P43. Does Sentinel Node Biopsy Reduce the Risk of Death from Melanoma? A Systematic Review and Meta-analysis.

Introduction:  Whether sentinel node biopsy (SNB) for melanoma results in a survival benefit has been controversial. The MSLT-I randomized controlled trial (RCT) demonstrated a statistically non-significant trend towards a reduced risk of death from melanoma (hazard ratio (HR) 0.88) but was underpowered to provide a definitive answer. This systematic review and meta-analysis aimed to address this question.

Methods:  Medline, Embase, Cochrane CENTRAL, and the ClinicalTrials.gov website (to 8^th January 2025) were searched using terms for melanoma, SNB, and survival. Screening and data extraction were performed in duplicate. Selected studies reported survival outcomes for patients who underwent SNB and patients who did not. Studies that had undertaken multivariable adjusted analyses were included in a meta-analysis. Protocol registration: CRD4203494674.

Results:  Of 59 included studies from the systematic review, fourteen were included in the meta-analysis: one RCT and 13 multivariably-adjusted cohort studies (reporting 42,853 patients). The meta-analysis using a fixed effects model gave an HR of 0.88 (95% CI: 0.83-0.93, p< 0.00001) for risk of death from melanoma after SNB compared to no SNB, with low-moderate heterogeneity (I² = 0.26). Sensitivity analyses confirmed that this result was not dependent on any single study or the use of systemic therapy. Recurrence was reported in nine studies (reporting 11,625 patients); meta-analysis gave an HR of 0.71 (95% CI 0.66-0.76, p< 0.00001) with low heterogeneity (I² = 23%).

Conclusions:  This large meta-analysis of the best available data confirmed the HR of 0.88 found by the MSLT-I RCT, with adequate power to achieve statistical significance (p < 0.00001). This 12% relative reduction in risk of death from melanoma was also stable on sensitivity analyses, confirming its robustness. The results indicate a likely true survival benefit for patients undergoing SNB in addition to wide excision of their primary melanoma.