E303: Trends in Complete Lymph Node Dissection for Melanoma Patients Post-MSLT2 Trial: Insights from the Vizient Database

The MSLT2 trial found that patients with SLNB+ melanoma did not show improved disease-specific survival when undergoing complete lymph node dissection (CLND) compared to observation. However, since its publication, the nationwide adoption of these guidelines remains uncertain. This study evaluates CLND rates after MSLT2 and identifies factors influencing its application across different hospitals and demographics.

Methods:

Utilizing the Vizient database, we identified patients diagnosed with melanoma and SLNB+ from 2010-2022. The primary objective was to assess the rate of CLND after the introduction of the MSLT2 guidelines. The secondary objective was to analyze the relationship between patient demographics, hospital features, and the likelihood of undergoing CLND.

Results:

A total of 157,669 SLNB+ patients were identified comprising 60% males (N=93,826) and 40% females (N=63,843). Among these, 25% (N=40,076) proceeded with CLND. Following the introduction of MSLT2 in 2017, the rate of CLND significantly decreased from 73.8% to 24.1% (p< 0.001). When comparing patients who did and did not undergo CLND post MSLT2 implementation, significant differences were observed in certain demographic and institutional factors, such as ethnicity, insurance type, and hospital category (p< 0.05). Specifically, being of black ethnicity (AOR 1.82; CI 1.16-2.85; p=0.009), having Medicare (AOR 1.19; CI 1.05-1.35; p=0.007), having a higher Elixhauser Comorbidity Index (AOR 1.72; CI 1.59-1.87; p< 0.001) and being treated in an Academic Medical Center (AOR 1.6; CI 1.51-1.71; p< 0.001) emerged as independent predictors for undergoing CLND. Conversely, with each subsequent year, the likelihood of a patient undergoing CLND dropped by 20% (AOR 0.8; CI 0.79-0.81; p=0.009). Treatment at Community Hospitals (AOR 0.19; CI 0.16-0.21; p< 0.001) were identified as negative predictors.

Conclusions:

Following the implementation of MSLT2 in 2017, CLND rates among SLNB+ patients dropped significantly. Post-MSLT2, black ethnicity, having Medicare, a higher Elixhauser Comorbidity Index, and treatment in an Academic Medical Center increased the likelihood of undergoing CLND. However, with each passing year, the chance of a patient getting CLND decreased, and those treated at Community Hospitals were less likely to undergo the procedure.