Utilization and outcomes of sentinel lymph node biopsy in patients with early stage vulvar cancer

Abstract

Objective: A retrospective cohort study comparing survival and perioperative outcomes of patients with early vulvar cancer who underwent sentinel lymph node biopsy versus standard lymphadenectomy METHODS: Patients diagnosed between January 2012 and December 2015 with vulvar squamous cell carcinoma of less than 4 cm in size, with invasion of at least 1 mm, who underwent sentinel lymph node biopsy, lymphadenectomy, or both were identified from the National Cancer Database. Overall survival was evaluated following generation of Kaplan-Meier curves and compared with the log-rank test for patients who had at least 1 month of follow-up. A Cox model was constructed to control for confounders.

Results: A total of 1583 patients were identified; 304 patients (19.2%) underwent sentinel lymph node biopsy alone. Sentinel lymph node biopsy utilization increased 13.9% between 2012 and 2015. Patients who underwent sentinel node biopsy alone were less likely to have comorbidities compared with those undergoing lymphadenectomy only or sentinel node biopsy with lymphadenectomy (25.3% vs 32.9% vs 31.9%, p=0.042), had smaller tumors (median 1.6 vs 2.0 vs 2.0 cm, p<0.001), and were less likely to have positive lymph nodes (11% vs 19.6% vs 28.1%, p<0.001). There was no difference in 3 year overall survival between the three groups (86.3% vs 82.1% vs 77.9%, p=0.26). After controlling for age, race, insurance, comorbidities, lymph node metastases, and tumor size, sentinel lymph node biopsy alone was not associated with worse overall survival compared with lymphadenectomy (HR 0.86, 95% CI 0.57 to 1.32). The sentinel node only group had shorter inpatient stays compared with lymphadenectomy only (median 1 vs 2 days, p<0.001) and a lower rate of unplanned readmission (1.7% vs 5.0%, p=0.010).

Conclusions: The utilization of sentinel lymph node biopsy is increasing in the management of vulvar cancer and is associated with superior perioperative outcomes without impacting overall survival.

Keywords: sentinel lymph node; vulvar neoplasms.