Expert says actions to combat climate change could prevent, improve cancer outcomes

Climate change and cancer share a root cause — our reliance on fossil fuels, according to Leticia M. Nogueira, PhD, MPH.

“We no longer need predictions or hypotheses about how the consequences of climate change affect cancer risk and outcomes. We now know they share a root cause,” Nogueira, senior principal scientist in the surveillance and health services research program at American Cancer Society, told Healio. “The same air pollution from vehicle emissions that increases greenhouse gases also increases lung cancer risk.”

Nogueira spoke with Healio about her research on climate change and cancer, why it is important to bring this information to light and the significant need for more research in this area.

Healio: How did you become involved in this work?

Nogueira: I have worked in the oncology space for most of my career, but climate change was not something that was on the radar for many in the field. The oncology specialty has lagged behind other specialties in terms of understanding the connection between climate change and health hazards.

After working on the Hurricane Harvey response in Houston in 2017, I accepted a position at the American Cancer Society and the very first project that I proposed when I joined was to examine the impact of hurricanes on patients with cancer. My experience was that I was coming fresh from dealing with the Hurricane Harvey aftermath, but nobody else was. So their response to this was laughter, and they said that climate change had nothing to do with cancer. However, when I bring up climate change and cancer now, I do still receive some puzzled looks, but not necessarily laughter anymore.

Healio: How is climate change connected with cancer?

Nogueira: There are several connections — especially interruptions in access to care. Patients with cancer are a vulnerable population, and their proximity to fossil fuel infrastructures increases exposure to carcinogens and cancer risk and outcomes.

When I worked at the Texas State Health Department, I was directing several state health registries when Hurricane Harvey hit. I experienced climate change firsthand because the hurricane was different from previous hurricanes. It wasn’t the first time Houston was impacted by a hurricane, but this one was different because it wasn’t so much the wind but the rain and water that made a significant difference. Warmer air holds more water vapor, so climate change impacts the water capacity of hurricanes. Because Hurricane Harvey was different, everything flooded and many people could not get access to medical care, including patients with cancer. From an oncology perspective, it was obvious that extreme weather events can have an impact on survival outcomes for patients with cancer because of interruptions in access to care.

Patients with cancer are also vulnerable to the health hazards of climate change. For example, patients with lung cancer who are impacted by a wildfire during recovery have worse survival. This vulnerability goes beyond exposure to the smoke and includes the stress of potentially having to evacuate as well as threats to health and property.

Moreover, some cancer therapy modalities impact thermoregulation, increasing sensitivity of patients with cancer to heatwaves or winter storms, both of which are becoming more common with climate change. Many cancer therapies additionally affect the immune system and patients may be more vulnerable to infections, which are common during flooding events.

Healio: Are certain cancer types affected more by climate change than others?

Nogueira: All cancer types can be affected by climate change because climate change impacts every step of the cancer care continuum, including prevention, screening and timely diagnosis, treatment and survivorship care.

Disruptions in access to treatment during hurricanes impact survival, and patients undergoing chemotherapy experience increased sensitivity to the health hazards of climate change.

Cancer prevention is also affected. Carcinogens released by fossil fuel infrastructure, including benzene and formaldehyde from fracking operations, are associated with increased risk for leukemia, for example. This is in addition to the most obvious link between air pollution and lung cancer.

Healio: What key research has been published on climate change and cancer?

Nogueira: There hasn’t been much research, but it is growing.

Our understanding of the vulnerability of the health care system during disasters is improving, as well as identifying the populations that are most vulnerable, such as those with certain health conditions, including cancer. Recognition is also growing that many carcinogens already identified by the International Association for Research on Cancer — the oncology arm of WHO — are released by fossil fuel extraction, processing, transportation and waste management in nearby communities.

Healio: What research is underway?

Nogueira: Climate change impacts many aspects of oncology, including prevention, access to care and survivorship. It impacts so many different types of cancer, each of which has a unique risk profile. It is easy to get overwhelmed but one way to make sense of current research efforts goes back to the fact that we have three choices with climate change — suffering, adaptation and mitigation.

With suffering, the role of research is mainly documenting how climate change is already impacting cancer. This type of research shows that individuals who are impacted by a hurricane during radiation treatment have worse survival, for example. This type of research is important because it increases awareness within the oncology profession.

The second area of research that we are working on is adaptation — basically, what can we do? I am working with other researchers and cancer centers on emergency preparedness plans that include how to identify vulnerable patient populations before a disaster strikes. For hurricanes and several other climate disasters, we have a warning period, so how can we make sure that weather alerts and emergency instructions are provided in the relevant languages, are culturally appropriate and reach the most vulnerable population? How can institutions help patients with cancer preregister for special needs shelters or evacuate safely? Also, are there patient transfer agreements in place?

It is also important to understand whether anything can be done to modify the way that we are providing care during disasters, such as consolidating appointments to minimize the time that a patient has to spend outdoors during a wildfire. In short, what are all of the different ways that we can start to address the unique needs of people who have been diagnosed with cancer in an equitable way? With this being said, we do not have to reinvent the wheel every time. We can learn from the experience of other communities that have been through something similar. We should work together and build on lessons learned elsewhere and continue to improve in this area.

The third area of research is mitigation. We must start thinking about how to solve the climate change problem. The health care system is the second most energy intensive industry in the U.S. and there are many opportunities for mitigation efforts.

However, one of our guiding principles is that we don’t want to add burden to physicians who are already boots on the ground doing the work as health care providers and fighting the good fight. This is where co-benefits start showing up. For example, switching to clean energy sources, especially those generated onsite, can decrease institutions’ emissions, and also make them more resilient to power outages that are only becoming more frequent with climate change.

Moreover, working to include climate change as a topic in medical and professional conferences to increase awareness is an important way to start the conversation about sustainability efforts at these conferences, such as offering a virtual option for attendance, reducing paper use and serving environmentally responsible food items.

Healio: Why is this information important for oncologists to understand?

Nogueira: Oncologists wake up every morning with the same goal — to decrease the cancer burden and to have a positive impact on people’s lives.

Recognizing the threat of climate change is important because if we do not recognize it, we will be blindsided by it. It is also important to be better prepared and have plans in place for when disaster strikes. Once it is recognized just how big of a hazard climate change is for progress against cancer care everywhere, it is important for oncologists to identify their sphere of influence and increase awareness among colleagues or nudge their institutions to be more environmentally responsible. Work to incorporate climate change in every aspect of your work.

Healio: Is there anything else that you would like to mention?

Nogueira: We all have a role to play in being the solution. It is important to note that communities targeted for marginalization suffer first and worst from the health hazards of climate change. If on top of being diagnosed with cancer, patients also have limited access to resources because of redlining, they may experience interpersonal racism when interacting with the health care system or experience increased exposure to health hazards — as the work of Robert D. Bullard, PhD, on environmental justice shows — then health outcomes are always going to be worse, and it is important for oncologists to understand the root causes of health disparities.

It is also important to understand that when an individual is closer to the problem, they are closer to the solution. We need to include these neglected voices in the conversation about solutions. We need to amplify the knowledge coming from these communities that have experienced the hazards firsthand and see the blind spots.

For more information:

Leticia M. Nogueira, PhD, MPH, can be reached at leticia.nogueira@cancer.org.