Introduction

Local failure (LF) after radical cystectomy (RC) due to bladder cancer (BCa) is a common and deadly event. Clinical trials are currently evaluating the impact of adjuvant radiotherapy on the reduction of LF, however scarce data exists about selection of candidates who might benefit from multimodal approach.

Methods

We focused on 1112 patients treated with RC and pelvic lymph node dissection, between 1990 and 2012, at a single tertiary referral center. LF was defined as imaging evidence of recurrence in the pelvic soft tissues or nodes below the aortic bifurcation before or within 3 months of detection of distant metastases. Kaplan-Meier log-rank, univariable and multivariable competing risk analyses tested the relationship between clinical and pathological factors and the risk to develop LF during follow up period. Regression tree analysis stratified patients into risk-groups based on their tumor characteristics and the corresponding LF rate.

Results

Of the 1,122 individuals included in the study, 50 (4.5%) developed LF during follow up period. Median (IQR) follow-up was 62 (35-92) months. At univariable competing risk regression, pathological T stage pT4 vs. pT3 (Hazard Ratio [HR]: 2.55, p=0.003), positive soft tissue surgical margin (STSM) vs. negative (HR: 2.95, p=0.005) and non-pure transitional vs. pure transitional histology (HR: 1.79, p=0.03) were associated with an increased risk of developing LF. On the basis of these variables, the cohort was stratified into four risk groups: very low risk (?pT3a disease, pure transitional histology and negative STSM), low risk (?pT3a disease, non-pure transitional histology and negative STSM), intermediate risk (pT4 disease, negative STSM and any histology), and high risk (all patients with positive STSM).

Conclusions

LF is a common event in RC patients. We developed a new risk model based on BCa characteristics. Our findings should be considered by threating physicians when deciding the necessity of adjuvant radiotherapy.

Funding

none