National Practice Patterns in the Management of the Regional Lymph Node Basin After Positive Sentinel Lymph Node Biopsy for Cutaneous Melanoma

Background Immediate completion lymph node dissection (CLND) for patients with sentinel lymph node (SLN) metastasis from cutaneous melanoma has been replaced largely by ultrasound nodal surveillance since the publication of two landmark trials in 2016 and 2017. National practice patterns of CLND remain poorly characterized. Methods Patients with a diagnosis of cutaneous melanoma in 2016 and 2018 without clinical nodal disease who underwent sentinel lymph node biopsy (SLNB) were identified from the National Cancer Database (NCDB). Characteristics associated with CLND were analyzed by uni- and multivariate logistic regression. Overall survival (OS) was estimated using Kaplan-Meier and Cox proportional hazards regression analyses. Results Of the 3517 patients included in the study, 1405 had disease diagnosed in 2016. The patients with cutaneous melanoma diagnosed in 2016 had a median age of 60 years and a tumor thickness of 2.3 mm compared to 62 years and 2.4 mm, respectively, for the patients with cutaneous melanoma diagnosed in 2018. According to the NCDB, 40 % ( n = 559) of the patients underwent CLND in 2016 compared with 6 % ( n = 132) in 2018. The factors associated with receipt of CLND in 2018 included younger age (odds ratio [OR], 0.97; 95 % confidence interval [CI], 0.95–0.99; p = 0.001), rural residence (OR, 3.96; 95 % CI, 1.50–10.49; p = 0.006), head/neck tumor location (OR, 1.88; 95 % CI, 1.10–3.23; p = 0.021), and more than one positive SLN (OR, 1.80; 95 % CI, 1.17–2.76; p = 0.007). The 5-year OS did not differ between the patients who received SLNB only and those who underwent CLND (hazard ratio [HR], 0.93; p = 0.54). Conclusion The rates of CLND have decreased nationally. However, patients with head/neck primary tumors who live in rural locations are more likely to undergo CLND, highlighting populations for which treatment may be non-uniform with national practice patterns.