Presentation (CTI)

OBJECTIVES: Mucosal melanoma (MM) is a rare subtype of melanoma arising from melanocytes in mucous membranes and accounts for approximately 1.2% of melanomas with worse prognosis than cutaneous melanomas. We examined patient flow and treatment patterns across lines of therapy (LOTs) from diagnosis to death. Curative surgery was defined as a site-specific resection of the primary tumor per the Surveillance, Epidemiology, and End Results (SEER) database. Resectable tumors were tumors classified as "Localized" or "Regional, regional lymph nodes only".
METHODS: We utilized the SEER-Medicare-linked database, covering data from 01JAN2014-31DEC2021, with follow-up through 31DEC2023. Patients were included in the study if they had ≥1 diagnosis of MM using SEER histology codes and International Classification of Diseases for Oncology, 3^rd Edition (ICD-O-3) topography codes, and ≥65 years of age at the initial MM diagnosis.
RESULTS: In the study period, 1,362 patients had ≥1 MM diagnosis claim at age 65+ years at their initial diagnosis. Local, regional, and distant tumors were 43.75%, 50.04%, and 6.21% respectively. Among the 1,362 patients, 618 (45.37%) were found to have a resectable tumor. Of those, 44.66% received curative surgery and 61.23% received systemic therapy in the adjuvant setting (<90 days after surgery). Patients receiving their first LOT ≥90 days after surgery totaled 61.68%. Of the 55.34% of patients who did not receive surgery, 58.47% received systemic therapy as their first LOT. Among the 744 patients (54.63%) with a non-resectable tumor, 61.00% received systemic therapy as their first LOT.
CONCLUSIONS: In this cohort of older adults with MM, less than half of patients with resectable disease received potentially curative surgery, and a substantial proportion did not receive any systemic therapy. These findings highlight real-world gaps in the application of beneficial treatments for MM and underscore the need for improved strategies.