Recurrence Patterns and Prognostic Factors in Sentinel Lymph Node-Negative Melanoma in a Taiwanese Cohort With Predominant Acral Melanoma.

Cutaneous melanoma in Asian populations is characterized by a predominance of acral melanoma and distinct clinicopathologic features. Although sentinel lymph node biopsy (SLNB) is widely used for staging, a subset of SLN-negative patients still develop recurrence, and evidence regarding recurrence patterns and prognostic factors in this group remains limited, particularly in acral-predominant cohorts. We conducted a retrospective cohort study of consecutive patients with cutaneous melanoma evaluated at Taipei Veterans General Hospital between 2005 and 2025. A total of 181 patients were included and categorized into SLN-positive (n = 89) and SLN-negative (n = 92) groups for survival analysis, with further analyses of recurrence patterns and prognostic factors restricted to the SLN-negative cohort. Kaplan-Meier analysis showed significantly poorer recurrence-free survival (RFS) and overall survival (OS) in the SLN-positive group compared with the SLN-negative group (both p < 0.001). Among SLN-negative patients (mean age, 72.3 years; 88.0% acral melanoma), 25.0% developed recurrence during a median follow-up of 28.5 months, corresponding to a 5-year recurrence rate of 30.9%. Nodal recurrence was the most frequent initial pattern and tended to occur earlier than other types of recurrence. Multivariable analysis identified lower body mass index, diabetes mellitus, and ulceration as factors associated with poorer RFS, while older age, lower body mass index, and greater Breslow thickness were associated with poorer OS. These findings suggest that recurrence remains a clinically relevant concern in SLN-negative melanoma in acral-predominant Asian populations. Careful follow-up may be warranted, particularly in patients with unfavorable clinicopathologic features.