Respiratory viral infections prime accelerated lung cancer growth

# Respiratory viral infections prime accelerated lung cancer growth *Published: 2026 May 14* bioRxiv. 2025 Sep 03:2025.09.02.672566. doi: 10.1101/2025.09.02.672566. The COVID-19 pandemic has highlighted the long-term consequences of viral pneumonia, yet its impact on cancer development remains unclear. Here, we show that patients previously hospitalized with severe COVID-19 have an increased risk of subsequent lung cancer. Across multiple murine models, severe respiratory viral infections accelerated lung cancer growth, whereas vaccination mitigated infection-enhanced tumor progression. Mechanistically, prior viral pneumonia reprogrammed the lung into a pro-tumor microenvironment marked by the sustained accumulation of tumor-associated neutrophils and heightened immunosuppression. We observed persistent chromatin remodeling at key cytokine loci in immune and structural cells, linking inflammatory memory to tumor-promoting signals. Therapeutically, combined blockade of neutrophil recruitment and programmed death-ligand 1 (PD-L1) restored CD8+ T cell function and suppressed tumor growth. Together, these findings establish a causal link between prior viral pneumonia and lung tumorigenesis, underscoring the need for enhanced surveillance and targeted interventions to reduce post-COVID cancer risk. DOI: 10.1016/j.cell.2026.02.013