Outcomes of Curative‐Intent Endoscopic Resection Combined With Adjuvant Immune Checkpoint Inhibition for Resectable Sinonasal Mucosal Melanoma

BACKGROUND: Evidence for adjuvant immune checkpoint inhibitor (ICI) therapy after curative-intent resection of sinonasal mucosal melanoma (SNMM) is limited. METHODS: We retrospectively reviewed 11 patients with resectable N0M0 SNMM who underwent curative-intent endoscopic resection followed by adjuvant ICI. Outcomes and immune-related adverse events (irAEs) were summarized descriptively, and univariable Cox proportional hazards regression was performed as an exploratory analysis to explore potential risk factors. RESULTS: The 1- and 3-year overall survival rates were 100.0% and 90.0%; recurrence-free survival rates were 45.5% and 0%. Any-grade and grade ≥ 3 irAEs occurred in 8 of 11 patients (72.7%) and 3 patients (27.3%). T4a disease was associated with shorter recurrence-free survival than T3 disease (hazard ratio, 13.96; 95% confidence interval, 1.24-157.50; p = 0.033). CONCLUSIONS: Recurrence was frequent and early, whereas overall survival remained preserved. Although efficacy cannot be inferred without a comparator, these data support multicenter evaluation of treatment sequencing and risk stratification.