Sentinel lymph nodes in vulvar cancer: Management dilemmas in patients with positive nodes and larger tumors

Background Although sentinel lymph node (SLN) biopsy has been routinely used in the treatment of invasive squamous cell carcinoma (SCC), questions still remain regarding the management of patients with positive nodes, as well as its use in patients with larger tumors. Methods Retrospective study of all patients at a single institution with primary vulvar cancer who had SLN biopsy (2008–2015). Patient and tumor characteristics were collected from hospital records. For patients with positive SLN and for those with tumors ≥40 mm, recurrence rates and location were specifically recorded. Results SLN biopsy was successful in 159 patients (245 groins). Median follow-up was 31 months. 120 patients (187 groins) had a negative SLN without an inguinofemoral lymph node dissection (IFL); there were 6 ipsilateral groin recurrences (5%). 7 patients had micrometastasis (≤2 mm) in the SLN and were treated by radiotherapy. There were no recurrences in the irradiated groins. 19 patients with a positive unilateral SLN had bilateral IFL. One (5.3%) had a positive node in the contralateral groin. 9 patients with positive unilateral SLN had subsequent ipsilateral IFL; there were no groin recurrences in the contralateral groin. 20 patients had tumor size ≥40 mm. 11 patients had a negative SLN biopsy, and thus no IFL; of these patients, 1 had an isolated groin recurrence (9%). Conclusion These data suggest it is reasonable to omit a full groin dissection for micrometastatic disease in the SLN, and to perform a unilateral groin dissection in patients with unilateral SLN metastasis. SLN alone in larger tumors may have a higher groin recurrence rate.