Evolving Therapeutic Strategies in Mucosal Melanoma Have Not Improved Survival Over Five Decades

Mucosal melanoma represents a distinct minority of disease sites and portends a worse outcome. The ideal treatment and role of adjuvant therapy remains unknown at this time. We hypothesized that a combination of neoadjuvant and adjuvant therapies would improve survival in these aggressive melanomas. Our large, prospectively maintained melanoma database was queried for all patients diagnosed with mucosal melanoma. Over the past five decades, 227 patients were treated for mucosal melanoma. There were 82 patients with anorectal, 75 with sinonasal, and 70 with urogenital melanoma. Five-year overall survival and melanoma-specific survival for the entire cohort were 32.8 and 37.5 per cent, respectively, with median overall survival of 38.7 months. One hundred forty-two patients (63.8%) underwent adjuvant therapy and 15 were treated neoadjuvantly (6.6%). There was no survival difference by therapy type or timing, disease site, or decade of diagnosis. There was improved survival in patients undergoing multiple surgeries (Hazard Ratio [HR] 0.55, P = 0.0005). Patients receiving neoadjuvant therapy had significantly worse survival outcomes (HR 2.49, P = 0.013). Over the past five decades, improvements have not been seen in outcomes for mucosal melanoma. Although multiple surgical interventions portend a better outcome in patients with mucosal melanoma, adjuvant treatment decisions must be individualized.