Role of Locoregional Treatment in Vulvar Cancer With Pelvic Lymph Node Metastases: Time to Reconsider FIGO Staging?

BACKGROUND: Vulvar cancer with pelvic nodal involvement is considered metastatic (M1) disease per AJCC staging. The role of definitive therapy and its resulting impact on survival have not been defined. PATIENTS AND METHODS: Patients with pelvic lymph node-positive vulvar cancer diagnosed in 2009 through 2015 were evaluated from the National Cancer Database. Patients with known distant metastatic disease were excluded. Logistic regression was used to evaluate use of surgery and radiation therapy (RT). Overall survival (OS) was evaluated with log-rank test and Cox proportional hazards modeling (multivariate analysis [MVA]). A 2-month conditional landmark analysis was performed. RESULTS: A total of 1,304 women met the inclusion criteria. Median follow-up was 38 months for survivors. Chemotherapy, RT, and surgery were used in 54%, 74%, and 62% of patients, respectively. Surgery was associated with prolonged OS (hazard ratio [HR], 0.58; P<.001) but had multiple significant differences in baseline characteristics compared with nonsurgical patients. In patients managed nonsurgically, RT was associated with prolonged OS (HR, 0.66; P=.019) in MVA. In patients undergoing surgery, RT was associated with better OS (3-year OS, 55% vs 48%; P=.033). Factors predicting use of RT were identified. MVA revealed that RT was associated with prolonged OS (HR, 0.75; P=.004). CONCLUSIONS: In this cohort of women with vulvar cancer and positive pelvic lymph nodes, use of RT was associated with prolonged survival in those who did not undergo surgery. Surgery followed by adjuvant RT was associated with prolonged survival compared with surgery alone.