New research indicates that severe cases of COVID-19 or influenza can alter lung immune cells, potentially increasing cancer risk months or years afterward. The study, conducted by scientists at the University of Virginia, highlights the role of chronic inflammation in this process and emphasizes vaccination as a preventive measure. Findings suggest closer monitoring for affected patients to enable early detection.
Researchers from UVA Health's Beirne B. Carter Center for Immunology Research and the UVA Comprehensive Cancer Center have uncovered links between severe respiratory infections and heightened lung cancer risk. Led by Jie Sun, PhD, from UVA School of Medicine, the team examined how infections like COVID-19 and influenza affect lung health over time.
The study, published in the journal Cell, analyzed both mouse models and human patient data. In mice, severe lung infections led to changes in immune cells such as neutrophils and macrophages, fostering a persistent inflammatory environment that supports tumor growth. These alterations also impacted epithelial cells in the lungs and air sacs. Human data showed a 1.24-fold increase in lung cancer diagnoses among those hospitalized for COVID-19, independent of smoking history or other comorbidities.
"A bad case of COVID or flu can leave the lungs in a long-lasting 'inflamed' state that makes it easier for cancer to take hold later," Sun stated. He noted that vaccination largely prevents these harmful changes by enabling a more effective immune response and reducing infection severity.
Mild infections did not elevate risk and even showed a slight decrease in lung cancer incidence. However, the researchers urge enhanced surveillance for survivors of severe viral pneumonia, especially those with smoking histories. "These findings have important immediate implications for how we monitor patients after severe respiratory viral infection," said collaborator Jeffrey Sturek, MD, PhD.
The work suggests that vaccines may offer indirect protection against cancer by averting severe illness fallout. Sun and colleagues aim to develop targeted prevention and treatment strategies for infection-related lung cancer.
