Sentinel Lymph Node Biopsy for Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (cSCC) often presents localized in the skin, but when it metastasizes to regional lymph nodes prognosis declines. Despite this, the role of sentinel lymph node biopsy (SLNB) in detecting metastasis is not well defined. This study uses the National Cancer Database (NCDB) to evaluate the role of SLNB in cSCC.

Patients with cSCC who underwent complete surgical excision (CSE) alone or CSE + SLNB were selected from the NCDB from 2012 to 2020. Overall survival (OS) in these cohorts was compared. Subgroup analyses of SLNB status and addition of completion lymph node dissection (CLND) were performed. Adjusted hazard ratio (HR) and 95% CI were calculated.

Of 2,730 patients, 42.3% underwent SLNB, and 15.4% had positive SLNB. Univariate survival analysis showed better OS in CSE + SLNB vs CSE alone (HR 0.85, 95% CI 0.74 to 0.98, p = 0.0253), and worse OS in SLNB-positive vs -negative patients (HR 2.82, 95% CI 2.22 to 3.58, p < 0.0001). In an adjusted survival model, better OS was associated with CSE + SLNB vs CSE alone (HR 0.70, 95% CI 0.59 to 0.82, p < 0.001), worse OS was associated with male sex, comorbid conditions, T2 or higher tumor, and lymphovascular invasion. Subgroup analysis of SLNB-positive patients showed no OS benefit with CLND (HR 0.63, 95% CI 0.30 to 1.33, p = 0.221).

An OS benefit was seen in patients who underwent SLNB, but not CLND. Although this may reflect a selection bias of the study population, given that a positive SLNB was associated with worse OS and new trials show survival benefit with the use of adjuvant therapies, future studies are needed to define the role of SLNB in patients with cSCC.