Cancer patients are considered more susceptible to the SARS-CoV-2 infection. Higher rates of respiratory failure and death were reported in cancer patients and COVID-19, compared with the general population. Among other measures deemed to protect this vulnerable subcategory, both ASCO and ESMO recommended the extension of G-CSF use, to include prophylactic administration in all patients receiving regimens with 10%-20% risk of febrile neutropenia (FN) and also in regimens with risk of FN <10%, if patients were considered with poor bone marrow reserve due to comorbidities or advanced age. However, accumulating data reported in several recent publications suggested a direct involvement of the high neutrophil count, due to G-CSF stimulation, in the development of the adult respiratory distress syndrome (ARDS), the hallmark of the severe COVID-19 disease. In addition, some recent evidences suggest that G-CSF may hamper the efficacy of the mRNA vaccine. This paper reviews the most important data reporting higher rates of respiratory failures and death associated with G-CSF treatment in cancer patients and SARS-CoV-2 infection. Therefore, we consider that the current recommendation of expanding the G-CSF use in cancer patients during the COVID-19 pandemic should be reconsidered. The most important protective measures for cancer patients remain specific vaccination and a rigorous compliance with the general protective measures, whereas the G-CSF should be administrated as traditionally recommended by the current guidelines.
Keywords: COVID-19, G-CSF, cancer, neutropenia