Introduction/Background Since the introduction of the S2K AWMF guideline-based sentinel node biopsy technique in unifocal vulvar cancer (diameter of <4 cm) and unsuspicious groin lymph nodes, the morbidity rate of patients has significantly decreased in Germany. The groin recurrence rate after IFL is vary from 0% to 5.8%, in contrast to 2.3% (95% CI, 0.6% to 5%) in unifocal vulvar cancer vs 3% (95% CI, 1% to 6%) in multifocal vulvar cancer after SLNB only, as suggested in the GRoningen INternational Study on Sentinel node in Vulvar cancer (GROINSS-V-I) in 2008. Current guidelines suggest that in cases of metastasis of unilateral sentinel lymph node (SLN) biopsy (B), groin node dissection, namely inguinofemoral lymphadenectomy (IFL), should be performed bilaterally. However, a publication by Woelber et al. in Germany and and Nica et al. in Canada contradicted the current guideline indication for bilateral IFL in case of unilateral SLNB metastasis.

Methodology Our research study consisted of a single-center analysis from the Department of Obstetrics and Gynecology in the University Hospital of Dusseldorf, evaluating vulvar cancer patients treated with SLNB retrospectively from 2002 to 2018.

Results

1. Twelve women (n=12/30; 40%) had ipsilateral IFL only, in accordance with patient desire to avoid morbidity and/or old age. Only one woman was diagnosed having positive metastatic IFL and 11 women were negative IFL

2. Eighteen women (n=18/30; 60%) who received complete bilateral IFL were further divided into three subgroups:

   1. Thirteen women (n=13/30; 43.4%) had negative IFL results in both groins.

   2. One woman (n=1/30; 3.3%) had ipsilateral IFL metastasis.

   3. Four women (n=4/30; 13.3%) had contralateral IFL groin metastasis after unilateral SLNB metastasis initially.

Conclusion The depth of tumor cells infiltration is a significant factor in the prediction of contralateral metastasis (p=0.0038). According to our study results, radical bilateral IFL should be offered in treatment management of early primary vulvar cancer with anterior midline lesion and unilateral SLNB metastasis. However, the need for radical bilateral IFL in cases of lateralized tumor with positive ipsilateral SLNB should be further evaluated.

Disclosures The authors declare that there is no conflict of interest regarding the publication of this article. None of the authors received any funding for this study. This study is purely for scientific use and aimed to provide suggestions for current clinical guidelines and future research.