The secondary outcome was defined as tumor recurrence-free survival (RFS) on the basis of the time from the initial diagnosis to the time of tumor recurrence or the detection of locoregional or distant metastases after oncological treatment of the primary tumor. The primary outcome was OS, calculated on the basis of the follow-up time between admission to the cohort and the date of the event (all-cause mortality) or censoring. To obtain a power of 80% and a significance of 95%, a minimum sample size of 680 patients was calculated.

9, 12 The outcome of 5-year mortality was used for the variables of high-medium socioeconomic level compared with low (58% v 75%), presence of ulceration (9% v 38%), and Breslow <0.8 (5% v 15%). 22 The assumptions for the calculation were based on the estimates reported in the literature.

The sample size to determine prognostic factors was based on the method described by Lachin et al. Inclusion criteria were age older than 18 years and malignant melanoma histologically confirmed and clinical stage 0-III according to 8th edition American Joint Committee on Cancer system. Recruitment was performed from January 2011 to December 2021. Researchers from 16 health institutions of the country belonging to the national health system, none of them private, participated in this study. Given the lack of consolidated local data, the Asociacion Colombiana de Hematologia y Oncologia (ACHO) developed the Epidemiological Registry of Malignant Melanoma in Colombia (REMMEC), intending to characterize the population and establish clinical outcomes and related prognostic factors in patients with early malignant melanoma in Colombia.Īn analytical observational cohort study was carried out on the basis of the REMMEC registry, which was generated by the ACHO. 12- 14 These strategies have improved patient survival and reduced surgical treatment morbidity. Regarding the approach to high-risk melanoma with locoregional involvement, important advances have been made recently, such as the administration of adjuvant treatment with immune checkpoint inhibitors or anti-BRAF/anti–MEK therapy, 6- 11 as well as the reassessment of the therapeutic value of lymphadenectomy. 3- 5 However, there is a lack of information regarding the behavior of this neoplasia in Latin America, specifically in the Colombian population, which features a process of miscegenation and specific sociodemographic conditions, which could determine a set of prognostic factors different from those historically described. 3- 5 The risk factors usually described are age, male sex, presence of ulceration on histology, tumor thickness, histological type, treatment received, and tumor staging. Given the lethality of the neoplasm, it has been a permanent interest to establish prognostic factors in patients with melanoma and to apply strategies for modifying the clinical course of the disease and increasing overall survival (OS). Despite the difficulties, it is important to continue with this research and to have longer follow-up times, to achieve more information and greater precision of the collected data.

Our findings offer support for clinical decision making and to generate specific strategies for Colombian patients. Local information on the characteristics of patients with early melanoma has been limited.

Matilde michielin