COVID-19 associated with increased lung cancer risk in current smokers; spike protein drives tumorigenesis in mice

This research combined a retrospective cohort analysis with preclinical mechanistic studies. The human analysis used TriNetX database data from 166,807 current smokers, comparing COVID-19 survivors to propensity score-matched controls without COVID-19. The main finding was that COVID-19 was associated with a significantly increased risk of lung cancer in this population (RR 1.22; HR 1.50, P < 0.001). Preclinical studies in K18-hACE2TG mice exposed to intratracheal SARS-CoV-2 spike protein showed increased lung tumor burden (P < 0.001), while K18-hACE2TG/Tymp–/– mice showed no increase, suggesting a thymidine phosphorylase (TYMP)-dependent mechanism.

Safety and tolerability data were not reported for either the human cohort or animal studies. The research examined secondary outcomes including lung injury, inflammation, thrombosis, fibrosis, STAT3 activation, cytokine profiles, and ACE2 processing in vitro, though specific results for these endpoints were not detailed in the provided data.

Key limitations include the retrospective observational design of the human data, which cannot establish causality, and the use of preclinical mouse models that may not fully translate to human biology. The authors suggest TYMP represents a potential therapeutic target to mitigate long-term pulmonary consequences of COVID-19. Practice relevance is currently limited; these findings should be viewed as generating hypotheses for further investigation rather than guiding clinical decisions.