ChemoNETosis in Cancer: A Comprehensive Review of Treatment-Induced NET Formation and Therapeutic Consequences

ChemoNETosis represents a distinct form of therapy-induced innate immune activation, in which cytotoxic chemotherapy alters the tumor microenvironment (TME) in ways that attract and stimulate neutrophils, ultimately triggering the release of neutrophil extracellular traps (NETs). Unlike classical NETosis, which typically arises in response to infection or sterile inflammation, chemoNETosis is initiated by treatment-related danger signals and chemokine-cytokine loops that reshape the immune landscape and promote the formation of NET-rich metastatic niches. These NET structures serve not only as physical scaffolds but also as bioactive platforms enriched with proteases, reactive oxygen species, and enzymes capable of activating growth factors, collectively driving epithelial-mesenchymal transition, enhanced tumor cell plasticity, immune cell exclusion, changes in vascular permeability, and the development of chemotherapy resistance. While predominantly associated with tumor-promoting effects, chemoNETosis may, under specific genetic or metabolic conditions, contribute to antitumor responses, reflecting its context-dependent plasticity. In this review, we present what is, to our knowledge, the first in-depth synthesis of chemoNETosis across solid tumors, with a focus on key mechanistic nodes and translational perspectives.