Background: There is limited information about survival effect of vaginal brachytherapy (VBT) and its comparison to external beam pelvic radiotherapy (EBRT) and no radiotherapy (no-RT) of endometrial cancer patients.
Patients and methods: We performed a multicenter retrospective registry study of 1550 patients with endometrial cancer treated by no-RT (n = 702), VBT (n = 430) and EBRT ± VBT (n = 418). The outcome measure was overall survival.
Results: RT did not improve the overall survival of patients with a low risk of recurrence. In univariate analysis, the survival effect of VBT was significant in patients with intermediate and high risk of recurrence (HR 0.42, CI 0.29-0.60, p < 0.0001). EBRT ± VBT demonstrated no survival effect in these groups. Multivariate analysis showed that VBT (HR 0.50, CI 0.36-0.71) significantly reduced the mortality risk in patients with an intermediate and high risk compared with no-RT after adjustment for age, tumor grading, tumor stage, lymphadenectomy, adjuvant therapy and comorbidities. Matching for age, histological type, tumor stage, tumor grade, and performance status between patients treated with no-RT and VBT was performed. The matching analysis again demonstrated the favorable survival effect of VBT compared to no-RT on overall survival with an absolute risk reduction of 17.7%. Notably, in a further 106 matched pairs, EBRT ± VBT did not demonstrate any survival effect over VBT among patients at intermediate and high risk of recurrence.
Conclusions: VBT should be performed in patients at intermediate and high risk of recurrence of endometrial cancer, after operative determination of lymph node status.
Keywords: EBRT; Endometrial cancer; VBT.