Predictive and Prognostic Value of BRAF and NRAS Mutation of 159 Sentinel Lymph Node Cases in Melanoma—A Retrospective Single-Institute Study

SIMPLE SUMMARY: Sentinel lymph node (SLN) status is still the most important prognostic factor for melanoma patients; however, the efficacy of completing lymph node dissection remains questionable. The aim of our study was to assess the correlation between known prognostic factors, mutational occurrence of BRAF and NRAS in the primary tumor, and SLN status. Statistical analysis revealed that Breslow thickness was associated with SLN status; however, neither NRAS nor BRAF showed a predictive value. Furthermore, NRAS mutation in primary tumors proved to be an independent factor of tumor progression. This suggests that regardless of the SLN status, the NRAS-mutant subgroup of patients requires closer monitoring. ABSTRACT: Purpose: To assess the prognostic role of sentinel lymph node status (SLN) in melanoma patients, a statistical comparison was performed with the application of already known prognostic factors, mutational occurrence of BRAF and NRAS in the primary tumor, as well as disease outcome. Methods: Our retrospective single-center study involved 159 melanoma cases, who underwent SLN biopsy. The following clinico-pathological data were collected: age, gender, location of primary tumor, Breslow thickness, ulceration degree, histological subtype, mitosis count, lymphovascular and perineural invasion, presence of tumor-infiltrating lymphocytes, regression signs, mutations of BRAF and NRAS of the primary tumors, and SLN status. Results: From the studied clinico-pathological factors, only Breslow thickness increased the risk of SLN positivity (p = 0.025) by multivariate analysis, while neither BRAF nor NRAS mutation of the primary tumor proved to be a predictor of the SLN status. While the NRAS-mutant subgroup showed the most unfavorable outcome for progression-free and distant metastasis-free survival, their rate of positive SLNs proved to be relatively lower than that of patient groups with BRAF mutation and double-wild-type phenotypes. Conclusion: Similarly to the importance of SLN positivity, NRAS mutation of the primary tumor proved to be an independent prognostic factor of progression. Therefore, despite negative SLN, this NRAS-mutant subgroup of patients still requires closer monitoring to detect disease progression.