-positive, where the endocrine therapies are such a big part, it's been hard to be sure that that isn't what's driving the difference, differences in treatment. And so, we and others have done our best to adjust for that, but there's always that caveat that even if a person fills a prescription, you don't really know. Now, that's been looked at a great deal, and it is a little conflicting.

Some studies are showing that there's a lower rate of use of hormone therapy among Black women compared to white women, but in some of the best studies that've really carefully looked at that, even if you adjust for those differences, the disparity remains. So, while that may contribute, it's never, in any studies shown, to totally explain those differences. And so that got us thinking, well, that all suggests there may be some differences in tumor biology. So, that's really the seed for that question.

No one is questioning the importance of the social determinants in terms of, you know, more advanced stage, in terms of treatment differences. That's a given. The question is, if that doesn't explain all of this disparity, what explains the remaining part? And so, that's really where we started looking at the question of biology, which led to the study that we just published that you're referencing today. And so, for that study, we wanted, as much as we could, to eliminate as many of the other variables. So, we wanted to eliminate differences in advanced-stage disease.

So, we took women with the earliest stage disease, lymph node-negative tumors. We wanted to have the best measure of biology, because we knew there were going to be some limitations on what we could infer about treatment. But if we had a hard measure to a biology, you know, that's a good indicator. And so, there's a test that's often done that your listeners might be aware of called the Oncotype test. That's routinely used in this country now for women who have these hormone-dependent or estrogen-dependent breast cancers, to determine whether or not they'd benefit from chemotherapy. 

And so, it's a clinically-used test. It's the most commonly used, what we call, genomic test in breast cancer in this country. And we were fortunate that there's a large national registry, called the SEER registry, of all different types of cancers, including breast cancer. We'll call it population-based sampling of 18 geographic areas around the country to give us, really, a good snapshot of what's happening around the country. And the SEER registry actually was able to link to the company that does the Oncotype test to get Oncotype data on women who were in this SEER registry, and so, they created that database.

So, we were then able to take that data and then start to parse out what's the role of biology versus social determinants. The other, again, reason we were about to do that was the SEER registry collects information on neighborhood. So, they collect, on all women in the registry, the census tract that the woman lives in when they were diagnosed. They also collect information on type of insurance. So, because we know the neighborhood, we can then go to census tract data. We can get data on what is the average income in a woman's neighborhood? What is the average rate of education? What is the poverty rate?

And so, we can then create a picture of the neighborhood disadvantage that each woman resides in as a measure of kind of a global measure of these social factors. And so, by looking at both health insurance, which is more of an individual factor, and then looking at the census tract neighborhood, which is more of your environment that you're living in measure, we could really get a reasonable measure of these different social factors.

Now, I want to emphasize, by no means is that a comprehensive measure of the social forces that act on people. But with this dataset, it was the best we could do. And so, that then allowed us to then ask the question, how...and by the way, SEER also does collect treatment data, but again, as I mentioned, that's always dicey to really be sure it's accurate.

And so, that then allowed us to ask a question, through a statistical analysis, how much of the racial disparity in all these early-stage, supposedly favorable-prognosis tumors can we attribute to biology based on this Oncotype score, which is a very direct measure of the biology of the tumor, and how much of it can we explain by how the neighborhood affects that individual socioeconomic status, as noted by insurance and treatment and even tumor size.

And so, that was the background to allow us to really tease out those difference. We had done an earlier study showing that Black women were more likely to have a high-risk score on this Oncotype. So, we knew going into this particular study that, indeed, Black women do have a higher chance of a more aggressive form of hormone-dependent breast cancer, but we didn't know how big of a part that was playing relative to the social factors, and so, that's what then led us to this particular study.

Jamie DePolo: So, and the results found that they were equal. So, I guess I have a couple questions. How do we put this in context for this disparity? What does this mean?

Dr. Kent Hoskins: Sure. You know, as hopefully all good research does, it raises as many questions as it answers or more, because, you know, it takes you to the next step. And so, a couple of points to make about that. So, as you said, what we found was that when we combined what we call individual-level measure of disadvantage, which is the insurance type, and a neighborhood level of disadvantage, when we combine those, it's kind of one measure of overall disadvantage, if you will. That explained 20% of the disparity.

So, by the way, we found that Black women with the earliest form of breast cancer were 80% more likely to die compared to non-Hispanic white women. So, that was kind of the baseline disparity, 80% higher rate of death, following what's supposed to be a very favorable type of breast cancer. Now, as I said, of that difference now, we could explain 20% of that difference, so a fifth of it, basically, by the social factors. We could explain another 20% of it based on the differences in biology. About 10% was explained by differences in treatment, and Black women had a little bit larger tumor size, so that played a small role.

That means that over half of the disparity is still unexplained by everything that we could look at. So, that's one important point to note. Now, we have all kinds of hypotheses. What might be that missing contribution? And there probably are differences in treatments that we weren't able to capture. We know, and everyone knows, that that SEER database has some limitations in the detail of treatment. For example, it does not have data on, were there delays in starting? Which we know is important. Were there more interruptions in treatment? Were there more dose reductions? None of that level of detail is available in the SEER database, so that's probably part of it.

We don't have data, as we talked earlier, about hormone therapy, because, again, that's not hospital-based data. That's something, you know, in clinics and pharmacies, and that type of data is not available in SEER. So, there probably are some differences in that, but we know that our measure of biology that we use, it was the best that was available. But that's by no means a comprehensive measure of tumor biology, and we now know with some other work we're doing, that there are biological differences that are not reflected in that Oncotype score. So, there almost certainly are additional biological components that we were not able to capture. And so, again, there's still a big piece that's missing, but again, as you said, the take-home was that, from what we could measure, the biology seemed to contribute as much as the social factors.

Now, another important point is, again, that then raised the question. Well, why are there biological differences? And this can be a fraught area, so I always like to like to take pains to make sure we're really clear on this. Because, one, when you start talking about biology and race, there's very ugly history. We are certainly not saying that there are inherent differences in biology overall according to race.

What we're saying is that when a cancer develops, the biology of that cancer is influenced by lots of things, because we noticed a wide variability in how aggressive tumors can be. And something determines that. And so, one of the things we're very interested in is how do the social factors actually influence biology? They're not actually totally separate. They're probably related. Now, for the study, we separated them to try to get individual components, but in fact, there's probably some relationship, and so, we tried to get at that, as well.

We did find that living in a disadvantaged neighborhood made you more likely to have a biologically-aggressive tumor. Now, it didn't explain all of the racial difference. It was a relatively small component, but now we have hard evidence saying that these social factors not only affect the quality and the timeliness of treatment and screening and all that, but that also affects the biology of the tumor. And so it's the multi-headed monster that, you know, just keeps popping up in other places. So, these social inequities, everywhere you look, you find they have an effect.

And so, I think that's another important message here, is that what we as a society prioritize and how we decide to live our lives influences people's health in dramatic and not always obvious ways. And so, my hope is that this can also be, you know, more ammunition to really try to affect some social changes. Because, again, this is one example. There are many, many diseases where you can see the same thing, which is the social conditions that people live in influence not only their access to care, which is very important, but also the biology of the diseases that they get.

Jamie DePolo: I just want to ask you a question, more of an example, to make sure I'm understanding it. So, say somebody lives in an area. It's on the more disadvantaged side. They don't really have good access to a grocery store with fresh fruits and vegetables, and so, maybe they're shopping at a more convenience store where there's a lot of prepackaged, processed food. To me, that's an example, so, then if somebody's not eating healthy, that could potentially affect the aggressiveness of the cancer or affect how likely they are to develop cancer. Is that a good example?

Dr. Kent Hoskins: Absolutely. That's a great example.

Jamie DePolo: Okay. Okay. So, that makes a lot of sense to me. And then the other thing I'm wondering, too, I know you said you couldn't really get at the treatment for sure. But I have read studies suggesting that hormone receptor-positive cancers are more likely to come back, say, 10 years after diagnosis, as opposed to hormone receptor-negative disease or triple-negative disease, which seems to be more likely to come back in the five years after diagnosis. And I'm wondering if that's going to play into any of your future research?

Dr. Kent Hoskins: You're exactly right about that. And that's one of the questions we had to ask ourselves, and reviewers asked us that same question. It's been shown in other work that the disparity, the survival disparity, emerges very early, both in triple-negative and in hormone receptor-positive breast cancer. So, the racial disparity is there within two years. So, even though you're right, that the risk of recurrence continues out to even 20 years, because we're focusing on that difference, that emerges early.

Now, could it be that that difference, you know, goes away later? That's possible. I've never seen any data showing that. So, our response is that, yes, it would definitely be great to see are these differences any different 10 years, 20 years down the road, but we know that they emerge early, and so far as we know, the publications to date don't show those survival curves coming back together. So, we're assuming that what we're seeing now, I think we can fairly safely assume, is going to, more or less, hold with more time.

Jamie DePolo: Okay. Okay. Thank you, and I guess, so, if I'm a Black woman who's been diagnosed with breast cancer, what can I take from your research? Like, how can this help me?

Dr. Kent Hoskins: That is the question. That is the question. A couple of things. I think, number one, we recommend that all women, you know, are really advocates for their own health, of course, and certainly, we recommend that strongly for Black women with a breast cancer diagnosis. What is becoming clear is that, as we said, even though we don't have all the details, those social conditions put Black women at a disadvantage, whether it's how quickly they get their diagnosis, how quickly they get their surgery, how quickly they get chemotherapy, radiation, et cetera, and those things matter.

Those things could really add up to worse outcomes. So, my first advice is, it's unfortunate that we have to have women be their own advocates. You know, we wish we lived in a society where we didn't need that, but unfortunately, we do. So, be your own advocate, but also ask for help. And you know, friends, family, you know, people want to help.

So, if people have trouble getting transportation, you know, it's important to get to those appointments and not miss them, and it's also important that if you're getting put out, you think too long to get treatment, you have to advocate for yourself and say that that's not acceptable. And again, you know, we shouldn't have to do that, but unfortunately, that's the reality of the world that we live in. So, advocating for yourself for prompt, timely care, and if you need help with that or you need to find someplace else that can provide that, you know, self-efficacy. Take charge. And again, we're not, by any means, blaming the women, of course, by saying that. It's unfortunate that women have to be their own advocates in that way.

The biology's another question, and we don't really know what's driving all the biology. We certainly recommend, as you pointed out earlier, healthy eating. That's very important. You know, exercise, weight control, those things. But from the biology side, a lot more work needs to be done. So, I think that's the message from my standpoint.

You know, what got the headlines, I think, in this paper was, the biology was sort of elevated because people had not been paying a lot of attention to biology in hormone-dependent breast cancer. All the biology questions looked at triple-negative, and that was our main question. But I think the underlying issue still is that social factors are root causes, even, potentially, in these biology differences. And so, we have to not lose sight of that. You know, I think, you know, if you said what is the take-away if I'm an oncologist, which I am, for our healthcare system?

Again, recognizing that we have not taken the same amount of effort to try to reduce barriers for disadvantaged women that we need to. And just assuming, you know, that I set up my clinic and people show up when they need to, get it. You know, there are all kinds of things in people's lives that make that challenging, and so, if we're not proactively trying to bring down those barriers through navigation, patient navigation, which is a huge benefit because it helps overcome those barriers.

So, having active navigation programs is critical to try to eliminate some of these. You know, we can't change the way our insurance system works, probably, right away. And you know, it's going to be a long slog before we really can change the financing and you know, some of the other things. But we can do the best to sort of overcome those barriers, and patient navigation's been a huge thing when it's been implemented. And so, having healthcare systems recognize that this is driving those worse outcomes, and one of the best ways to help your system to address it, is to build programs that really support and that bring down those barriers.

Jamie DePolo: Okay, and one final question before I let you go. This has been so fascinating. One thing that occurs to me, too, is we know that Black women are less likely to be in clinical trials for new breast cancer treatments. So, while we have all these data about the efficiency of...or efficacy, I guess, is the more appropriate word, of things like tamoxifen and the aromatase inhibitors and some of the other treatments, most of the people in those studies have been white women. From your viewpoint as an oncologist, do you think that it's possible that, perhaps, these treatments are not as effective in Black women or that there could be a difference there?

Dr. Kent Hoskins: Absolutely. I'm glad you brought that up, actually. A big part of the work we're doing now is trying to address that exact issue. Absolutely. I didn't get into this, but this Oncotype test I was telling you about, which is the most commonly-used test in the United States to determine which women with these most common breast cancer types need chemotherapy.

If you look at the studies that were done to develop that test, the diversity in those populations was very, very small, 1% or 2% Black women, less than 5%. We published some other papers, and we have one that's kind of undergoing review right now looking at the accuracy of that test for Black women. And what we were finding is that it underpredicts the benefit of chemotherapy for Black women. It's not as accurate predicting long-term prognosis, and it underpredicts benefit of chemotherapy, and that's just one example, and to your point.

So, yes, treatments, absolutely. And in 2020 I believe, if you look at all the new breast cancer medications that've been approved and you look at the representation of Black women, it's less than 5% in those trials. And so, getting back to the biology question, if there are differences in biology in the tumors, which there clearly are, then it's quite probable there are differences in response to treatment. What that means, you know, what that means therapeutically, we don't know yet, of course.

Clearly, that's likely to be true. Really getting better diversity in clinical trials is imperative because effectiveness and side effects, actually, you know, can vary according to...again, if you’re disadvantaged, there may be some ancestral genetic variance, as well, that can influence effectiveness of treatments and side effects. So, I think that's a huge, huge part of the issue, and there's been increased attention on that, but unfortunately, not a lot of progress. That's the big area of work.

Jamie DePolo: Okay. Dr. Hoskins, thank you so much. This has been so interesting. I really appreciate your time, and thank you for sharing this research with us.

Dr. Kent Hoskins: My pleasure. Thank you, Jamie. It's been a fun conversation.