Adjuvant Radiation Therapy for High Stage Urothelial Carcinoma of the Upper Urinary Tract

Abstract

The role of adjuvant radiation therapy after curative surgery to high stage urothelial carcinoma (transitional cell carcinoma) of the renal pelvis and ureter has not been proved in large randomized controlled trials and is controversial in clinical practice because of its rarity. Furthermore, the NCCN guideline has mentioned about the role of adjuvant chemotherapy (CT) but not adjuvant radiotherapy (RT) in such patents. The aim of this study is to define the benefit of adjuvant RT following curative surgery of high stage urothelial carcinoma of the upper urinary tract (UTUC) by determining the clinical outcomes. Between 2006 and 2015, patients with pathologic T3/4 and/or N+ UTUC who underwent nephroureterectomy with bladder cuff resection (NUR+BCR) were retrospectively examined at our institution. The administration of adjuvant RT or CT was at physician’s discretion. The Kaplan-Meier method was used to estimate cancer-specific survival (CSS), locoregional recurrence-free survival (LRFS), bladder recurrence-free survival (BRFS) and distant metastasis-free survival (DMFS). Differences in risk-adjusted outcomes between RT and non-RT groups were assessed using a multivariate Cox proportional Hazards model. A total of 106 patients had pT3-4 and/or N+ UTUC. Postoperative RT was administered in 20 (18.9%) of patients. Median dose of RT was 50.4 Gy (range, 45.0 to 64.8 Gy). With a median follow-up of 29.3 months, 3-year CSS were 84.4% vs. 73.1% (p=0.320), 3-year LRFS were 81.5% vs. 60.9% (p=0.102), 3-year BRFS were 92.3% vs. 77.4% (p=0.306) and 3-year DMFS were 73.1% vs. 59.1% (p=0.386) in the RT vs. non-RT groups, respectively. On multivariate analysis, patients with the administration of adjuvant RT had a better LRFS (HR, 0.04; 95% CI 0.002 to 0.591; p=0.02) and better trend in CSS (HR, 0.12; 95% CI, 0.01 to 1.12; p=0.06). However, no statistically significant difference in BRFS and DMFS between RT and non-RT groups could be demonstrated. Adjuvant RT following curative surgery may improve locoregional control and potentially improve survival in patients with high stage UTUC. Beyond the NCCN guideline suggestion other than adjuvant CT for such patients, adjuvant RT may be another considerable modality for such patients, especially as an alternative treatment for patient who is not suitable to receive CT.