Severe Respiratory Infections Linked to Subsequent Lung Cancer

According to researchers led by an investigator from the UVA School of Medicine, chronic inflammation in the lungs left behind by severe COVID-19, influenza, or pneumonia infections may increase the risk for lung cancer down the road.

Jie Sun, PhD, and his colleagues arrived at that finding after looking at the effects of severe lung infections in both mice and humans. Results showed mice who experienced these infections exhibited major changes in neutrophils and macrophages that led to a persistent inflammatory environment supporting cancer growth. Changes were seen in epithelial cells as well.

Mice with these changes were more likely to develop lung cancer and die from it, and an analysis of patient data revealed a similar pattern in humans.

Specifically, patients who had been hospitalized with COVID-19 had a 1.24-fold increase in the incidence of lung cancer when compared to those who had not been hospitalized. The elevated risk held true even after the findings were adjusted to take factors like smoking and comorbidities into account.

The good news from the study is that vaccination appeared to mitigate the risk, most likely by helping the immune system respond more effectively to infections and reducing the overall severity of the disease. Patients in the study who had only mild infections with COVID-19 actually had a slightly decreased risk of lung cancer going forward.

Still, the authors believe new strategies should be developed to prevent or treat lung cancer linked to severe respiratory infections. These strategies might even include offering these patients the same access to routine CT screening as is now offered to smokers.

“Our goal is to help doctors identify who may be at higher risk of lung cancer after a severe infection and develop targeted ways to prevent and treat lung cancer after prior pneumonia,” said Dr. Sun. “We also believe that vaccines don’t just prevent acute hospitalization after contracting the virus. They may also reduce the long-term fallout of severe infection, including the kind of immune scarring that can increase cancer risk.”

The study was published in Cell. 

Highlighted in RC Buzz March 30, 2026