Mucosal Melanoma Clinical Management and Prognostic Implications: A Retrospective Cohort Study

Area of Science:

• Oncology
• Dermatology
• Pathology

Background:

• Mucosal melanoma (MM) is a rare subtype of melanoma affecting non-sun-exposed mucosal surfaces.
• MM presents unique diagnostic and management challenges compared to cutaneous melanoma.
• Understanding prognostic factors and genetic mutations is crucial for improving patient outcomes.

Purpose of the Study:

• To describe the experience with mucosal melanoma diagnosis, management, and outcomes at a tertiary hospital.
• To identify predictors of survival and characterize somatic mutations in a cohort of MM patients.
• To evaluate the impact of clinical and molecular factors on overall survival.

Main Methods:

• Registry-based cohort study of 35 MM patients diagnosed between 2012 and 2022.
• Retrospective analysis of somatic mutations in BRAF, NRAS, and c-KIT.
• Kaplan-Meier curves, log-rank tests, and Cox regression were used to analyze prognostic factors.

Main Results:

• The median age was 70 years, with 63% of patients being women; vulvovaginal MM was most common (48.6%).
• At diagnosis, 28.6% had lymph node involvement and 31.4% had distant metastasis.
• BRAF mutations were found in 9% and c-KIT mutations in 33% of tested patients. Lower stage, thinner Breslow depth, and surgical resection correlated with better survival.

Conclusions:

• Mucosal melanoma has an unfavorable prognosis, with a 2-year survival rate below 50%.
• Surgical resection and early disease stage are key positive prognostic factors.
• While standard treatment includes immunotherapy, targeted therapies for BRAF or c-KIT mutations warrant consideration.