Severe COVID-19 (or flu) may leave a hidden scar in the lungs - one that quietly fuels lung cancer growth.
A new preprint - Qian et al., 2025 - shows the first direct evidence of this link. The key points🧵
A new preprint - Qian et al., 2025 - shows the first direct evidence of this link. The key points🧵
https://twitter.com/vipintukur/status/1965057389239177302
Human data.
In a cohort of 44M+ people, those hospitalized with severe COVID-19 had a 19% higher risk of being diagnosed with lung cancer compared to uninfected controls!
Mild infections didn’t carry this risk - it’s the severity that matters.
In a cohort of 44M+ people, those hospitalized with severe COVID-19 had a 19% higher risk of being diagnosed with lung cancer compared to uninfected controls!
Mild infections didn’t carry this risk - it’s the severity that matters.
Animal models.
Mice that had recovered from severe COVID-19 or flu showed faster tumor growth and worse survival after tumor initiation.
The effect persisted for weeks to months after the virus was cleared.
Mice that had recovered from severe COVID-19 or flu showed faster tumor growth and worse survival after tumor initiation.
The effect persisted for weeks to months after the virus was cleared.
What’s happening in the lungs?
Severe viral pneumonia doesn’t just leave scar tissue. It rewires the lung environment.
Special neutrophils (SiglecFhi) accumulate and promote tumor growth.
CD8⁺ T cells - the cancer-killing army - become exhausted.
Lung epithelial cells get stuck in a risky in-between state, more prone to transformation.
Severe viral pneumonia doesn’t just leave scar tissue. It rewires the lung environment.
Special neutrophils (SiglecFhi) accumulate and promote tumor growth.
CD8⁺ T cells - the cancer-killing army - become exhausted.
Lung epithelial cells get stuck in a risky in-between state, more prone to transformation.
Epigenetic memory of inflammation.
After infection, DNA in lung cells stays more open at cytokine genes (IL-6, G-CSF, TNF).
That keeps the lung in a pro-tumor mode - easier recruitment of harmful neutrophils, weaker immune surveillance.
After infection, DNA in lung cells stays more open at cytokine genes (IL-6, G-CSF, TNF).
That keeps the lung in a pro-tumor mode - easier recruitment of harmful neutrophils, weaker immune surveillance.
How long does this last?
The study doesn’t show a clear end point.
In mice, the effect persists for at least 2 months (equivalent to several years in humans).
Authors write this inflammatory memory may last months to years - which means survivors need long-term monitoring.
The study doesn’t show a clear end point.
In mice, the effect persists for at least 2 months (equivalent to several years in humans).
Authors write this inflammatory memory may last months to years - which means survivors need long-term monitoring.
Protection.
In mice, mRNA vaccination against SARS-CoV-2 prevented the tumor-promoting effect - tumor growth looked like in uninfected animals.
Mild infections alone didn’t accelerate tumors.
Vaccination may indirectly protect against cancer by preventing severe disease.
In mice, mRNA vaccination against SARS-CoV-2 prevented the tumor-promoting effect - tumor growth looked like in uninfected animals.
Mild infections alone didn’t accelerate tumors.
Vaccination may indirectly protect against cancer by preventing severe disease.
Therapeutic angle.
Blocking neutrophils (CXCR2 inhibitor) + blocking PD-L1 worked synergistically.
Fewer harmful neutrophils, more active CD8⁺ T cells, less tumor growth.
Blocking neutrophils (CXCR2 inhibitor) + blocking PD-L1 worked synergistically.
Fewer harmful neutrophils, more active CD8⁺ T cells, less tumor growth.
Sum:
Severe viral pneumonia (COVID-19, flu) can prime the lungs for cancer - not immediately, but months or even years later.
That means -
Survivors of severe infection may need closer cancer surveillance
Preventing severe infections (by vacc) isn’t just about avoiding ICU…it may also be about preventing cancer.
Severe viral pneumonia (COVID-19, flu) can prime the lungs for cancer - not immediately, but months or even years later.
That means -
Survivors of severe infection may need closer cancer surveillance
Preventing severe infections (by vacc) isn’t just about avoiding ICU…it may also be about preventing cancer.
This is a preprint, not yet peer-reviewed.
Qian at al. 2025, Respiratory viral infections prime accelerated lung cancer growth. biorxiv.org/content/10.110…
Qian at al. 2025, Respiratory viral infections prime accelerated lung cancer growth. biorxiv.org/content/10.110…
• • •
Missing some Tweet in this thread? You can try to
force a refresh
