COVID, the Flu, and Other Viral Infections Can Re-Awaken Dormant Breast Cancer Cells

Strategic Insights -

In a groundbreaking study on mice, researchers have discovered that common respiratory infections, such as COVID, the flu, and other viral infections, can re-awaken dormant breast cancer cells, leading to a surge in cancer activity. This finding has significant implications for breast cancer survivors, as it suggests that protecting themselves from respiratory infections may be crucial in preventing cancer relapses.

Key Takeaways:

  • The study used mice engineered with breast cancer cells that mimicked the behavior of dormant human cancer cells hiding in the lungs.
  • Researchers found that within days of infection, the once-quiet cancer cells started to wake up, multiply rapidly, and form new metastatic lesions in the lung.
  • The process was driven by the immune response, specifically the surge in interleukin-6 (IL-6) levels, which creates a perfect storm for dormant cancer cells to shift from a sleepy, inactive mode to a highly active state.
  • When IL-6 was disabled in the mice, the dormant cancer cells did not multiply nearly as much when the viral infection was introduced.
  • The reawakening of cancer cells doesn't last forever, but the danger hasn't passed, as dormant cells in the lungs can remain primed to begin multiplying again once triggered.
  • The study hints that helper T cells shield cancer cells from other immune attacks, turning them from destroyers into guardians.
  • The research team also found that cancer patients, especially those who'd recently had respiratory infections, faced nearly double the risk of dying from cancer compared to those who did not get infected.
  • This pattern was clearest in the months after infection, matching exactly what was seen in the mouse studies.
  • The findings highlight the importance of protecting breast cancer survivors from respiratory infections to lower the risk of setting off dormant cancer cells that could lead to life-threatening metastasis.

Statistics:

  • Cancer patients who'd recently had respiratory infections faced a nearly double risk of dying from cancer compared to those who did not get infected (Source: Study data from thousands of cancer survivors in the UK and US during the COVID-19 pandemic).
  • Within days of infection, the once-quiet cancer cells multiplied rapidly and formed new metastatic lesions in the lung (Source: Mouse study).
  • Within about two weeks of infection, the burst of activity settled down, and the cancer cells often returned to a dormant state (Source: Mouse study).

Sources:

  • The Conversation -- UK -- By Justin Stebbing, Professor of Biomedical Sciences, Anglia Ruskin University (Source: https://theconversation.com/covid-the-flu-and-other-viral-infections-can-re-awaken-dormant-breast-cancer-cells-new-study-in-mice-shows-262464)
  • Study data from thousands of cancer survivors in the UK and US during the COVID-19 pandemic (Source: Study cited in The Conversation article)