Phase II study of definitive chemoradiation for locally advanced squamous cell cancer of the vulva:An efficacy study

OBJECTIVE: To evaluate feasibility of chemoradiation as alternative for extensive surgery in patients with locally advanced vulvar cancer and to report on locoregional control, toxicity and survival.METHODS: In a multicenter, prospective phase II trial patients with locally advanced vulvar cancer were treated with locoregional radiotherapy combined with sensitizing chemotherapy (capecitabine). Treatment feasibility, percentage locoregional control, survival and toxicity were evaluated.RESULTS: 52 patients with mainly T2/T3 disease were treated according to the study protocol in 10 centers in the Netherlands from 2007 to 2019. Full dose radiotherapy (tumor dose of 64.8Gy) was delivered in 92% and full dose capecitabine in 69% of patients. Most prevalent acute ≥ grade 3 toxicities were regarding skin/mucosa and pain (54% and 37%). Late ≥grade 3 toxicity was reported for skin/mucosa (10%), fibrosis (4%), GI incontinence (4%) and stress fracture or osteoradionecrosis (4%). Twelve weeks after treatment, local clinical complete response (cCR) and regional control (RC) rates were 62% and 75%, respectively. After 2 years, local cCR persisted in 22 patients (42%) and RC was 58%. Thirty patients (58%) had no evidence of disease at end of follow-up (median 35 months). In 9 patients (17%) extensive surgery with stoma formation was needed. Progression free survival was 58%, 51% and 45% and overall survival was 76%, 66%, 52% at 1,2, and 5 years.CONCLUSIONS: Definitive capecitabine-based chemoradiation as alternative for extensive surgery is feasible in locally advanced vulvar cancer and results in considerable locoregional control with acceptable survival rates with manageable acute and late toxicity.