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Zach Klaassen: Hi, my name is Dr. Zach Klaassen. I'm a Urological Oncologist at the Georgia Cancer Center in Augusta, Georgia, and I'm pleased to be joined today for this UroToday discussion with Dr. Alexander Cole, who's an Assistant Professor of Surgery at Harvard Medical School and Brigham and Women's Hospital. Alex, thanks so much for joining us today.

Alexander Cole: Thank you so much for having me, Zach. I'm really excited to talk about this.

Zach Klaassen: We're going to be discussing a really cool, kind of epidemiological study, looking at the intersection of climate change and potentially the impact on cancer screening. So, based on that fascinating title, what's the genesis to discuss this, and what was the reason you guys looked at this in your practice?

Alexander Cole: Yeah, so the health impacts of climate change are becoming more and more obvious. Greenhouse gas levels are at an all-time high, there's increasing evidence that climate change and global warming are irreversible, and there are certainly obvious impacts on human health in a lot of different areas. Heat strokes, traumatic injuries from landslides, hurricanes, changing patterns of zoonoses. WHO estimates there's going to be about 250,000 additional deaths every year as a result of climate change. There's predicted to be a 70% increase in heat-related deaths in the elderly, food insecurity, migration, so there are all these big changes happening around the world and they all have impacts on human health.

Clinically and research-wise, my focus is on cancer, mostly on prostate cancer. The impacts of climate change on cancer are a little bit less obvious, but they're definitely there, and they're becoming increasingly recognized. Just to point out some examples, the NCI, National Cancer Institute, created a working group on cancer and climate change last year. Just about a month ago, ASCO, American Society of Clinical Oncology, came out with a white paper, a position paper, on climate change and cancer. So there is a growing recognition, I think, that climate change is going to have an impact on cancer care and on cancer outcomes.

There are a few different areas where I think this might play out, and these are out there in the literature, I didn't come up with these ideas on my own. One of the big ones is disruptions to the healthcare system. Cancer care is really complex, requires screening, diagnosis, multidisciplinary care. You have to go to your radiation treatments, you have to go get your chemo infusions, and that type of complex multidisciplinary care is really impacted by extreme weather, for example. Population displacements, there was a nice study that came out of a group at the American Cancer Society and Mass General looking at lung cancer. When you start your treatments for lung cancer, starting radiation treatments, if you start it during a hurricane, you have a 30% higher hazard of mortality.

Zach Klaassen: Wow.

Alexander Cole: Just if you start your lung cancer treatments during a hurricane, so disruptions to the healthcare system. There are like cancer risk factors too, that's a big part of this. Increased sun exposure, when you have flooding, you have inundation of floodplains with heavy metals, carcinogenic chemicals. These are important cancer risk factors.

And then there are behavioral changes that have important implications for both cancer and climate change, and the biggest one of those is animal-heavy diets. I've done some nice work with Stacey Loeb in this area, so meat-heavy diets are one of the major cancer risk factors, and agriculture is a major producer of greenhouse gases. There are these shared risk factors. When you see all these things, the question is then how do we as cancer researchers, how do we as clinicians, if we want to try to lead health systems, how do we address these things?

The first step to that, I would say, is trying to gauge, do people understand this connection? Is there a population-level awareness of the risk of climate change and cancer, and how do these two things fit together? What I often come back to in this is lung cancer and smoking.

Zach Klaassen: Right.

Alexander Cole: I think this is a great example. In the 1950s, there were cigarette ads with doctors in them, and then over the past several decades, people realized, these things are really connected, and that went hand in hand with some major behavioral changes. When I was a kid, you could buy cigarettes at a vending machine, and you went to a restaurant and there was cigarette smoke everywhere. But that has completely changed, and people totally understand the health risks of smoking. I think that same thing will potentially happen with planetary health and with climate change. And again, the first step for this is assessing awareness of that, and that's really where this paper came out of, what is the awareness of people out there in the world when you ask them about health and you ask them about climate change, how do people understand that? And how might that be linked with knowledge and attitudes about cancer?

Zach Klaassen: Yep. No, that's a great introduction. So, let's dig into your paper. This was recently published in JNCI, so congratulations on that.

Alexander Cole: Thank you.

Zach Klaassen: What was the objective of this specific study, what you guys designed?

Alexander Cole: Yeah, so the objective of this study was really to test whether the idea of climate change and its health impacts, whether that was linked to attitudes and beliefs about cancer risk. We wanted to see whether the individuals that were aware of the health impacts of climate change also were the same sorts of individuals who were, say, interested in cancer screening, which is what we specifically looked at in this.

Zach Klaassen: So when you look at this question, and I love a good epidemiological study, it's all about finding the right database to look at this question with. So, tell us a little bit about the study design, and specifically lay out the HINTS database that you guys used for this study.

Alexander Cole: Yeah, so this is HINTS, as you said, which is an acronym for Health Information National Trends Survey. And this is a survey that is performed by the NCI, by the National Cancer Institute. The way it is administered is that it's given by post, by mail, so surveys are mailed to people, there's a cash incentive, and then there's a pretty rigorous follow-up program that they do. So if you don't reply, they call you and they follow up, and they're able to achieve a reasonably good response rate to this national survey.

The survey focuses on health communication, it focuses on health information, and it focuses on cancer information and health information, and how these two things fit together. So it's really the perfect type of survey if you want to understand people's information that they have about certain health risks and the relationship to cancer, how people communicate about cancer. And this is a study about cancer awareness and about climate change awareness, so that's really a perfect database for us to use to try to get at what's the association between cancer risk and climate change risk, and how does the information about these two things fit together in people's minds.

Zach Klaassen: That's great. So tell us about the key results, and maybe how many survey respondents there were, and just walk us through what you guys found.

Alexander Cole: Yeah, so this is a national survey, it's survey-weighted to match out the entire US population. The first things that I would like to highlight in terms of the study results are some of the descriptive data. Basically, when you ask people, "How much do you think climate change will harm your health?", it's about a quarter of people saying that climate change will harm your health not at all, a quarter of people saying it'll harm your health a little bit, about a quarter of people saying some, and about a quarter of people saying a lot. There's a nice distribution of people that have different levels of attitudes about the amount that climate change is going to harm their health.

We can say some general things about who thinks that climate change will have a bigger effect on their health. On average, women are a little bit more likely to think that climate change will have a large impact on their health. On average, younger people are going to be a little bit more likely to say that climate change is going to have a large impact on their health. Those with slightly higher levels of education are more likely to say that climate change is going to have a large impact on their health.

Then, getting into the main outcome, which is belief in cancer screening. So this was done with an adjusted model, and the outcome was interest in having a cancer screening test, and the predictor was how much do you think climate change will harm your health? We were looking at the association between these two things. Many of those other things that I mentioned, like age and education, there are some other things I didn't mention, like employment status, marital status, so these things are associated with the outcome. We wanted to do an adjusted model here to try to get the association between these specific attitudes. Obviously, you can't adjust everything, but we did do an adjusted model to try to address some of those concerns. Oh, maybe it's just the educated people who will want to do cancer screening, maybe women are more interested in cancer screening. We adjusted for those variables.

When we did the adjusted model, we found not only was, and I think this is an important point, not only was the likelihood of endorsing interest in cancer screening higher with people that had a greater interest or greater belief in the impacts of climate change, there was what I would call a dose-dependent response. As the belief in the severity of climate change increased from not at all to a little, to some, we saw an increase in the interest in cancer screening. So, 24% higher for a little, 73% higher for some, 84% higher for a lot. When you do these types of epidemiologic research, you want to see as one variable goes up, the other goes up, kind of in a stepwise fashion, that strengthens the inference, I guess you could say, that these two attitudes and these two sets of belief are related. And we definitely saw that.

Zach Klaassen: And this is based on adjusting for education and employment and all these things, right? So it'd be easy to say, let's say we have four doctors in the room or four PhDs, they're clearly aware of what's going on around them in the environment, they're obviously health conscious. But even when you adjust for these factors, that association kept getting stronger, correct?

Alexander Cole: Yeah, and obviously one thing that often comes up is we can only adjust for variables that are captured within the study. We adjusted for age, we adjusted for sex, race, employment status, marital status, education, income, where you live, whether you're a smoker. We adjusted for those things, and you can't adjust for something that isn't measured, and the word for that is an unmeasured confounder. With this type of retrospective study, you can always have an unmeasured confounder, you can have something in there that might be underlying both of these two things, and that's certainly a limitation of a retrospective study like this. But we definitely tried to adjust for all those variables that we saw in the univariate analysis to be associated with our predictor variable.

Zach Klaassen: So, the fun with these studies is always, it's hypothesis-generating, it's association, not causation, but what in your opinion is some of the implications of, say, aligning awareness of climate change and engaging in preventative health measures such as cancer screening?

Alexander Cole: Yeah, I mean, that's such an important question. We've started a research initiative in our lab up here in Boston. We're calling it ASPHIRE, which stands for Advancing Sustainability Planetary Health Impacts through Research Excellence. And we're using a really multi-pronged approach to try to address planetary health and sustainability with all the research that we do. So that's ASPHIRE.

There are three main prongs that we're focusing on right now. The first one of those is trying to provide research that will help prepare the health system for climate change. So an example of that type of research is identifying high-risk hospitals, high-risk health systems, and providing information. What is the frequency of severe climate events? What are hospitals that are critical access hospitals in rural areas? Trying to provide information that then health systems and policymakers can use to say, "Okay, these are our high-risk areas. We need to come up with some climate mitigation plan." Which, by the way, you're supposed to do, through the CDC, they want all hospitals to have climate mitigation plans. So that's one aim.

And the second aim is figuring out strategies to reduce, I would say, reduce the carbon footprint of healthcare. And this is an interesting one for me, and what I think is neat about this is that there are examples of steps that physicians can take to reduce the climate impact of healthcare that are probably things we already kind of want to do.

Zach Klaassen: Right.

Alexander Cole: One really good example of that, and we have a study looking at this now, is telehealth. So telehealth, I love telehealth. I have patients for a ten-minute return visit, they live up in northern Maine, that's a three-hour drive down, a three-hour drive back. So that's transportation and healthcare, two of the largest carbon producers in the country, right? Healthcare and transportation. We can just eliminate that by doing telehealth. And the thing that I like about this kind of a change is it's things that doctors already want to do anyway.

Another big one is just reducing waste, reducing inefficiencies, trying to streamline processes so you're not duplicating care, repeating MRIs. These are things that we're already trying to do in all of our national organizations. We're trying to improve quality, improve care coordination. And all of these things have a potential climate impact, a potential carbon impact, and we're trying to quantify that to provide ammo for us, as physicians, to then go in and say, "Okay, we should fund telehealth because look at how green it can help us be." Or "How do we change our operating room turnovers to have less waste? And by the way, just look, the doctor is home sooner." So they're have your cake and eat it too. So that's the second thing.

And then the third aim is really where this paper comes in, which is trying to link awareness of cancer risk with climate change. And I just keep coming back to smoking. I think with smoking, there was some really exceptional public health messaging that happened over the past decades to get this on people's radar that smoking is a health risk, smoking is a major cancer risk, and it's so obvious to people now that smoking is a huge cancer risk, it's a huge health risk. And I don't believe that climate change, it's not that obvious.

Zach Klaassen: Sure.

Alexander Cole: As I said in the very beginning, only about a quarter of people thought that climate change has a large impact on their health. What this paper does is, okay, here's a high-risk population, they are people that don't understand cancer risk, they're not interested in cancer screening, they don't understand the potential health impacts of climate change, and these are some targets if we want to build up this health messaging, health awareness campaign. We've done such great work with cancer awareness, and early detection, and smoking cessation, but I think one of the next frontiers is going to be climate change.

Zach Klaassen: That's great. It's a great discussion, and just to wrap it all up, anything we haven't hit on or any take-home messages that you have for our listeners?

Alexander Cole: Yeah, I think that summary covered most of it. The fact is this change is coming, whether we want it or not. I think, I believe, and I think the data would support this, that there are ways that we can make healthy, climate-positive changes, that we can use our research to find with these changes, and do changes that doctors are going to want to do.

Zach Klaassen: Right.

Alexander Cole: And then, doing things like this, having this conversation, publishing this work, can help us really get awareness, get the awareness out there, so people understand how these two things are linked and change their behaviors to address that.

Zach Klaassen: Fantastic. Dr. Cole, congratulations again on the paper, and thanks for your time today and your expertise in this discussion.

Alexander Cole: Thank you very much. I really appreciate the chance to talk about this subject. I think it's super important and I'm really pleased that we were able to talk about it today.

Zach Klaassen: Awesome. Thanks so much.