Neoadjuvant immunotherapy in head and neck cancer: Rationale, current evidence and future perspective.

Immune-checkpoint inhibitors (ICIs) have shown to improve survival in the first- and second-line settings of recurrent/metastatic squamous cell carcinoma of the head and neck (SCCHN). In the past two years more than a dozen neoadjuvant IO studies have been reported in SCCHN, demonstrating the feasibility of one or a few doses of single agent or combination ICIs. This approach seems safe with no surgical delays due to toxicity in most of the studies with no new safety signals. Efficacy in terms of pathologic response appears promising both with single-agent ICIs and especially with chemo-IO combinations. The scientific rationale and current clinical evidence of neoadjuvant IO trials in SCCHN will be reviewed, including currently debated aspects such as the methodology for radiological and pathological evaluation as well as types and criteria for biomarker use in this setting. Finally, the future perspective of neoadjuvant IO in SCCHN will be approached.