Patterns of Failure in Cutaneous Head and Neck Melanoma Following Negative Sentinel Lymph Node Biopsy: A Retrospective Cohort Study

BackgroundCutaneous head and neck melanoma (cHNM) has a high rate of false-negative sentinel lymph node biopsy (SLNB) and up to a 25% risk of recurrence despite negative SLNB. The aim of this study was to investigate the pattern of melanoma recurrence in patients with cHNM with negative SLNB.MethodsA retrospective cohort study of consecutive cHNM patients at a tertiary care centre from 2014-2022. We included all cHNM patients with negative SLNB. All patients were categorized into Breslow thickness >2 mm and ≤2 mm and extracted information pertaining to histopathological characteristics and the presence and type of disease recurrences. We performed multivariable analysis using logistic and cox regression. We used an alpha of 0.05 and all statistical analyses were performed using R software.ResultsOverall, 167 patients met eligibility criteria and of these, 53.5% patients had cHNM ≤2 mm thick and 46.7% had lesions >2 mm thick. The overall recurrence rate was 29.3%. Multivariable analysis demonstrated that Breslow thickness [aOR: 5.89 (95% CI: 1.37, 32.3), <i>P</i> = 0.02] was associated with distant recurrence. Multivariable cox regression also identified that pathological ulceration [aHR: 3.17 (95% CI: 1.61, 7.66), <i>P</i> = 0.01] predicted time to distant recurrence. The SLNB false omission rate was 3.6% (95% CI: 1.3%, 7.7%).ConclusionSLNB-negative cHNM patients with high-risk pathological features may benefit from adjuvant immunotherapy.