Defining response-adapted surgery after neoadjuvant systemic therapy in sinonasal squamous cell carcinoma

BACKGROUND: Neoadjuvant systemic therapy combined with response-adapted surgery holds significant promise for improving oncologic and functional outcomes in head and neck cancer. Consistent and rigorous documentation is essential to evaluate this approach across disease sites. A system accounting for the complex anatomy of sinonasal tumors is currently lacking. We developed a framework to elucidate how neoadjuvant therapy impacts the extent and morbidity of surgery in sinonasal squamous cell carcinoma (SCC). METHODS AND RESULTS: A review of the medical literature highlighted a gap in research into response-adapted surgery for sinonasal malignancies. We developed a novel classification system to document resection at initial presentation and following neoadjuvant treatment. The framework is grounded in the surgical anatomy of the sinonasal region and weighs completeness with broad reproducibility to categorize adaptations according to (1) structures resected (2) exposure (3) reconstruction and (4) lymph node management. The surgical morbidity score was developed through a structured, iterative consensus process with a multidisciplinary expert panel. The final classification system was formally reviewed and endorsed by the institutional sinonasal tumor disease management team, establishing it as the standardized framework for documenting surgical outcomes in patients with SCC undergoing neoadjuvant therapy. CONCLUSIONS: The proposed system introduces the first response-adapted surgery classification to encompass patients with locoregionally advanced sinonasal SCC treated with neoadjuvant therapy prior to definitive surgical resection. By extending standardized terminology, this framework enhances communication within multidisciplinary teams, enables meaningful comparisons across published studies, and supports consistency in developing clinical trial endpoints seeking to balancing oncologic control and functional preservation.