Recurrence patterns among patients with sinonasal mucosal melanoma: A multi‐institutional study.

Objective: To evaluate recurrence patterns and survival after recurrence among patients with sinonasal mucosal melanoma (SNMM). Methods: This was a multi‐institutional retrospective review from seven U.S. institutions of patients with SNMM from 1991 to 2022. Recurrence was categorized as local, regional, distant, or multifocal. Kaplan‐Meier tests were used to evaluate disease‐free survival (DFS), overall survival (OS), and post‐recurrence survival (PRS) reported with standard errors (SE) and log‐rank testing used for comparison. Cox‐regression was further used, with hazard ratios (HR) and 95% confidence intervals (CI) reported. Results: Among 196 patients with SNMM, there were 146 patients with recurrence (74.5%). Among all patients, 60‐month DFS (SE) was 15.5% (2.9%), 60‐month OS (SE) was 44.7% (3.7%), mean age ± standard deviation at diagnosis was 69.7 ± 12.5 years, and 54.6% were female. In 26 patients who underwent primary treatment of the neck, 60‐month DFS did not differ from no treatment (p > 0.05). Isolated distant recurrence was most common (42.8%), followed by local (28.3%), multifocal (20.7%), and regional recurrence (8.3%). Among patients with regional recurrence in the neck, there was no 60‐month PRS benefit for patients undergoing salvage neck dissection or radiation (p > 0.05). Among patients with distant recurrence, only immunotherapy was associated with improved 12‐month PRS (HR = 0.32, 95% CI = 0.11–0.92, p = 0.034), and no treatment group was associated with improved 24‐ or 60‐month PRS (p > 0.05). Conclusion: SNMM is associated with a high recurrence rate and poor survival. Primary treatment of the neck was not associated with reduced recurrence, and immunotherapy for treatment of distant recurrence was associated with increased 12‐month PRS. [ABSTRACT FROM AUTHOR]