Epidemiology, clinical characteristics, and survival of acral and non-acral melanoma in Colombia

BACKGROUND: Although the incidence of cutaneous melanoma in Colombia is lower than in predominantly Caucasian populations, survival outcomes remain comparatively poorer. This disparity may be partly explained by the high proportion of melanomas arising in acral sites. However, no multicenter studies in Colombia have systematically compared the clinical behavior of acral versus non-acral melanomas. OBJECTIVE: To compare the clinical and epidemiological characteristics, as well as 5-year overall survival (OS), between acral and non-acral melanoma cases across six Colombian cities. MATERIALS AND METHODS: We conducted a retrospective, multicenter study of incident malignant cutaneous melanoma cases diagnosed between 2013 and 2019, using data from five population-based cancer registries and an institutional cancer registry. Exact or trend tests were used for categorical variables, and nonparametric tests for quantitative variables. Survival analysis was performed using the Kaplan-Meier method and Cox proportional hazards regression. RESULTS: A total of 1408 cases were included; 32% were acral melanomas. Compared with non-acral tumors, acral melanomas were significantly thicker (4.0 mm vs. 1.8 mm), more frequently ulcerated (70% vs. 42%), more mitotically active (87% vs. 75%), and more often diagnosed at advanced stages (52% vs. 37%). Survival analysis included 854 patients. Five-year OS was markedly lower for acral melanoma (42.4% vs. 64.8%), particularly for tumors located on the foot (38.1%). Older age (≥65 years), male sex, advanced stage, and acral lentiginous or nodular subtypes were also associated with poorer OS. CONCLUSION: In Colombia, melanoma displays distinct clinical and histopathological patterns, characterized by a high burden of aggressive acral tumors and frequent late-stage diagnoses, factors that likely underpin the worse OS observed. These findings underscore the urgent need to tailor early detection strategies to the local epidemiology of melanoma and to strengthen public health policies aimed at improving timely diagnosis and management.