Resectable Sinonasal Mucosal Melanoma in the Immunotherapy Era: Upfront Surgery vs. Neoadjuvant Therapy

Objective: We aim to evaluate outcomes for patients with resectable SNMM treated in the immunotherapy era. Methods: Thirty-seven patients with resectable SNM were identified using our institutional database between 2016 and 2023. Results: Patients receiving neoadjuvant Ipi/Nivo (46%, n = 17) were more likely to have disease involving the sinuses and/or the skull base (71% vs. 35%, p = 0.05). The overall response rate to Ipi/Nivo was 24%. Two-year LRFS from the start of therapy was 63%, and from the end of local therapy was 78%. Two-year PFS was 49%. The patients who received Ipi/Nivo with evidence of response (n = 4, 24%) had better PFS (2-year PFS 100% vs. 15%, p = 0.02) and LRFS (2-year LRFS 100% vs. 31%, p = 0.08). Conclusions: Outcomes for resectable SNMM patients continue to be poor in the immunotherapy era. In the context of selection bias, neoadjuvant Ipi/Nivo was not associated with better outcomes in all-comers. However, those with evidence of response to Ipi/Nivo had better prognosis.