Long term outcomes in patients with sentinel lymph nodes (SLNs) identified by injecting remaining scar after previously excised vulvar cancer

Abstract

BackgroundLymph node metastasis is the most important prognostic factor in patients with vulvar squamous cell carcinoma (SCC). Previous excision of the vulvar tumor may disrupt lymphatic channels and alter the accuracy of the sentinel lymph node (SLN) biopsy. The purpose of this study was to measure outcomes after SLN biopsy in patients with and without previous excision of the vulvar tumor. MethodsRetrospective study of patients at a single institution with primary vulvar cancer, clinically negative nodes, and vulvar tumors < 4 cm treated with surgical excision who had SLN biopsy (2008–2015). ResultsThere were 106 cases of concomitant wide local excision (WLE) and SLN biopsy and 24 additional cases of patients who had previous vulvar surgery and no visible tumor; these patients underwent scar re-excision and SLN biopsy. Median follow-up was 31 months. Patients who had previous tumor excision were more likely to be of younger age (p = 0.0001), have a smaller tumor (p = 0.002), and less depth of invasion (p = 0.02). In the wide local excision of the scar specimen, 11 patients (46%) had no residual disease left, 8 patients (33%) had only vulvar intraepithelial neoplasia (VINIII), 4 patients (17%) had carcinoma in situ with focal invasion and 1 patient (4%) had invasive carcinoma within the second specimen, resected with clear margins.There were no groin recurrences in patients who underwent scar re-excision and who had a negative SLN biopsy. ConclusionSLN biopsy is feasible and safe in patients who have had previous excision of the vulvar tumor and present with a scar. When a SLN is detected by injecting the remaining scar, this accurately reflects the nodal status and does not negatively impact oncologic outcomes.