Photo Credit: ALIOUI Mohammed Elamine

This study underscores the potential of complete primary tumor resection to reverse neutrophilia, alleviate neutrophil-driven systemic immunosuppression, and enhance systemic anti-tumor immunity, offering valuable insights for the effectiveness of neoadjuvant immunotherapy strategies in the context of tumor progression.

The following is a summary of “Complete tumor resection reverses neutrophilia-associated suppression of systemic anti-tumor immunity,” published in the January 2024 issue of Oncology by Kaskas et al.

In this study, researchers investigated the role of circulating neutrophils in contributing to systemic immunosuppression associated with tumor progression, particularly their impact on anti-tumor immunity. Using a murine model of oral cancers, the study group observed the accumulation of Ly6G+ neutrophilic cells in the periphery, correlating with increased plasma G-CSF concentration. These circulating neutrophils exhibited functional immunosuppression. 

Notably, complete surgical removal of the primary tumor reversed the observed neutrophilia, restoring neutrophil frequencies to baseline within 21 days. Functional assays demonstrated a marked enhancement in systemic anti-tumor immunity post-tumor resection, an effect reproducible through selective neutrophil depletion. Their findings highlight the potential of complete primary tumor resection to reverse neutrophilia linked to tumor progression and enhance systemic anti-tumor immune responses. This insight suggests that alleviating neutrophil-driven systemic immunosuppression may contribute to the clinical benefits observed with neoadjuvant immunotherapy strategies.

This research addresses whether peripheral neutrophils, known for their immunosuppressive role in tumor microenvironments, play a similar role in systemic immunosuppression. Utilizing a murine model of oral cancers, investigators identified Ly6G⁺ neutrophils accumulating in the periphery during tumor progression. The association with increased plasma G-CSF concentration and their functional immunosuppressive effects raised questions about their systemic impact. Strikingly, complete surgical removal of the primary tumor reversed the observed neutrophilia and led to a significant enhancement in systemic anti-tumor immunity. This novel understanding suggests that the relief of neutrophil-driven immunosuppression through primary tumor resection may contribute substantially to the success of neoadjuvant immunotherapy strategies.

Source: sciencedirect.com/science/article/abs/pii/S136883752400023X