Survival Impact of Immediate Complete Lymph Node Dissection for Chinese Acral and Cutaneous Melanoma with Micrometastasis in Sentinel Nodes: A Retrospective Study

Abstract Background Sentinel node biopsy (SNB) has become a critical part of standard surgical treatment for melanoma with no metastatic evidence. According to MSLT-II and DeCOG-SLT trials, for patients with positive sentinel nodes, immediate complete lymph node dissection (CLND) didn’t bring further benefit for patients’ survival. Argument remains among Chinese population with domination of acral subtypes whether CLND can be omitted. This study aims to investigate the impact of immediate CLND for SN positivity on relapse-free survival (RFS) in Chinese melanoma patients. Material and Methods Patients with acral or cutaneous melanoma of clinical stage I-II receiving SNB procedure and then detected with nodal micrometastasis were retrospectively identified at Fudan University Cancer Center (FUSCC) from January 2017 to December 2021. Clinicopathologic features and prognostic factors for RFS were analyzed. Results Among 381 patients who received SNB in the last five years, 130 (34%) cases with positive SN micrometastasis detected were identified in our study. 99 patients underwent immediate CLND while the other patients received observation alone. Among patients received CLND, the NSN positive rate was 22.2%. There were slightly less N1 stage in the CLND group compared to the non-CLND group, although the difference didn’t reach statistical significance (P = 0.075). There was no significant difference in RFS between the two groups (P = 0.184). Conclusions Immediate CLND didn’t bring further RFS benefit after an observation for Chinese melanoma with SN micrometastasis in real clinical practice, even for patients with acral subtype or more tumor burden such as thick Breslow invasion and ulceration.