Prognostic Value of Sentinel Lymph Node Biopsy Compared with that of Breslow Thickness: Implications for Informed Consent in Patients with Invasive Melanoma

BackgroundSentinel lymph node (SLN) status is reportedly a powerful prognosticator of survival. Breslow thickness alone provides significant prognostic information. ObjectiveTo assess overall survival (OS) according to tumor depth based on SLN status. Materials and MethodsMEDLINE, EMBASE, and the Cochrane Central Database were searched for studies. Included studies evaluated overall survival according to SLNB results and were stratified according to Breslow thickness. Meta-analysis was performed if appropriate in each category for which three or more studies reported risk estimates and variability measurement. ResultsTwenty-nine articles met inclusion criteria. Six met the criteria for meta-analysis. In individuals with thin melanoma (<1mm), SLN-negative status conferred no survival advantage (sign test, p>.99). Few studies were available for intermediate depths, and most reported worse survival in SLN-positive patients, although the difference was not statistically significant (p>.05). For thick melanoma (>4mm), SLN positivity was related to worse prognosis (sign test, p=.004). Based on the pooled results of six studies of patients with tumors 4mm thick or thicker, SLN-positive patients had a greater likelihood of dying (hazard ratio=2.42, 95% confidence interval=2.00-2.92). ConclusionsSentinel lymph node biopsy may not provide more-accurate prognostic information than Breslow thickness for most melanomas.