Ipenburg NA, et al. - The present study was undertaken to externally validate the recently developed prognostic model by the European Organisation for Research and Treatment of Cancer (EORTC), that include Breslow thickness, ulceration and site of the primary tumor. Further, researchers examined if the addition of other prognostic factors improves its performance. In this retrospective single-institution study of 4235 patients with sentinel node-negative cutaneous melanoma, the EORTC prognostic model was validated for recurrence-free and melanoma-specific survival. Only marginal improvement in the model was noted with the addition of other prognostic factors. Findings support the utility of the validated EORTC model for personalizing follow-up and selecting high-risk patients for trials of adjuvant systemic therapy.