Social Determinants of Health at the Global Level

In this episode, guest host, Dr. Surendra Shastri is joined by Dr. Timothy Rebbeck to discuss social determinants of health at the global level and the impact on cancer care, prevention, and control.

Dr. Surendra Shastri is a Professor, Department of Health Disparities Research at MD Anderson Cancer Center. Dr. Timothy Rebbeck is the Vincent L. Gregory Professor of Cancer Prevention at the Harvard T.H. Chan School of Public Health and Professor of Medical Oncology at Dana-Farber Cancer Institute. Professor Rebbeck also serves as the director for the Zhu Family Center for Global Cancer Prevention Harvard TH Chan School of Public Health and the Center for Cancer Equity and Engagement at Dana Farber Harvard Cancer Center. 

TRANSCRIPT 

The guest on this podcast episode has no disclosures to declare.

Dr. Surendranath Shastri: Hello everyone. Welcome to ASCO's Social Determinants of Health in Cancer Care podcast. My name is Surendranath Shastri and I serve as Professor in the Department of Health Disparities Research, the Division of Cancer Prevention and Population Sciences at the MD Anderson Cancer Center. Joining us today is the very renowned Dr. Timothy Rebbeck, who serves as a Professor at the Dana-Farber Cancer Institute and Harvard T.H. Chan School of Public Health. In this episode, we will discuss social determinants of health with a global perspective and what impact those have on cancer care in general with a little specific attention to cancer prevention and control. 

Thank you, Professor Rebbeck, for agreeing to be a part of our podcast. 

Dr. Timothy Rebbeck: Happy to join you today. 

Dr. Surendranath Shastri: Thank you very much. We are really blessed to have you on this podcast. So let's get the podcast rolling. We would like to begin the conversation with a simple question: How do you define social determinants of health in cancer care, particularly those in prevention?

Dr. Timothy Rebbeck: So I think the definitions that we need to be thinking about are really very specific to the questions we're trying to address. So there are many ways one could define social determinants. They are generally, in the United States at least, consequences of the legacy of historical, political, economic, and social influences, particularly for minority populations; those of the legacy of slavery and other related discrimination and segregation activities that have happened over many, many years and centuries, really. So that's not really an answer to how we define it, but I think that way we define it in terms of the research question or the clinical or public health question, and that using those variables that we define, we should be able to identify different groups who have specific needs or for whom we need to create interventions or prioritize activities to eliminate disparities. 

Dr. Surendranath Shastri: So speaking about social determinants of health in cancer care, particularly in the US, looking at the global perspective, I'm sure you'll agree that the social determinants might not be the same for people living in the US as compared to, say, people living in countries in South America or people living in Asia. So let me ask you a direct question pertaining to your work because you have been working globally and you have a lot of multicentric studies: Have you seen real life differences in social determinants of health based on geography and country in some of your multicentric studies? For example, you have this very large score study where you're looking at population groups of different backgrounds. So something like that? 

Dr. Timothy Rebbeck: Yes, absolutely. I would say that the categories or domains of social determinants are not fundamentally different in different parts of the world. They all involve things like access to care, insurance and payment, education and knowledge, things like that. Those are common to anywhere in the world. But the manifestation of those social determinants is really quite different in different parts of the world. So we can assume that a lot of the same factors are acting, but they are magnified in places that are low resource because the health systems and the governmental payer and care systems are quite different. The specific activities or limitations, barriers, vary by country or system. And so I think that we can think about the same problems as being universal worldwide, but the manifestation and specific things that we need to address in a particular region or country will vary quite a bit. 

Dr. Surendranath Shastri: Understood. So you would also agree that even within the same country, you will find huge disparities between populations and between people of different social classes if I'm permitted to say that?

Dr. Timothy Rebbeck: Yeah, absolutely. And so, not unlike what we see in the United States, there are people that can afford access to the very best health care in the entire world. In Africa, for example, where I do a lot of my work, the very wealthiest people can get on an airplane and fly to France or England and get their care there. And the poorest in the United States or in Africa or South America have significant barriers to obtaining the best care. And in fact, in places like Africa low resource countries, the care is, maybe for the lowest socioeconomic groups, the lowest income groups in those countries, the barriers are really substantial and probably lead to the incredibly late diagnoses, high mortality rates that you see in a lot of low and middle income countries. 

Dr. Surendranath Shastri: Absolutely. I completely agree with you because even in my personal experience, there are a couple of countries in sub-Saharan Africa which have maybe just one or two pathologists and just general pathologists - they're not even cancer pathologists.  So, it's tough for them to access good quality health care. 

So I have read some of your work, and you speak about neighborhood, social and natural environment. Could you explain that a little bit? 

Dr. Timothy Rebbeck: Yeah, I think that when we think about environmental as an exposure, there are a lot of different classes of what environment could mean. And again, it depends a lot on the question, the goal that we have in defining these different characteristics and what we want to do to ameliorate disparities. So most environment that we tend to think about is individual level exposures. So radon exposures or cigarette smoking or sunlight, whatever those may be, we think about individual level exposures. And those are, of course, incredibly important.  

But I think that there are other levels of exposure that we might want to explore. One of those is the neighborhood and contextual environments that are all around us. So where we live has an impact on our health, and particularly in the context of disparities, the neighborhood in which you live may determine your access to care. It may determine your access to healthy food. It may determine exposure to pollution, all kinds of levels that we may or may not be able to measure in a person, but we can measure in a neighborhood or an area context. Thinking about those gives us an additional layer of information about the kinds of risks people face as a group or as a neighborhood. And very importantly, they allow us to think about policy solutions. So if we can identify types of areas, say very polluted areas or areas that have very poor access to health care, those areas can be identified as having a particular need, and that need might be able to be addressed by policy or funding or things like that.

And again, I would say that's true in the United States, but it also is true in Africa or India or South America or any place where neighborhood exposures and neighborhood level factors vary, which they do everywhere. So we can learn from that, and particularly we can learn to make policy decisions.

Dr. Surendranath Shastri: Absolutely. We have large slums in many parts of Africa, as well as Asia. In India and South Asia particularly, you have large slums. You have large slums in Indonesia. So all those neighborhoods in the US—of course, you just mentioned, and the red line districts were historically denied all possible care and facilities - those districts also will be having all these problems. One example that immediately comes to my mind in the US is the smoking rates are very high among the African American Black people. Neighborhoods where you have a majority of African American Black people living, the second hand smoke exposure rates are going to be really very high. Is that what you meant by saying neighborhood social?

Dr. Timothy Rebbeck: Yes. So that's part of it. I mean, I think that individual level smoking exposures may affect the individual and may affect people in their household, but there are larger level factors that are acting. So, for example, tobacco companies target neighborhoods based on who lives there. It's not uncommon for a tobacco company to have offers for cigarettes, coupons, and vouchers that will be used in neighborhood stores in low resource neighborhoods. They will target their advertising. 

For example, we know that African Americans tend to smoke menthol cigarettes more than other kinds of cigarettes, and that's really been a consequence of advertising and targeted marketing by tobacco companies to specific groups of people in specific neighborhoods. So there's all sorts of different levels at which neighborhoods are disadvantaged because of the socioeconomic position they're in, of historic segregation, redlinings, other social determinants, and also the targeting by companies or businesses around specific neighborhoods as well. So there's a lot of levels at which these impacts are occurring.

Dr. Surendranath Shastri: Excellent examples, and I've personally seen all of those, so I know exactly what you're talking about. 

So another interesting area where you're working which could be a game changer, which may not be a game changer, we don't know really at this point of time—you might have guessed that I'm talking about MCED—the multi cancer early detection tests. So while they are being tested in countries that have the resources to do that and they will probably be rolled out in those countries, do you think, or do you perceive any challenges toward making MCED affordable, available, and accessible globally?

Dr. Timothy Rebbeck: Yeah, absolutely. So I think one of the key features of most screening tests, most early detection tests, and really clinical treatments as well, is that these new technologies usually are accompanied by subsequent disparities. So we know that any new technology is usually rolled out for the benefit of people that have access, that can afford it, that have insurance, whatever it may be. And that's true in the United States and it's also true globally. So that's an economic thing to some degree and it's a sociopolitical thing to some degree. We know this from mammography, we know this from low dose CT screening, we know it from colonoscopy that some groups benefit and others don't. And these disparities in the application of these screening tools lead to disparities in disease and outcome.  

So there's no reason to think that that MCED tests are going to be any different because it's a new technology. What we hope is going to happen is that the MCED tests will be developed in a way using diverse data—developing tests so that they are applicable to a broad scope of the population, and then implemented in a way that everyone can benefit. We hope that that will be the case. And I think that people are much more aware now of the potential for disparities to exist or be created with the development of new technologies, so that people will be a little more aware than they may have been in the past about these issues. But it's still an economic issue. The current test that's available costs over $900 and it's not covered by insurance. The tests are still being developed and we hope that that will all change so that the tests can be used and benefit everyone in low resource settings as well as high resource settings in the United States. A lot of challenges in that implementation though.

Dr. Surendranath Shastri: I really hope that happens so that avenues can be opened up for people. A lot of people who come with advanced cancers just because simple, accessible, and affordable screening tests are not available in those places. 

Dr. Timothy Rebbeck: The opportunity for low resource settings in global health for MCED tests is incredible. Because you can imagine it will always be difficult to have sufficient mammography, colonoscopy. But as an adjunct test or a low impact screening test, blood test, there's really a huge opportunity in the LMICs to create an opportunity for screening to be more widely accessible and available. But somebody's going to have to be thinking about that, valuing that, and making it economically feasible to do. And that's a big challenge. But it is also a huge opportunity.

Dr. Surendranath Shastri: Absolutely. And I'm sure a lot of your work is going to go into making those things possible. 

So this is not a trick question really, but just to know your opinion on this - do you believe on a global scale or locally politics have an impact on health care? 

Dr. Timothy Rebbeck: Politics do, but also policy does and the two go together, of course. But we know very well that if policymakers are informed by good data, informed by evidence that can guide their decisions, then they can make good decisions, they can allocate resources, they can do things that will improve health. So again, first of all, that requires evidence, it requires data. So research needs to be done that's relevant to these places. 

So policymakers also need to be convinced of how to make these investments well. There's a lot of competing needs, particularly in low resource settings, middle income countries. The resource needs are substantial and they have a lot of different burdens. So we really need to make a clear argument about why things like MCED tests or screening for cancer or therapy for cancer are a good investment relative to all the other things. And so that's an evidence based problem. But it's something that policymakers can absolutely have an impact on.

When you talk about politics, of course, that's a little bit different because politics also go beyond evidence. They go into people's values, what they care about, what they don't care about. And all of those things absolutely do matter. And we know from very many historical examples in the United States and everywhere else that politics will affect people's health. I think that politics and policy are things that will have a huge impact on our ability to improve health, eliminate disparities, things like that.

Dr. Surendranath Shastri: Absolutely. These are things which will just go on and on. And I don't see any straightforward cure for politics affecting health care. Simple example would be we don't have Medicare expansion in all the states in the United States itself. So things like that happen all across the globe, so, you know, that's really a tough thing, but we have no solutions for that. We have to just keep working on policy. 

Dr. Timothy Rebbeck: As investigators, researchers and academics, we actually can influence it by creating knowledge that people can use and then translating that into messaging and messages that politicians or policymakers or whatever can work with. So we do have a role we can play, maybe not as politicians, but we certainly have a role. And without the evidence, without the data, very few good decisions are made anyway.

Dr. Surendranath Shastri: Absolutely. I mean, healthcare advocacy is something which all healthcare professionals should get into because they're the people who really matter in terms of, of course, politics would come into play, but then policy is something which we need to guide and lead. Do you have any final thoughts you'd like to share with our listeners today? 

Dr. Timothy Rebbeck: Well, I think that the problems that face us in terms of cancer, particularly in early detection, screening, therapy, monitoring, they're really substantial problems. They're big problems, they're not things that are easily solved. But I think that through research, through policy, through influencing those people who write checks for these things, both in the United States and elsewhere, we actually have a lot of promise to make something big happen. We have seen in the United States that cancer rates have dropped and that's because of research, because of policy, because of decisions and funding that people have come up with, the National Cancer Act, there are a lot of things that have led to where we are now. And so I think it's very promising that we can do more. 

Not to say that we're anywhere close to where we want to be, but we also have opportunities in low and middle income countries to do the same. And in many places, the cancer rates are going to double or more. In Africa, we expect the cancer death rates to more than double in the coming 20 years. So now's the time we really need to be thinking about what we can do to head off that growing and predictable epidemic of cancer deaths. So we have evidence, we have people that will do it. We just need to come together and make it happen and build the evidence and convince people to invest. So I think there's a lot of promise in the future, but now's the time. We don't want to wait until cancer is the leading killer in Africa to start acting.  

Dr. Surendranath Shastri: Very well said. Professor Rebbeck. Thank you again for joining us on this episode of ASCO's Social Determinants of Health in Cancer Care podcast.  

Dr. Timothy Rebbeck: Thank you for having me. 

Dr. Surendranath Shastri: And thanks to all our listeners for being a part of this very important conversation. To keep up with the latest from Social Determinants of Health and Cancer Care podcasts, please click subscribe so you never miss an episode and let us know what you think about the series by leaving a review. Visit asco.org/equity for the latest resources, research and more on equity, diversity and inclusion in oncology. Thank you very much.  

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