Sentinel lymph node biopsy in patients with clinical stage IIB/C cutaneous melanoma: A national cohort study.

ABSTRACT

BACKGROUND: Approval of adjuvant anti-programmed cell death protein 1 therapy for pathologic stage IIB/C cutaneous melanoma has led some to question the role of sentinel lymph node (SLN) biopsy in the clinical stage IIB/C disease. OBJECTIVE: To determine the prognostic significance of SLN staging on disease-specific survival (DSS) for clinical stage IIB/C primary cutaneous melanoma in the preimmunotherapy era. METHODS: A retrospective cohort study was performed evaluating patients who underwent excision of clinical stage IIB/C cutaneous melanoma using the Surveillance, Epidemiology, and End Results database (2004-2011). Patients who did and did not undergo SLN biopsy were compared using propensity matching, and among those who underwent SLN biopsy, matched patients were further stratified by SLN status (SLN positive [SLN+] or SLN negative [SLN-]). RESULTS: Of the 8562 patients evaluated, 6021 (70.3%) underwent SLN biopsy. SLN positivity was associated with significantly reduced 5-year DSS among matched patients who underwent SLN biopsy (47.1% SLN+ vs 75.5% SLN-; P < .001). Five-year DSS remained significantly different across matched T-stages T3b (54.2% SLN+ vs 64.8% SLN-; P = .004), T4a (55.5% SLN+ vs 71.6% SLN-; P = .001), and T4b (38.6% SLN+ vs 60.9% SLN-; P < .001). LIMITATIONS: Retrospective study. CONCLUSION: For patients with clinical stage IIB/C cutaneous melanoma, SLN status provides essential prognostic information.