Dormant Breast Cancer Reawakened by Respiratory Viruses
In a groundbreaking study published in the journal "Cancer Discovery" in 2023, researchers led by Philipp S. Wild, Janine Altmüller, and others have discovered that respiratory viral infections, including SARS-CoV-2, can reactivate dormant metastatic breast cancer cells in the lungs.
The study, which used a mouse model called MA10, engineered to mimic COVID-19-like lung disease in mice, found that upon infection, SARS-CoV-2 led to an expansion of HER2-positive cells in pulmonary tissue. This expansion was accompanied by a robust inflammatory response within the lung tissue, with increased levels of pro-inflammatory cytokines IL-6 and interferon-alpha (IFNα).
The IL-6-driven inflammatory cascade may alter the lung microenvironment in ways that favor metastatic niche formation and cancer cell proliferation. The shift in marker expression suggests epithelial-mesenchymal plasticity, indicating dynamic phenotypic remodeling of disseminated cancer cells triggered by viral insults.
Detailed temporal analyses revealed a stepwise increase in the number and proliferative activity of HER2-positive cells. Epidemiological analyses revealed that breast cancer patients who developed COVID-19 exhibited a significantly higher hazard ratio for progression to metastatic lung disease. Furthermore, cancer survivors who tested positive for SARS-CoV-2 faced an elevated risk of all-cause and cancer-related mortality.
Understanding the molecular crosstalk between immune signaling and tumor cell dormancy could unveil new targets for preventing metastasis post-infection. The findings prompt urgent questions regarding vaccination strategies, antiviral therapies, and immunomodulatory treatments to mitigate such risks in cancer survivors.
This research underscores the critical importance of managing viral infections in vulnerable populations to suppress cancer reactivation and improve long-term survival outcomes. Studies like this highlight previously unrecognized intersections between infectious diseases and oncology, demanding interdisciplinary approaches to unravel the complex biological networks at play.
Clinicians and researchers should consider the potential for respiratory viruses to act as catalysts in cancer progression, particularly in tissues prone to metastatic seeding such as the lungs. The advancement of this fundamental knowledge of metastatic cancer biology has immediate translational resonance, paving the way for future research and potential interventions.
