Background: Cutaneous melanoma, although less incident than other skin cancers, accounts for most deaths associated with these neoplasms, especially when diagnosed at advanced stages. Early detection is associated with better prognosis and reduced mortality; however, the incorporation of population screening strategies for melanoma remains controversial due to limited evidence regarding effectiveness, feasibility, and cost-effectiveness. In this context, epidemiological studies are essential to assess the real-world impact of early detection programs on incidence patterns, mortality, stage at diagnosis, and access to health services. Analysis of population data and time series before and after implementation of interventions inform public health decision-making and guide the formulation of evidence-based policies and guidelines. The Retrate Project, implemented by the Barretos Cancer Hospital (BCH) within the Brazilian Unified Health System (SUS), integrates opportunistic, targeted, and population-based strategies for skin cancer screening; nevertheless, its influence on melanoma epidemiological patterns has not yet been systematically evaluated. Objective: To analyze melanoma epidemiological patterns in the Barretos region (São Paulo), considering the Retrate Project implementation, and to evaluate its influence on incidence, mortality, clinicopathological characteristics, and the patient journey to diagnosis. Methods: Observational study divided into two phases. Phase I consists of a retrospective ecological epidemiological design with georeferencing and time-series analyses using data from the Barretos Population-Based Cancer Registry, the Hospital Cancer Registry of the Fundação Oncocentro de São Paulo, and the SUS Mortality Information System. Phase II is a retrospective cohort with clinical and demographic analysis of melanoma cases. In both phases, patients diagnosed through the Retrate Project strategies will be compared with those diagnosed by spontaneous demand at the BCH. Analyses will be structured into three periods: (1) 24 months preceding the COVID-19 pandemic (07/2017–06/2019), (2) 24 months preceding the Retrate Project implementation (07/2021–06/2023), and (3) 24 months during project execution (07/2023–06/2025). Preliminary results: Completed epidemiological analyses revealed temporal variations in melanoma incidence patterns in the Barretos region across the evaluated periods, as well as differences in the spatial distribution of cases among municipalities covered by the Population-Based Cancer Registry. Changes were observed in the clinicopathological profile of melanomas diagnosed during the Retrate Project implementation period, with a higher proportion of cases diagnosed at earlier stages compared with previous periods. Differences were also identified in the source of diagnoses, with a relative increase in cases originating from structured early-detection strategies compared with spontaneous demand. Analyses of melanoma-specific mortality, detailed geospatial patterns, and patient journey indicators are currently ongoing. Conclusion / Implications: Epidemiological evaluation of the impact of a screening program in a real-world implementation context within the SUS can generate relevant evidence to support public policies and guide national guidelines for melanoma screening in middle-income countries.

Study development flow