Ten-year data on 138 patients with endometrial carcinoma and postoperative vaginal brachytherapy alone: No need for external-beam radiotherapy in low and intermediate risk patients

Objective.: To evaluate long-term outcome, risk factors, and causes of death in stage I-IIIA endometrial carcinoma (EC) patients treated only with adjuvant vaginal brachytherapy (VB) and to clarify for which subgroups of patients it is safe to omit external-beam radiotherapy (EBRT). Methods.: Out of 224 EC patients receiving postoperative radiotherapy between 1990 and 2002, 138 had VB alone in curative intent (FIGO [2002]: 85%I, 12%II, 3%IIIA; 18 low risk [IA G1-2, IB G1], 103 intermediate risk [IB G2-3, IC G1-2, IIA-B G1-2], 17 high risk [IC G3, IIIA]). After surgery ± lymphadenectomy, HDR-brachytherapy prescription (in 95.7% of patients) was 3 × 10 Gy to the surface or 3 × 5 Gy at 5 mm tissue depths. Results.: Median follow-up was 107 months (range 3-185). Three intermediate and 7 high risk-patients relapsed. The 10-year vaginal control was 99.2%, locoregional control was 95.2% (low/intermediate/high risk: 100%/98.9%/68.8%), and disease-free survival (DFS) was 91.7% (100%/96.8%/55.2%). Risk factors for poor DFS were lymphovascular space invasion, ≥ 50% myometrial invasion (univariate, p < 0.05), pathological FIGO-stage, and grade 3 (uni-/multivariate, p < 0.05). Leading causes of deaths (n = 41) were cardiovascular disease (29%) and other malignancies (24%) ahead of EC (19.5%). The 10-year overall survival was 68.5% and the disease-specific survival was 92.4%. Thirty-five secondary tumors in 31 patients led to a higher actuarial death rate (10-year 9.9%, 15-year 17.7%) than EC (7.6%). Conclusions.: Restricting adjuvant therapy to VB alone seems to be safe in low and intermediate risk EC and can be recommended. As death rarely relates to early-stage EC, value of adjuvant therapy is probably better reflected by DFS rather than by overall survival.