Mucosal melanoma of the head and neck: a population-based study from Slovenia, 1985-2013.

Objectives: To assess the incidence and to review experience with the treatment of mucosal melanoma of the head and neck (MMHN) in Slovenia between 1985 and 2013.

Methods: The National Cancer Registry database and clinical records with outcome data of identified patients treated during the period 1985-2013 in Slovenia were reviewed.

Results: In a 29-year period, 61 patients with MMHN were identified, representing 0.5 % of all head and neck malignant tumors and 42 % of all mucosal melanomas in Slovenia. 72 % originated in the sinonasal tract and were predominantly (78 %) diagnosed as a local disease. Regional metastases at diagnosis were more frequent in patients with oral/oropharyngeal primary (44 %; sinonasal MMHN 11 %, p = 0.006). Curative intent treatment was given to 48 (79 %) patients. The overall survival (OS) rates at 2 and 5 years for the whole cohort were 43 % and 18 %, respectively, and for the curative intent group 53 % and 24 %, respectively. In the latter group, multivariate analyses showed postoperative radiotherapy (PORT) to be predictive for locoregional control (LRC) (hazard ratios [HR] for surgery with PORT vs. surgery alone: 1.0 vs. 3.9, p = 0.037), whereas only the World Health Organization performance status (HR for grade 0 vs. grade 1 vs. grade >1: 1.0 (p = 0.022) vs. 1.2 (p = 0.640) vs. 7.7 (p = 0.008)) significantly influenced OS.

Conclusions: MMHN is a rare tumor with a poor prognosis. Combination of surgery and PORT offers the best prospects for LRC but without improvement of OS. Due to potential toxicity of high-dose RT such treatment is indicated in patients in whom LRC outweighs the risks of serious adverse effects.