Not all hematopoietic growth factors are created equal: should we gain information for their use with immunotherapy?

Myeloid growth factors, either granulocyte colony-stimulating factor (CSF) or granulocyte-macrophage CSF, are widely used to reduce the incidence and severity of chemotherapy-induced neutropenia by prophylactic or therapeutic administration. However, their activity in the novel therapeutic regimens, which often rely on the association between immunotherapy and chemotherapy, has not been thoroughly characterized yet. This paper presents some of the preclinical and clinical research regarding the putative interplay between myeloid growth factors and the immune system, advocating further studies to elucidate their potential positive or negative consequences on the outcomes when administered with immunotherapeutic agents.