Rationale:~Standard treatment of early stage vulvar cancer is a wide local excision of the primary tumor combined with the sentinel node (SN) procedure for the groins. An inguinofemoral lymphadenectomy (IFL) is only indicated in case of a positive SN. An IFL is associated with major morbidity, e.g. wound healing problems, lymphoceles, lymphedema of the legs and recurrent infections. GROINSS-V II investigated whether radiotherapy would be a safe alternative for IFL in case of SN metastasis. The results for radiotherapy in the group with metastasis ≤ 2mm are promising. This study also showed that for metastasis > 2mm, only radiotherapy was not efficient. The efficacy of treatment can be increased by adding chemotherapy or giving a higher dose of radiotherapy. GROINSS-V III will investigate this regimen.~Objective:~The primary objective of this study is to investigate the safety of replacing inguinofemoral lymphadenectomy by chemoradiation in early stage vulvar cancer patients with a macrometastasis (>2mm) and/or extracapsular extension in the SN. The secondary objective is to evaluate the short and long-term morbidity associated with the SN procedure and chemoradiation.~Study design: Phase II treatment trial, with stopping rules for the incidence of groin recurrences.~Study population: early-stage vulvar cancer patients with a metastasis > 2mm in their SN, or more than one metastasis ≤ 2mm.~Intervention: Participants will be treated with chemoradiation, in a total dose of 56Gy to the involved site, combined with weekly cisplatin 40mg/m2~Main study parameters/endpoints: The primary endpoint is the groin recurrence rate in the first 2 years after primary treatment.~Nature and extent of the burden and risks associated with participation, benefit and group relatedness: participants will be treated with chemoradiation during 5 weeks instead of surgical treatment. There is a risk that this treatment will not be as effective as surgical treatment, which may lead to more groin recurrences which are hard to treat. By continuously monitoring the groin recurrence rate the investigators will notice activation of the stopping rule as early as possible.
Vulvar cancer patients with SN-metastasis > 2mm will receive chemoradiation instead of an inguinofemoral lymphadenectomy.