Comparison of Outcome after Sentinel Lymph Node Biopsy or Inguinal Lymph Node Dissection in Patients with Nodal Negative Squamous Vulvar Cancer

Abstract

Sentinel lymph node biopsy (SLNB) can reduce postoperative morbidity in women with vulvar cancer but data on long-term outcome of SLNB compared to inguinal lymph node dissection (ILND) is rare. Recurrence rates, disease-free survival (DFS) and overall survival (OS) from pT1/T2 pN0 squamous vulvar cancer from 1992 -2011 were retrospectively compared between patients with SLNB (n=56) or ILND (n=56). PT2 tumors (59% vs. 11%; p<0.001) and complete vulvectomy (39% vs. 4%; p < 0.001) occured more often in the ILND than the SLNB group with no difference in lymph node recurrence rate. Multivariate survival analysis considering the year of primary diagnosis, tumor stage and surgery revealed no significant effect of treatment on DFS (p=0.062) or OS (p=0.924). SLNB seems to be a safe treatment for women with pT1/T2 nodal-negative vulvar cancer with no difference in DFS or OS compared to ILND. Those results confirm the results of the GROINSS-V Study and other literature with the longest follow-up data reported within a real-life collective. Impact statementSLNB has been shown to reduce postoperative morbidity in women with vulvar cancer, however, data on long-term outcome of SLNB in vulvar cancer is rare. The aim of this study was to evaluate the outcome of patients with nodal-negative vulvar cancer that had undergone either SLNB or ILND in a clinical collective. Patients in the ILND group presented with more pT2 tumors (59% vs. 11%; p< 0.001) and followed by complete vulvectomy (39% vs. 4%; p <0.001). The lymph node recurrence rate was not significantly different between both groups (p=0.57). A multivariate survival analysis accounting for year of primary diagnosis, tumor stage and type of surgery revealed no significant effect of treatment on DFS or OS. SLNB seems to be a safe treatment for women with T1/T2 nodal-negative vulvar cancer, as we observed no difference in DFS or OS compared to patients with ILND. However, because of the observed bias between the two groups, results have to be interpreted carefully and need to be confirmed in larger prospective trials. Nevertheless, the results represent further data regarding the oncological safety of SNB supporting current literature and strongly underlie its value in the described setting with the longest follow-up, to date, reported.