Abstract
BACKGROUND: Sentinel lymph node biopsy (SLNB) is often omitted in selected patients with advanced primary melanoma, although the justification/criteria for omission have been debated. OBJECTIVE: We sought to determine whether assessment of frailty could serve as an objective marker to guide selection for SLNB in patients with advanced primary melanoma. METHODS: Patients presenting with clinical stage IIC (ulcerated, > 4 mm Breslow thickness) cutaneous melanoma from January 1999 through June 2019 were included. Frailty was assessed using the Memorial Sloan Kettering Frailty Index (MSK FI), a composite score of functional status and medical comorbidities. Five-year melanoma-specific survival (MSS) and overall survival (OS) were estimated using Cox regression, and predictors of OS were identified using competing risk models. RESULTS: MSS did not differ between patients who did (n = 451) or did not undergo SLNB (n = 179) [63.2% vs. 65.0%, p = 0.14]; however, omission of SLNB was associated with decreased 5-year OS (29% vs. 44%, p < 0.001). In a multivariable competing risk model, selection for SLNB omission was an independent predictor of death from non-melanoma causes (hazard ratio [HR] 1.7, 95% confidence interval [CI] 1.2-2.3, p < 0.001). After incorporation of the MSK FI score into the multivariable model in this subset, MSK FI (HR 2.4, 95% CI 1.5-4.1, p < 0.001), but not SLNB omission, was an independent predictor of poorer OS. CONCLUSION: We observed worse OS in patients with thick melanoma selected not to undergo SLNB, which was attributed to death due to non-melanoma causes. Formal assessment of frailty may provide an objective prognostic measure to guide selective use of SLNB in these patients.