The dichotomy of neutrophil granulocytes in cancer.

Neutrophil granulocytes are known for decades as central effector cells of the innate immune system. Because of their ability to rapidly recognize, take up and eliminate pathogens, these cells ensure the survival of the host before the onset of adaptive immunity. In tumor immunology neutrophils have long been ignored or at least underestimated, because the field focused on adaptive and antigen-specific anti-tumor immunity with tumor antigens, dendritic cells and T cells as the main players. More recently, the role of inflammation during tumor initiation and progression has raised considerable interest in the field. It is not surprising that neutrophils as primary inflammatory cells have also entered the arena of the immunologic tumor host interaction.