Purpose: To evaluate locoregional control, disease free survival, and overall survival in patients treated with surgery and adjuvant radiation for stage II adenocarcinoma of the endometrium. Secondary goals include identification of prognostic factors and the comparison of toxicity profiles after vaginal cuff brachytherapy (VB) alone or combined with pelvic external beam radiation therapy (EXT).
Materials and methods: All patients receiving adjuvant radiation at the University of Wisconsin following surgery for FIGO stage II adenocarcinoma of the endometrium between January 1991 and December 2006 were retrospectively reviewed.
Results: Between January 1991 and December 2006, 71 patients with FIGO stage II adenocarcinoma of the endometrium (23 stage IIA, 48 stage IIB) received adjuvant radiation at the University of Wisconsin. Fifty patients were treated with EXT and VB, twenty with VB alone, and one with EXT alone. At a mean follow-up of 5.1 years (range, 0.5-16.8 years), 5-year overall and disease-free survival were both 82%. Factors associated with an increased risk for recurrence include depth of myometrial invasion (p=0.005) and lymphovascular invasion (p=0.02). Receiving EXT was significantly associated with increased depth of myometrial invasion (p=0.007), higher grade (p=0.003), and less extensive surgery (p=0.01). Of the nine recurrences, three were initially local and six were distant recurrences alone. Grade 2 or greater acute and late side effects were significantly greater with EXT therapy compared to VB alone (p<0.0001 and p=0.02, respectively), although severe toxicities (grade 3 or greater) were limited with either modality.
Discussion: Local recurrence rates remain low after surgery and adjuvant radiation therapy for stage II endometrial cancer using a combination of VB and EXT tailored to the surgical and pathologic features. VB alone resulted in fewer toxicities without an increased recurrence risk compared to the combination of EXT and VB, suggesting that VB without EXT is sufficient for patients with low-risk histopathologic features and comprehensive surgical staging with complete lymphadenectomy.