Adjuvant Radiotherapy in High-Risk Squamous Cell Carcinoma of the Vulva: A Two-Institutional Italian Experience

Background: The aim of this study was to assess the treatment benefit and patterns of recurrence for patients with high-risk vulvar squamous cell carcinoma treated with surgery followed by adjuvant radiotherapy (RT). Patients and Methods: From January 1999 to June 2016, 51 patients underwent total or partial deep vulvectomy with inguinofemoral lymphadenectomy followed by adjuvant RT with 45-50 Gy in 25 fractions +/- a 4-10 Gy boost. 17 (33.3%) women received concomitant chemotherapy. Results: Median overall survival was 81 months. The 5-year disease-free survival and overall survival rates were 52 and 63%, respectively. In univariate and multivariate analysis, patients aged ≤ 76 years and those receiving an RT total dose of > 54 Gy had a significantly lower risk of progression (p = 0.044 and 0.045; p = 0.012 and 0.018, respectively) and death (p = 0.015 and 0.011; p = 0.015 and 0.026, respectively). There was a trend towards a lower risk of progression for patients with tumor size ≤ 4 (p = 0.098) and negative lymphovascular space involvement (p = 0.080). Also, there was a trend towards a higher risk of death (p = 0.075) for grade 3 tumors. Concomitant chemotherapy provided no significant benefit. Conclusion: Only age and RT total dose are significant prognostic variables for squamous cell carcinoma of the vulva treated with primary surgery and adjuvant RT to improve local and locoregional control.