Secondary sentinel node biopsy after previous excision of the primary tumor in squamous cell carcinoma of the vulva.

Background: To reduce morbidity of radical groin dissection, the sentinel-node (SLN) procedure was implemented for the treatment of vulvar cancer. It has been proven to be a safe alternative in early-stage disease. Feasibility and safety of the procedure after previous vulvar surgery remain unclear.

Methods: A total of 106 patients with primary vulvar cancer undergoing the SLN procedure were analyzed. Seventy-four patients received the SLN procedure concomitant to vulvar surgery [primary-sentinel group (PSG)], whereas 32 patients had vulvar surgery before secondary SLN [secondary-sentinel group (SSG)].

Results: SLN detection was possible in all patients. Three (9.4 %) patients in the SSG and 30 (40.5 %) in the PSG had metastatic spread to the SLN and underwent radical groin dissection. Median interval between vulva surgery and secondary sentinel was 34 days (range, 7-98). In the SSG tumor, stages were earlier with smaller tumor size (median 19 mm in the PSG vs. 9 mm in the SSG) and lesser invasion depth (4 vs. 2 mm; p < 0.001). There were no groin recurrences in the SSG and 5.4 % in the PSG. No significant difference regarding disease-free survival (DFS) could be detected (3-year DFS of 72.5 % in the PSG compared with 92.5 % in the SSG (median DFS not reached, p = 0.114)). Adjusting for potential confounders (tumor stage, nodal status, tumor size, invasion depth) did not alter the results with regards to DFS.

Conclusions: Our results suggest that a secondary SLN procedure after previous vulvar surgery is feasible and can accurately reflect the groin status of selected patients. Ideally, prospective trials should be conducted to verify accuracy and oncologic safety of the procedure.