Patterns of Treatment Failure in Patients with Sinonasal Mucosal Melanoma.

BACKGROUND: Head and neck mucosal melanoma is a locally aggressive tumor with a high recurrence rate. The paranasal sinuses and nasal cavity are the most common primary tumor sites.

OBJECTIVE: The purpose of this retrospective study was to identify independent predictors of outcome in sinonasal mucosal melanoma (SNMM) and characterize the patterns of treatment failure.

METHODS: This study included 198 patients with SNMM who had been treated at The University of Texas MD Anderson Cancer Center from 1 January 1991 through 31 December 2016. The survival outcomes included overall survival (OS), disease-specific survival (DSS), disease-free survival (DFS), local recurrence-free survival, and distant metastasis-free survival. A stepwise regression analysis was used to assess associations in the multivariate models.

RESULTS: The 5-year OS, DSS, and DFS rates were 38, 58, and 27%, respectively. Independent predictors of poor OS and DSS were the paranasal sinuses as the primary tumor site [hazard ratio (HR) 1.73, 95% confidence interval (CI) 1.11-2.66; and HR 2.12, 95% CI 1.21-3.74, respectively] and the presence of distant metastases at presentation (HR 4.53, 95% CI 2.24-7.83; and HR 3.6, 95% CI 1.12-7.1). Recurrence occurred in 96 patients (48%). The most common cause of treatment failure was distant metastasis in 69 of 198 patients (35%), followed by local [36 (18%)] and regional [22 (11%)] recurrence.

CONCLUSION: The most common cause of treatment failure in SNMM is distant metastasis. The tumor site and the presence of metastatic disease at presentation were the only independent predictors of survival. These data can be used to inform quality improvement efforts and the counseling of high-risk SNMM patients.