SARS-CoV-2 Infection: A Possible Risk Factor for Incidence and Recurrence of Cancers

COVID-19 and malignancy can affect the susceptibility of one another. Clinically recovered COVID-19 individuals display immune abnormalities that persist several months after discharge. The lymphopenia-related immunosuppression, functional exhaustion of cytotoxic lymphocytes (such as CD8⁺ cytotoxic T-cells and natural killer cells), hyperinflammatory responses, oxidative stress, downregulation of interferon response, development of the myeloid-derived suppressor cells, downregulation of tumor suppressor proteins and perhaps reactivation of the latent oncogenic viruses may directly and/or indirectly play a role in the cancer development and recurrence in severe COVID-19 patients. SARS-CoV-2-infected malignant patients may be at higher risk of death of their cancer than SARS-CoV-2-uninfected patients with the same cancers. On the other side, the patients with some types of cancers may be more vulnerable to SARS-CoV-2 infection compared with the non-cancerous individuals, due to their immunocompromised state resulted from malignancy, chemotherapy, and other concomitant abnormalities as well as perhaps greater expression of angiotensin-converting enzyme 2. SARS-CoV-2-infected cancerous patients are unable to produce an effective anti-virus immune response and may exhibit more severe forms of COVID-19. This review described the possible impacts of SARS-CoV-2 infection on cancer development and recurrence, and the potential cancer impacts on COVID-19 development, while the possible interventions are highlighted.