Assessing the sentinel lymph node remains a cornerstone of melanoma staging. However, ~80% of sentinel lymph node biopsies (SLNB) are negative and nontherapeutic and unnecessarily expose the patients to surgery‐related complications. 

A recent study gauged the potential of the Merlin assay to reduce SLNB‐associated complications. The Merlin assay employs clinicopathologic variables and tumor gene expression profiling to determine low‐risk patients who may refrain from SLNB.

The study utilized the Merlin test development cohort to determine SLNB complication rates for procedures performed between 2004 and 2018 at Mayo Clinic. It evaluated complications like lymphedema, seroma, infection/cellulitis, hematoma, and wound dehiscence. The study excluded the patients undergoing a completion lymph node dissection.

The findings were as follows:

• The study included 558 patients.
• It found the overall 90‐day complication rate specific to SLNB (1 year for lymphedema) to be 17.4%.
• The most common complications observed were seroma (9.3%), infection/cellulitis (4.8%) and lymphedema (4.3%).
• These complications mainly were in patients with a lower extremity primary tumor location versus other locations.
• Application of the Merlin test would have decreased the SLNB‐related complications by 59%.

Thus, SLNB is a safe procedure but with a significant complication rate. Merlin testing might lessen the need for SLNB and its associated complications.

Source: Hieken TJ, Sadurní MB, Quattrocchi E, et al. Using the Merlin assay for reducing sentinel lymph node biopsy complications in melanoma: a retrospective cohort study. Int J Dermatol. 2022;61(7):848-54.