Development and validation of two online dynamic nomograms for patients with non‐distant metastatic cutaneous melanoma based on surgical approaches

BACKGROUND AND OBJECTIVES: Surgery is an essential treatment for non‐distant metastatic cutaneous melanoma (NMCM). We aim to construct and validate prognostic nomograms based on surgical approaches and the clinicopathological characteristics of NMCM patients. METHODS: Data of patients diagnosed with cutaneous melanoma from 2004 to 2015 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. Two online nomograms were constructed to predict the 3, 5‐year melanoma‐specific survival (MSS) for NMCM patients based on the surgical approaches. These nomograms were evaluated by the dynamic Harrell's concordance index (C‐index), decision curve analysis and clinical impact curve. Both internal and external data verification were conducted. RESULTS: A total of 14,091 NMCM cases were included in this study. The C‐index of the nomograms for the excisional surgery group and amputation group were 0.818 and 0.806, respectively, and 0.763 and 0.731, respectively, in our hospital data validation. After internal and bootstrap verification, our two nomograms showed good accuracy and practicality. CONCLUSION: NMCM patients exhibited equal survival rates independent of resection margin size, while those who needed amputation had worse survival rates. We generated two online nomograms distinguished by surgical approach to predict NMCM patient survival based on clinicopathological characteristics.