Objective: This study aimed to evaluate the recurrence rates after sole sentinel dissection in vulvar cancer and describe characteristics of groin recurrences.
Methods: All vulvar cancer cases between 2008 and 2014 were reviewed. Inclusion criteria were restricted to lymph node-negative patients, sole sentinel lymph node dissection (SLND), and tumor diameter less than 4 cm. In all patients, Tc-99m nanocolloid was used for preoperative SLN imaging. Regularly, planar lymphoscintigraphy and single-photon emission computed tomography with computed tomography were performed. Ultrastaging was routinely conducted on all negative lymph nodes.
Results: Of 140 vulvar cancer cases, 30 node-negative patients underwent sole SLND and met inclusion criteria. Keratinizing squamous cell carcinoma was determined in final histology in 20/30 (66.7%) patients and the mainly diagnosed tumor stage was pT1b (21/30, 70%). Three perioperative complications occurred. On average, 4.6 (1-9) SLNs were dissected per patient and 2.5 (1-6) per each groin, respectively. During a median follow-up of 43.5 (4-75) months, 5/30 (16.7%; 95% confidence interval, 7.3%-33.6%) local recurrences occurred. In addition, 2/30 (6.6%; 95% confidence interval, 1.9%-21.3%) groin recurrences were identified within a period of 12 months after the primary surgery. Both patients had large (>2 cm) midline tumors. Despite surgical as well as adjuvant treatment of the recurrent disease, both patients with groin recurrences died.
Conclusions: Sentinel lymph node dissection is a safe and feasible alternative in early vulvar cancer. But false-negative sentinel carry a high risk of mostly fatal groin recurrences. Especially, midline tumors larger than 2 cm have to be treated with caution, because they are mostly found in cases with groin recurrences after sole SLND.