Is Climate Change Driving the Rise in Lung Cancer Among Nonsmokers?

Why Does Climate Change's Effect on Cancer Matter?

Lung cancer incidence among people who have never smoked is rising rapidly, and experts suggest climate change may play an important role. This striking new connection calls for us to rethink many aspects of human health, particularly environmental factors. The health effects of climate-driven air pollution, fires and natural disasters are becoming increasingly apparent, with potentially serious consequences, especially for vulnerable groups.

Now the Fifth Most Common Cause of Death

On January 9, 2024, Nature Reviews Clinical Oncology published a study noting that lung cancer in never-smokers (LCINS) differs histologically and epidemiologically from smoking-related cancers and often presents as adenocarcinoma. Particularly affecting women and people of Asian ancestry, this cancer is estimated to rank fifth among causes of cancer-related death worldwide.

To avoid misunderstanding, this distinction needs clarification:

• Lung cancer overall is the leading cause of cancer-related death worldwide.
• Lung cancer in never-smokers (LCINS) is the fifth most common cause of death among all cancer types.

A New Threat in Lung Cancer: Environmental Factors

At a session of the 2024 World Conference on Lung Cancer, experts discussed the effects of airborne carcinogens arising from climate change, vaping, cannabis use and military conflicts. They noted that these emerging risk factors, triggered by different causes, can sometimes be interconnected and highlight the importance of environmental hazards.

Dr. Leticia M. Nogueira, scientific director of health services research at the American Cancer Society, said that focusing on climate change and taking action at an individual level is a good starting point.

Long-Term Wildfire Exposure and Increased Cancer Risk

Climate change is associated with climate-related disasters such as severe hurricanes and more frequent wildfires. These events disrupt cancer care and lead to poorer patient outcomes. According to Dr. Nogueira, they play an important role in the rising incidence of lung cancer among people who have never smoked.

The Lancet Planetary Health published a population-based study that found increased risks of lung cancer and brain tumors with long-term wildfire exposure. Lung cancer incidence was 4.9% higher and brain tumor incidence 10% higher among people living 50 km from a wildfire area. The authors emphasized the global importance of these findings and the need to examine them carefully, given the projected effects of climate change on wildfire frequency and severity.

A Responsibility for Healthcare Workers: Climate-Friendly Healthcare

Dr. Nogueira reminded participants that healthcare is among the industries producing the most emissions and urged them to adopt environmentally friendly practices. She noted that emissions from the US healthcare system exceed the United Kingdom's total emissions and said every healthcare worker can support environmentally responsible practices in their workplace.

“There is something each of us can do here today: support environmentally friendly efforts at our institutions, participate in disaster preparedness and response, and raise awareness by documenting ongoing harms” she said. CA: A Cancer Journal for Clinicians published a commentary in which Dr. Nogueira and colleagues provided further information on the links between climate change and cancer, listing factors contributing to healthcare's greenhouse gas emissions and proposed intervention strategies.

We Have the Power to Build a Better World

Dr. Nogueira noted that action can be taken at both individual and institutional levels to mitigate environmental impacts, referring to Archimedes' famous words: “Give me a lever long enough, and I will move the world.” She said everyone has the power to create change and encouraged people to recognize where they have influence and use their levers.

This research highlights not only a scientific discovery but also the need for greater environmental awareness. Efforts by healthcare workers and health systems to reduce their contribution to climate change are essential for healthier future generations.