Induction therapy in advanced sinonasal cancers: outcomes, selection, and preservation

Sinonasal malignancies are rare, biologically heterogeneous tumors that frequently present at an advanced stage with involvement of critical structures such as the orbit and skull base. Historically, management relied on radical surgical resection followed by adjuvant radiotherapy, often resulting in substantial morbidity and modest long-term survival. Over the past two decades, induction systemic therapies have emerged as integral components of multimodality treatment for selected patients with locally advanced disease. Induction strategies, initially centered on cytotoxic chemotherapy and more recently expanded to include immunotherapy, have enabled early cytoreduction, treatment of occult micrometastatic disease, and assessment of tumor biology. Across major sinonasal tumor subtypes, response to induction therapy has consistently demonstrated prognostic value and has informed response-adapted treatment selection, allowing for de-escalation of surgical extent and improved preservation of the orbit, skull base, and adjacent neurovascular structures without compromising oncologic outcomes. This review provides a contemporary synthesis of evidence supporting induction-based approaches in sinonasal squamous cell carcinoma, sinonasal undifferentiated carcinoma, olfactory neuroblastoma, NUT carcinoma, SMARCB1-deficient sinonasal carcinoma, and sinonasal mucosal melanoma, with emphasis on histology-specific treatment responsiveness, the evolving role of induction immunotherapy, and the impact of induction therapy on surgical decision-making.