Adjuvant pelvic radiotherapy for pathological high-risk muscle-invasive bladder cancer: A multicenter retrospective study.

Abstract

369 Background: Radical cystectomy (RC) and pelvic lymph-node dissection (PLND) are standard procedures in the management of non-metastatic muscle invasive bladder cancer (MIBC). Loco-regional recurrence (LRR) is a common early event associated with a poor prognosis. The aim of this study is to evaluate adjuvant radiotherapy (RT) for pathological high-risk MIBC. Methods: We retrospectively reviewed data from patients treated by RC from 3 institutions. Inclusion criteria were MIBC, histologically proven urothelial carcinoma treated by RC and adjuvant RT. Patients with conservative surgery were excluded. LRR free-survival, overall survival (OS) and metastasis-free survival (MFS) were evaluated. Acute toxicities were recorded according to CTCAE V4.0 scale. Results: Between January 2000 and December 2013, 57 patients with a median age of 66 years (45-84) were included. Post-operative pathological staging was pT2, pT3 and pT4 in 16%, 44%, and 39%, respectively. PLND revealed 28% of pN0, 26% of pN1 and 42% of pN2. For 2 patients, no PLND was performed. Median number of lymph-nodes retrieved was 10 (2-33). Forty-eight patients (84%) received platin-based chemotherapy, 7 in neo-adjuvant and 41 in adjuvant setting. For RT, clinical target volume 1 (CTV 1) alwyas encompasses pelvic lymph nodes and cystectomy bed for 37 patients (65%). Median dose for CTV 1 was 45 Gy (4-50). Dose complement of 16 Gy (5-22) corresponding to CTV 2 was achieved in 53 of cases, depending on pathological features. Intensity Modulated RT was performed in one third of patients. With a median follow-up of 40.4 months, LRR occurred in 8 patients (14%). Three-year loco-regional free survival, MFS and OS were 45% (IC 95%: 0.30-0.60), 39% (IC 95%: 0.25-0.52) and 49% (IC 95%: 0.33-0.63), respectively. Acute grade ≥ 3 toxicities were observed in 5 patients (9%). One patient died with intestinal fistula in septic context. No survival or toxicity predictive factor was identified. Conclusions: Adjuvant radiotherapy for pathological high-risk MIBC is safe and may have oncological benefits. Thus, new prospective trials evaluating this approach with modern RT techniques should be undertaken.