Lymph node count at inguinofemoral lymphadenectomy and groin recurrences in vulvar cancer.

OBJECTIVE The objective of the study is to determine the risk factors for groin recurrence (GR) in patients with primary vulvar squamous cell carcinoma (SCC) after inguinofemoral lymphadenectomy (IFL) without lymph node metastases and/or adjuvant chemoradiotherapy. METHODS The study is a multicenter retrospective review of clinical and histopathological data of patients with lymph node-negative vulvar SCC who underwent an IFL. Patients with and without GRs were compared to identify risk factors. RESULTS In 134 patients, 252 groins were eligible for the analyses--16 patients underwent ipsilateral IFL and 118 patients underwent bilateral IFL. Groin recurrences occurred in 4 (1.6%) of the 252 dissected groins. Besides, 1 patient who underwent ipsilateral IFL had a recurrence in the nonoperated contralateral groin; this groin was left out of analysis. The median number of dissected nodes per groin was 9.8 (range, 1-38) in all patients and 6.5 (range, 5-8) in patients with GR. Multivariate analyses showed that GR was related to poor differentiation (P = 0.04), and node count less than 9 (P = 0.04), no association with age, tumor localization, tumor diameter, focality, invasion depth, or stage was found. Nineteen patients with both low node count and poor differentiation had 19% GRs. Survival analyses showed less favorable survival in patients with poor differentiation. CONCLUSIONS The overall risk of developing GR after negative IFL in patients with vulvar SCC is low (1.6% per groin) but significantly higher in patients with tumors with a poor differentiation and lymph node count less than 9 at IFL. A large well-designed prospective study is needed to evaluate closer surveillance in patients at risk.