Population-based incidence and melanoma-specific survival of cutaneous malignant melanoma in a Colombian population 2000-2009

Background Demographic, clinical, and morphological characteristics of cutaneous melanoma are unknown for the Colombian population. We aim to provide these characteristics as well as population-based incidence and survival data. Methods All patients with an invasive cutaneous melanoma diagnosed in the period 2000-2009 registered in the population-based cancer registry of the metropolitan area of Bucaramanga were included for analysis (n = 169). Age-standardized incidence rates were calculated and melanoma-specific and overall survival estimated with follow-up until June 9, 2016, using Kaplan-Meier methodology, stratifying for gender, anatomical localization, and type of affiliation to the social security system. Results The age-standardized melanoma incidence rate was 1.7 per 100,000, with lower limbs being the most affected body sites (42.6% of all melanomas). A high proportion of melanomas presented on the plants or palms (16%) and under the nails (7.1%); at least 24.3% of melanomas were ulcerated, and 21.1% had a Breslow thickness more than 2 mm. Melanoma-specific 5-year survival was 79.3%, with worst survival for melanomas localized on the plants (64.6%) and subungual areas (55.6%). Affiliation to the subsidized type of affiliation to the social security system was statistically significantly (P = 0.003) associated with poorer survival (68.8%) compared to the special regimes (95.8%). Conclusions Melanoma is a relatively rare cancer in Colombia with mainly the acral sites, high proportion of thick and ulcerated melanomas, and relatively poor survival being distinct features, indicating the need for tailor-made primary and secondary prevention strategies. Better training of pathologists in the difficult field of melanoma would improve precision of available data.