Vaginal brachytherapy alone for patients with Stage II endometrial cancer with inner half cervical stromal invasion

The purpose of this study was to review outcomes of women with Stage II endometrial carcinoma with inner half cervical stromal invasion treated with adjuvant vaginal brachytherapy (VB) alone.

A single-institution retrospective chart review identified consecutive patients with Stage II endometrial cancer and inner half cervical stromal invasion treated with VB alone from 2011 to 2015. Patients who received chemotherapy or external beam radiotherapy were excluded. Patient and disease characteristics were collected. Association between variables and outcomes were assessed using Fisher's exact or Wilcoxon rank sum test.

Fifty-seven patients were identified over 5 years with a median followup of 46.8 months. Carcinoma was endometrioid Grade 1 (43.9%), 2 (36.8%), 3 (5.3%), or serous (14.0%). Depth of myometrial invasion was inner half in 75.4%. Lymphovascular invasion was seen in 28.1%, and lymph node assessment was performed in 43.9% of patients. The median depth of cervical stromal invasion was 1.25 mm (n = 48 patients). The median percentage of the cervical stromal wall invaded by tumor (obtained in 40 patients) was 16.7%. Seven (12.3%) patients recurred at a median of 16.9 months. Five-year estimates of progression-free survival and overall survival were 81.5% and 78.5%, respectively. The only factor associated with recurrence, progression-free survival or overall survival on bivariate analysis was high-grade (Grade 3 or serous) disease (p = 0.031).

VB alone can be considered for Stage II patients with inner half cervical stromal invasion and Grade 1-2 disease. Systemic therapy may be required for patients with Grade 3 and serous histology as 75% (3/4) of these recurrences were outside the pelvis.