Mucosal melanoma in 1481 patients in the Netherlands. An overview of metastatic patterns, main driver mutations and the efficacy of therapeutic strategies

Mucosal melanomas are a rare melanoma subtype with poor prognosis. This project aimed to identify the main driver mutations of the different mucosal melanomas and to evaluate the efficacy of targeted/immunotherapies in patients with metastatic disease in current practice. In addition, the baseline clinicopathological characteristics, metastatic patterns, and primary treatment strategies and survival of mucosal melanoma subtypes were studied. The Dutch nationwide pathology databank (Palga) and the Netherlands Comprehensive Cancer Organisation (IKNL) were queried for all patients with a diagnosis of mucosal melanoma (1989-2021). The dataset included a total of 1481 patients. Mutation status was assessed in 397 patients and in 170 patients (43%) a driver mutation was discovered. Patients with metastatic disease who received targeted/immunotherapy did show a better survival. The liver and lung were the predominant locations of the first metastasis. The data in the present study implies that patients with metastatic disease mucosal melanoma might benefit from targeted/immunotherapies. Molecular analysis should be considered in these patients.