Potential Drivers of LCINS

The incidence of lung cancer in never-smokers (LCINS) is increasing, and experts think climate change may be driving this.

LCINS differs histologically and epidemiologically from smoking-related cancers, occurring almost always as adenocarcinomas and mostly affecting women and individuals of Asian ancestry, according to a study published in Nature Reviews Clinical Oncology in January 2024. Cases of LCINS are estimated to be the fifth most common cause of cancer-related deaths worldwide.

During a plenary session at the 2024 World Congress on Lung Cancer, experts addressed the known and suspected causes of LCINS, including fallout from climate change, vaping, cannabis use, and effects of airborne carcinogen exposures arising from military conflict. These potential culprits are varied and sometimes interrelated — and they underscore the need for continued emphasis on environmental hazards, the panelists agreed.

Focusing on climate change — and taking action at the individual level — is a good place to start, said Leticia M. Nogueira, PhD, scientific director of health services research in the Surveillance and Health Equity Science Department of the American Cancer Society.

Long-Term Exposure to Wildfires Linked to Increased Cancer Risk

Climate change is associated with climate-driven disasters such as more intense hurricanes and more frequent wildfires that can expose populations to environmental carcinogens, Nogueira explained.

Such weather events disrupt the care of patients with cancer and lead to poorer outcomes, according to her own research. They also contribute to the rising incidence of LCINS, she said.

In a population-based study published in The Lancet Planetary Health, long-term exposure to wildfires was associated with an increased risk for lung cancer and brain tumors. Individuals exposed to a wildfire within 50 km of their residential locations in the prior decade has a 4.9% relatively higher incidence of lung cancer and a 10% relatively higher incidence of brain tumors.

“These findings are relevant on a global scale given the anticipated effects of climate change on wildfire frequency and severity,” the authors concluded, noting the study limitations and the need for further research.

How Clinicians Can Help

Nogueira urged attendees to take action to help improve healthcare outcomes.

“Let’s not forget that the healthcare system is one of the most emission-intensive industries in the world. Emissions from the US healthcare system exceed emission from the entire UK, and we can be doing much better.

“There is something for each one of us here today to do: We can champion environmentally responsible efforts at our institutions, we can engage with disaster preparedness and response…and we can document ongoing suffering to increase awareness and incentivize action,” she said.

In a commentary published in CA: A Cancer Journal for Clinicians, Nogueira and her colleagues further addressed the links between climate change and cancer and listed various sources of greenhouse gas emissions and proposed interventions, including those associated with the healthcare industry.

“If you look at this list and say ‘No way — there is no chance my institution will do any of that,’ let me ask you something: Are you allowed to smoke on campus? How do you think that happened? How do you think that started?” she said, invoking Archimedes’ famous quote, ‘Give me a lever long enough, and I shall move the world.’

“You most certainly have the power to make a difference,” Nogueira said. “So recognize where your points of influence are – move your lever, move the world.”

Sharon Worcester, MA, is an award-winning medical journalist based in Birmingham, Alabama, writing for Medscape, MDedge, and other affiliate sites. She currently covers oncology, but she has also written on a variety of other medical specialties and healthcare topics. She can be reached at sworcester@mdedge.com or on Twitter: @SW_MedReporter.