Objective: To identify factors predictive of vaginal relapse in stage I endometrial cancer, thereby potentially facilitating the selection of patients who may benefit from vaginal brachytherapy.
Methods: The study population included 632 patients with stage I endometrial cancer managed with hysterectomy at our institution between 1984 and 1996. Median follow-up was 73 months; 122 patients (19%) received adjuvant radiotherapy.
Results: Overall, 2.9% of the stage I cohort developed vaginal relapse at 5 years. Vaginal relapse was observed in 1.7% of patients who received radiotherapy and in 3.0% of those whose treatment did not include radiotherapy (P = 0.36). Cox regression analysis (including radiotherapy) identified only grade 3 differentiation (hazard ratio = 3.83, P = 0.007) as an independent predictor of vaginal relapse. Patients with a low-grade tumor had a 5-year vaginal relapse rate of 2%, compared with 7% for those with a grade 3 tumor. When only patients who did not receive adjuvant radiotherapy were considered, both grade 3 tumor and lymphovascular invasion were significant predictors of vaginal relapse (P < 0.05). When neither variable was present, 2% of patients experienced vaginal relapse at 5 years, compared with 11% when either 1 was present (P < 0.001). Depth of myometrial invasion was not a significant predictor of vaginal recurrence.
Conclusion: Histologic grade 3 tumor and lymphovascular invasion were the cogent predictors of vaginal relapse in our population. The cost and morbidity of vaginal brachytherapy should be balanced against the potential risk of vaginal relapse in this group of patients.