Eosinophils and Lung Cancer: From Bench to Bedside

Int J Mol Sci. 2022 May 3;23(9):5066. doi: 10.3390/ijms23095066.


Eosinophils are rare, multifunctional granulocytes. Their growth, survival, and tissue migration mainly depend on interleukin (IL)-5 in physiological conditions and on IL-5 and IL-33 in inflammatory conditions. Preclinical evidence supports an immunological role for eosinophils as innate immune cells and as agents of the adaptive immune response. In addition to these data, several reports show a link between the outcomes of patients treated with immune checkpoint inhibitors (ICI) for advanced cancers and blood eosinophilia. In this review, we present, in the context of non-small cell lung cancer (NSCLC), the biological properties of eosinophils and their roles in homeostatic and pathological conditions, with a focus on their pro- and anti-tumorigenic effects. We examine the possible explanations for blood eosinophilia during NSCLC treatment with ICI. In particular, we discuss the value of eosinophils as a potential prognostic and predictive biomarker, highlighting the need for stronger clinical data. Finally, we conclude with perspectives on clinical and translational research topics on this subject.

Keywords: biomarkers; eosinophils; immunotherapy; non-small cell lung cancer; predictive value; prognostic value.

Publication types

  • Review

MeSH terms

  • Biomarkers
  • Carcinoma, Non-Small-Cell Lung* / pathology
  • Eosinophils / pathology
  • Humans
  • Immune Checkpoint Inhibitors
  • Immunotherapy
  • Lung Neoplasms* / pathology


  • Biomarkers
  • Immune Checkpoint Inhibitors

Grants and funding

This research received no external funding.