The need for pelvic treatment in patients with node-positive vulvar cancer (VSCC) and the value of pelvic lymphadenectomy (LAE) as a staging procedure to plan adjuvant radiotherapy (RT) is controversial. In this retrospective, multicenter analysis, 306 patients with primary node-positive VSCC treated at 33 gynecologic oncology centers in Germany between 2017 and 2019 were analyzed. All patients received surgical staging of the groins; nodal status was as follows: 23.9% (73/306) pN1a, 23.5% (72/306) pN1b, 20.4% (62/306) pN2a/b, and 31.9% (97/306) pN2c/pN3. A total of 35.6% (109/306) received pelvic LAE; pelvic nodal involvement was observed in 18.5%. None of the patients with nodal status pN1a or pN1b and pelvic LAE showed pelvic nodal involvement. Taking only patients with nodal status ≥pN2a into account, the rate of pelvic involvement was 25%. In total, adjuvant RT was applied in 64.4% (197/306). Only half of the pelvic node-positive (N+) patients received adjuvant RT to the pelvis (50%, 10/20 patients); 41.9% (122/291 patients) experienced recurrent disease or died. In patients with histologically-confirmed pelvic metastases after LAE, distant recurrences were most frequently observed (7/20 recurrences). Conclusions: A relevant risk regarding pelvic nodal involvement was observed from nodal status pN2a and higher. Our data support the omission of pelvic treatment in patients with nodal status pN1a and pN1b.

Hintergrund Die Notwendigkeit einer pelvinen Therapie bei Patientinnen mit nodal-positivem Vulvakarzinom (VSCC) und der Stellenwert der pelvinen Lymphonodektomie (LNE) als Staging-Verfahren zur Planung der adjuvanten Strahlentherapie (RT) sind umstritten.

The population at risk for pelvic disease in vulvar cancer is poorly described. This results in an overtreatment of a considerable proportion of patients with groin-positive disease. In this retrospective, multicenter analysis, 306 patients with primary node-positive vulvar squamous cell carcinoma (VSCC) after surgical groin staging treated at 33 gynecologic oncology centers in Germany between 2017- 2019 were analyzed with regard to pelvic treatment, risk for pelvic nodal involvement and prognosis. The majority had locally restricted tumors (T1b/T2; 292/306; 95.4%) with a median tumor diameter of 32 mm (2-110mm). Nodal status of the groin(s) was as follows: 23.9% (73/306) pN1a, 23.5% (72/306) pN1b, 20.4% (62/306) pN2a/b, and 31.9% (97/306) pN2c/pN3 (TNM staging system version 6). Only 35.6% (109/306) received a pelvic LAE – 39.4% unilaterally and 60.6% bilaterally; pelvic nodal involvement was observed in 18.5%. None of the patients with one intranodal metastasis or 2 metastases <5mm and pelvic LAE showed pelvic nodal involvement. Taking only patients with more inguinal disease into account, the rate of pelvic involvement was 25%. In total, adjuvant RT was applied in 64.4% (197/306). Only half of the patients who received pelvic LAE and had positive pelvic nodes received adjuvant RT to the pelvis (50%, 10/20 patients); 41.9% (122/291 patients) experienced recurrent disease or died. In patients with histologically confirmed pelvic metastases after LAE, distant recurrences were most frequently observed (7/20 recurrences). In case of histologically detected groin metastases, the risk for pelvic metastasis is low. These data no longer justify uncritical treatment of the pelvis - neither with surgery nor radiotherapy- in groin node-positive vulvar cancer.