Using the Merlin assay for reducing sentinel lymph node biopsy complications in melanoma: a retrospective cohort study

Abstract

Background The assessment of the sentinel lymph node is a cornerstone of melanoma staging. However, ~80% of sentinel lymph node biopsies (SLNB) are negative and nontherapeutic, and patients are unnecessarily exposed to surgery‐related complications. Here, we gauged the potential of the Merlin assay to reduce SLNB‐associated complications. The Merlin assay uses clinicopathologic variables and tumor gene expression profiling to identify low‐risk patients who may forgo SLNB. Methods We utilized the Merlin test development cohort to determine SLNB complication rates for procedures performed between 2004 and 2018 at Mayo Clinic. Complications evaluated were lymphedema, seroma, infection/cellulitis, hematoma, and wound dehiscence. Patients who underwent a completion lymph node dissection were excluded. Results A total of 558 patients were included. The overall 90‐day complication rate specific to SLNB (1 year for lymphedema) was 17.4%. The most common complications were seroma (9.3%), infection/cellulitis (4.8%), and lymphedema (4.3%). All three were more common in patients with a lower extremity primary tumor location versus other locations. With Merlin test results applied, SLNB‐related complications would have decreased by 59%. Conclusion SLNB is a safe procedure but carries a significant complication rate. Merlin testing might reduce the need for SLNB and its associated complications.

Cost evaluation of the Merlin assay for predicting melanoma sentinel lymph node biopsy metastasis

“…These standardized costs are then used for publication and comparison. Patients with complications were identified by cost data, which were validated by a previously published review of the electronic medical record 7 …”

“…This was consistent with a recent publication from Mayo Clinic, which tracked the following complications for T1 to T2 melanoma patients: lymphedema, seroma, infection, hematoma, and wound dehiscence. 7 In our base‐case analysis, we selected the Merlin test characteristics for individuals with T1b cancer. For this tumor stage, the test sensitivity and specificity were 52.9% and 75.6%, respectively, as assessed by previous research.…”

“…Patients with complications were identified by cost data, which were validated by a previously published review of the electronic medical record. 7 …”

“… 5 SLNB is a more complex and time‐consuming procedure than is often appreciated and requires sophisticated hospital infrastructure and medical specialists. 6 Moreover, all patients who undergo SLNB face a greater than 10% risk of short‐ and long‐term complications, including bleeding, infection, seroma, and lymphedema, 7 as well as an up to 5% risk of hospital readmission within 30 days because of postsurgical complications. 8 Therefore, better methods are needed to identify patients with early‐stage disease whose risk of nodal metastasis is so low that they can safely forgo SLNB.…”

Debating Sentinel Lymph Node Biopsy for Melanoma in the Modern Adjuvant Era

“…The false-negative rate for SLNB, which is defined as the proportion of node-positive patients who had a negative SLNB, has been reported to be >10%. [3][4][5][6] However, modern innovations including single-photon emission computed tomographycomputed tomography lymphoscintigraphy have improved the negative predictive value of SLNB to >95%. 7 Cutaneous melanoma most commonly presents without clinically apparent nodal metastases (stages I and II), as defined by the 8th edition of the American Joint Committee on Cancer melanoma staging system.…”