Analysis of Failure in Patients with Sinonasal Mucosal Melanoma

Background: Sinonasal mucosal melanoma (SNMM) is a locally aggressive tumor with a high recurrence rate. The purpose of this study was to identify independent predictors of outcome and to characterize the patterns of failure.

Methods: This retrospective study investigated 96 patients with SNMM treated between 1985 and 2016 in MD Anderson Cancer Center. All patients were assessed for presence and type of recurrence. Univariate and multivariate analysis assessed associations of recurrence rates with survival outcomes.

Results: Five-year overall survival (OS), disease specific survival (DSS), and disease free survival (DFS) were 41%, 57%, and 49%, respectively. Independent predictors of OS and DSS were T4b classification, presence of dural invasion and presence of distant metastases at presentation. Recurrence occurred in 64% of the patients with a mean time to recurrence of 34 ± 4.5 months (range 7–181 months). The most common route of failure was distant metastasis (51%) followed by local (45%) and regional (20%) recurrences. T4a classification, absence of cavernous sinus invasion, and adjuvant therapy were associated with better DFS on multivariate analysis. Margin status and adjuvant therapy were independent predictors of distant metastases.

Conclusion: The clinical course of SNMM is aggressive. The most common pattern of failure is distant metastasis. Lower distant metastatic disease rates were associated with negative margin status and adjuvant treatment. These prognostic estimates should be considered when tailoring treatment options for patients with SNMM.