ObjectivesTreatment of clinical early-stage endometrioid endometrial cancer (EEC) in The Netherlands consists of primary hysterectomy and bilateral salpingo-oophorectomy. Adjuvant radiotherapy is given when 2 or more the following risk factors are present: 60 years or older, grade 3 histology, and 50% or more myometrial invasion. Lymphovascular space invasion (LVSI) is a predictor of poor prognosis and early distant spread. It is unclear whether adjuvant radiotherapy is sufficient in patients with LVSI-positive EEC.Methods/MaterialsEighty-one patients treated from 1999 until 2011 for stage I LVSI-positive EEC in 11 Dutch hospitals were included. The outcomes of patients with 0 to 1 risk factors were compared with those with 2 to 3 risk factors, and both were compared with the known literature.ResultsEighteen patients presented with recurrent disease, and 12 of those recurrences had a distant component. Overall and distant recurrence rates were 19.2% and 11.5% in patients with 0 to 1 risk factors followed by observation and 25.5% and 17% in patients with 2 to 3 risk factors who received adjuvant radiotherapy. Only 1 patient with grade 1 disease had a recurrence.ConclusionsIn stage I LVSI-positive EEC with 0 to 1 risk factors, observation might not be adequate. Moreover, despite adjuvant radiotherapy, a high overall and distant recurrence rate was observed in patients with 2 to 3 risk factors. The use of systemic treatment in these patients, with the exception of patients with grade 1 disease, should be investigated.