Outcome After Sentinel Lymph Node Dissection in Vulvar Cancer: A Subgroup Analysis of the AGO-CaRE-1 Study

Analyzing the large patient cohort of the multicenter AGO-CaRE-1 study, we compared isolated sentinel lymph node dissection (SLND) with radical lymph node dissection (LND) of the groin in relation to recurrence rates and survival. The AGO-CaRE-1 study retrospectively collected data on treatment patterns and follow-up of vulvar cancer patients [International Federation of Gynecology and Obstetrics (FIGO) stage 1B] treated at 29 gynecologic cancer centers between 1998 and 2008. This subgroup analysis evaluated the influence of SLND alone on progression-free survival (PFS) and overall survival (OS). In 487 (63.1%) of 772 included patients with tumors smaller than 4 cm, an LND was performed and no metastatic lymph nodes were detected (LN0). Another 69/772 (8.9%) women underwent SLND alone, showing a negative SLN (SLN0). Tumors in the LN0 group were larger and showed a deeper invasion (LN0 vs. SLN0 tumor diameter: 20.0 vs. 13.0 mm, p < 0.001; depth of invasion: 4.0 vs. 3.0 mm, p = 0.002). After a median follow-up of 33 months (0-156), no significant differences in relation to isolated groin recurrence rates (SLN0 3.0% vs. LN0 3.4%, p = 0.845) were detected. Similarly, univariate 3-year PFS analysis showed no significant differences between both groups (SLN0 82.7% vs. LN0 77.6%, p = 0.230). A multivariate Cox regression analysis, including tumor diameter, depth of invasion, age, grading, and lymphovascular space invasion was performed: PFS [hazard ratio (HR) 0.970, 95% confidence interval (CI) 0.517-1.821] and OS (HR 0.695, 95% CI 0.261-1.849) did not differ significantly between both cohorts. This subgroup analysis of the large AGO-CaRE-1 study showed similar results for groin LND and SLND alone with regard to recurrence rates and survival in node-negative patients with tumors < 4 cm.