Possibility of SARS-CoV-2 infection in metastatic microenvironment of cancer

According to a report from the World Health Organization, the mortality and severity rates among patients with cancer infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are significantly higher than those of individuals infected with SARS-CoV-2 without complications. Common and cancer-specific risk factors may be involved in the mortality and severity rates of coronavirus disease 2019 (COVID-19). Various factors have been determined to contribute to the aggravation of COVID-19 in patients with cancer. However, on the basis of current research, the factors involved in the aggravation of COVID-19 in patients with cancer have not been fully investigated. In the general course of treatment for patients with cancer, the detection of the formation of metastases in other organs is common. Therefore, the present study investigates the association between lung metastatic lesion formation and SARS-CoV-2 infectivity. On the basis of the results obtained, in the pulmonary micrometastatic niche of patients with ovarian cancer, alveolar epithelial stem-like cells adjacent to the ovarian cancer were observed. Moreover, it was revealed that angiotensin-converting enzyme 2, a host-side receptor for SARS-CoV-2, was expressed in alveolar epithelial stem-like cells adjacent to the ovarian cancer in the pulmonary micrometastatic niche. Furthermore, it was also observed that the SARS-CoV-2 spike glycoprotein receptor-binding domain binds to alveolar epithelial stem-like cells. In other words, it was suggested that patients with cancer and pulmonary micrometastases may be more susceptible to SARS-CoV-2. The prevention of de novo niche formation in metastatic disease may be a new strategy for the clinical treatment of COVID-19 for patients with cancer.