Impact of the time interval between primary melanoma excision and sentinel node biopsy: A systematic review and meta-analysis

Background: Obtaining a sentinel lymph node biopsy (SLNB) specimen is a standard staging procedure in the management of cutaneous melanoma. However, there is no consensus on the safe time interval between the primary melanoma biopsy procedure and the SLNB procedure. Objective: We evaluated the association between time from biopsy to SLNB and patients' outcomes for melanoma. Methods: We performed this systematic review and meta-analysis based on the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results: Six retrospective studies were included. Nine thousand seven hundred five patients were identified, of which 4383 underwent a SNLB procedure at a time interval defined as early and 4574 at an interval defined as late. A combined hazard ratio of 1.25 (95% confidence interval [CI] 0.92-1.68) was determined, and there was high heterogeneity (I-2 = 83%; P=.002) of the SLNB time interval on melanoma-specific survival. The combined HR for disease-free survival was 1.05 (95% CI 0.95-1.15), with low heterogeneity (I-2 = 9%; P=.36). Regarding overall survival, a combined HR of 1.25 (95% CI 0.92-1.70) was found, with low heterogeneity (I-2 = 37%; P=.2). Limitations: There is heterogeneity between some studies. Conclusion: There are no significant differences in patient outcome between a short interval versus a long interval between the primary biopsy procedure and obtaining a SNLB specimen.