Complete lymph node dissection in cutaneous melanoma patients with positive sentinel lymph node: Outcome and predictors in a retrospective cohort study over 16 years.

Background: In melanoma treatment, complete lymph node dissection (CLND) has been considered the therapeutic gold standard in patients with positive sentinel lymph node biopsy (SLNB). This long-held approach was revised in 2017, with recent evidence questioning the therapeutic benefit of CLND in malignant melanoma (MM) therapy. In this study, we aimed to fill this knowledge gap by retrospectively analyzing the impact of CLND on MM patients' survival.

Methods: We retrospectively analyzed the multi-center population-based Clinical Cancer Registry at the Tumor Center Regensburg (TUDOK) database (2004-2020) to identify patients who had been diagnosed with SLN-positive MM and underwent (non)invasive management thereof. Patient cohorts were subdivided according to the treatment received (CLND and waiving CLND). Primary outcomes included overall survival (OS), recurrence-free survival (RFS), and cumulative recurrence rate.

Results: We identified 1143 MM patients, of whom 126 (11.0%) had positive SLN status. CLND was waived in the majority of SLN-positive MM cases (n = 71; 56.3%), with 55 (43.7%) patients undergoing CLND. Univariable and multivariable Cox regression revealed no significant advantage for CLND patients compared to non-CLND patients in OS (HR=0.970, p = 0.915 and HR=1.295, p = 0.479, respectively), RFS (HR=1.050, p = 0.849 and HR=1.220, p = 0.544, respectively), and cumulative recurrence rate (HR=1.234, p = 0.441 and HR=1.220, p = 0.544), respectively).

Conclusion: We found that CLND had no significant impact on patient survival and MM recurrence rate, thus corroborating the validity of current clinical guidelines.