Sentinel lymph node status and oncological outcomes of high-risk and low-risk cutaneous primary melanoma

Introduction: Sentinel lymph node (SLN) status remains a key prognostic factor in melanoma. However, recent advances in immunotherapy have prompted debate over the necessity of Sentinel lymph node biopsy (SLNB). This study evaluates the impact of SLN on disease-free survival (DFS), recurrence, and staging in melanoma patients. Methods: A retrospective analysis was conducted on 300 patients with histologically confirmed cutaneous melanoma who underwent SLN biopsy between April 2018 and April 2023. Patients were classified as low-risk (T1–T3a) or high-risk (T3b–T4b). Clinical, pathological, and outcome data were analysed. Variables were compared using Mann-Whitney U test and Fisher’s exact test where appropriate. DFS and recurrence were evaluated relative to SLN status using Kaplan-Meier and log-rank test. Results: Median age was 60.7 years; 51.3% were female. SLN positivity was observed in 22% overall, significantly higher in high-risk patients (31.5% vs. 18.0%, P  = 0.009). Recurrence occurred in 16%, more frequently in high-risk patients (31.5% vs. 9.5%). Median DFS was 1389 days; lower in high-risk patients (1141 vs. 1481 days, P  < 0.001). SLN positivity correlated with reduced DFS (1168 vs. 1481 days, P  = 0.056). Breslow thickness and mitotic index predicted recurrence. SLNB led to major reclassification of clinical stage, identifying Stage IIIC disease in 31.46%. of cases presumed Stage IIB/C. Conclusion: SLNB provides essential prognostic and staging information. Its omission risks misclassification and mismanagement, impacting survival predictions and treatment decisions. SLNB should remain a cornerstone of staging especially in high-risk melanoma, even in the evolving context of immunotherapy.