Fellow, Complex General Surgical Oncology Saint John's Cancer Institute Santa Monica, California, United States
Disclosure: Disclosure information not submitted.
Participants should be aware of the following financial/non-financial relationships:
Jessica Weiss, MD: Disclosure information not submitted.
Introduction: There remains significant variability in practice regarding the management of patients with thick melanoma (≥4mm) with clinically node negative (cN0) disease. The current study evaluates factors that influence overall survival (OS) in patients with thick melanoma.
Methods: All patients between ages 18-75 diagnosed with cN0, non-metastatic, thick (≥4mm, T4) melanoma between 2012-2017 were identified in the National Cancer Database. Patients were stratified into three groups: no nodal evaluation, sentinel node biopsy (SLNB), and complete lymphadenectomy without SLNB (CLD). OS was compared using Kaplan-Meier analyses and Cox proportional hazard regression. Further analysis was performed to determine the impact of SLNB result on OS.
Results: Of 7,299 patients, 1,303 (18%) had no nodal evaluation performed, 4,586 (63%) had a SLNB, and 1,410 (19%) had an upfront CLD. Evaluation of the nodal basin with either SLNB (HR 0.56; 95%CI 0.42-0.71) or CLD (HR 0.60; 95%CI 0.45-0.81) was associated with improved OS compared to no nodal evaluation even after controlling for other factors. 5-year OS in patients without nodal evaluation was 47.6% (95%CI 43.9-51.7) compared to 67% (95%CI 65-69) with SLNB and 60.4% (95%CI 56.8-64.3) with upfront CLD. Among patients undergoing SLNB, a tumor positive sentinel node (+SLN) was identified in 25% of patients. 5-year OS was lower for +SLN compared with -SLN (52.1%; 95%CI 47.7-56.9 vs 71.7%; 95%CI 69.5-74). Among patients with a +SLN, a completion lymphadenectomy was performed in 648 (56.3%) but was not associated with improved survival (HR 0.932, p = 0.59) when compared to observation alone. Increasing depth of invasion was associated worse OS (HR 1.052, CI 1.03-1.08, p < .001). Other factors associated with decreased OS were older age, high Charlson score, and ulcerated primary lesion (p< 0.001).
Conclusions: There is extensive practice variation in the management of cN0 patients with thick melanoma. This study suggests that the depth of invasion and nodal assessment provide important prognostic information regarding OS for these patients. Patients with thick melanoma should have nodal staging with SLNB and do not appear to benefit from a CLD in the setting of a +SLN.
Learning Objectives:
Describe current surgical techniques used in the management of thick melanoma.
Identify factors associated with improved survival in patients with thick melanoma.
Describe the role of lymph node basin evaluation in the management of thick melanoma.
