Risk for COVID-19 infection in patients with tobacco smoke-associated cancers of the upper and lower airway

PURPOSE: Cancer patients are regarded as a group at risk for both COVID-19 infection and severe clinical course because of advanced age, comorbidities and iatrogenic immune impairment. Among them, patients with cancer of the upper and lower airways share other risk factors, mostly related to tobacco-smoke exposure, including male gender, airway epithelial damages, chronic obstructive respiratory disease (COPD), cardiovascular and cerebrovascular diseases. Clinical and pathophysiological factors shared by these conditions are reviewed. METHODS: Review of the published literature since the beginning of 2020. RESULTS: COVID-19 is a respiratory infectious disease and SARS-CoV-2 replication and shedding occurs in nasal and bronchial epithelial respiratory cells through the interaction with ACE2 and TMPRSS2 receptors, both overexpressed in smokers and former smokers. Tobacco-smoke airway exposure is also characterized by a chronic inflammation with activation of inflammatory cells and cytokine release including interleukin-6 (IL-6). A high release of cytokine in response to viral infection is documented in COVID-19 patients with adverse clinical outcomes and IL-6 is a key element of the cytokine storm syndrome leading to multi-organ damage. CONCLUSIONS: Patients with cancers of the upper and lower airways might be at increased risk of infection, morbidity and mortality from COVID-19 also because of tobacco exposure, a key factor in triggering inflammation, immunity and cancer.