Background: The value of sentinel lymph node (SLN) surgery for patients with clinically node-negative T1b through T3 cutaneous melanomas is well-established. However, further precision in selecting patients for SLN surgery would be desirable as ∼80% of these patients have a negative SLN and might be spared complications potentially attributable to the addition of SLN surgery to wide local excision. Objective: The Merlin assay uses clinicopathologic variables and tumor gene expression profiling to identify low-risk patients who might avoid SLN surgery. Our aim was to assess the potential impact of this approach to patient triage on reducing postoperative complications. Methods: We utilized the Merlin test development cohort to determine complication rates for SLN procedures performed between 2004 and 2018 across Mayo Clinic tertiary care sites. Complications evaluated were lymphedema, seroma, infection/cellulitis, hematoma, and wound dehiscence. Patients who proceeded to completion lymph node dissection were excluded. Results: 558 patients, median age 64.2 years, were included. The anatomic site of the primary tumor was head/neck in 144 (25.8%), trunk in 179 (32.1%), upper extremity in 147 (26.3%), lower extremity in 88 (15.8%). The overall 90-day complication rate attributed to SLN surgery was 17.4%. The most common complications were seroma (9.3%), infection/cellulitis (4.8%), and lymphedema (4.3% at one year). Complications were more common in patients with a lower extremity primary tumor location versus other locations. 51% of melanomas had a low-risk Merlin test result; SLNb reduction rates were similar in patients with and without surgery-related complications. Avoiding SLNb by Merlin testing lowers complication rates to a similar extent for all registered complications, specifically seroma by 68.8% and lymphedema by 58.1%. Moreover, post-procedure emergency department visits were reduced by 100%. Limitations: Retrospective data collection. Conclusion: SLN surgery is a safe procedure but carries a significant complication rate. Merlin testing might decrease the need for SLN surgery and the number of its associated complications.
QIM22-194 Figure 1. SLNb complications
Citation: Journal of the National Comprehensive Cancer Network 20, 3.5; 10.6004/jnccn.2021.7223
