Most guidelines advise no adjuvant radiotherapy in vulvar squamous cell carcinoma and a single occult intracapsular lymph node metastasis. However, several recent studies have questioned the validity of this recommendation. The aim of this study was to analyze the groin recurrence rate in patients with a single intracapsular positive lymph node treated without adjuvant radiotherapy.

Patients with a single clinically occult intracapsular lymph node metastasis, treated without adjuvant radiotherapy, formed the basis for this study. Groin recurrences, and the risk of death, were analyzed in relation to the size of the metastasis in the lymph node and the lymph node ratio. Data were analyzed using SPSS, version 26.0 for Windows.

After a median follow-up of 64 months, one of 96 patients (1%) was diagnosed with an isolated groin recurrence and another two (2.1%) were diagnosed with a combination of a local and a groin recurrence. The only isolated groin recurrence occurred in a contralateral lymph node negative groin. Size of the metastasis and lymph node ratio had no impact on the groin recurrence risk, nor on survival. The 5-year actuarial disease-specific and overall survivals were 79% and 62.5% respectively. The 5-year actuarial groin recurrence-free survival was 97%.

Because of the low risk of groin recurrence and the excellent groin recurrence-free survival, we recommend that adjuvant radiotherapy to the groin in patients with vulvar squamous cell carcinoma and a single occult intracapsular lymph node metastasis can be safely omitted to prevent unnecessary toxicity and morbidity.