Hospital variation in treatment patterns and oncological outcomes for patients with muscle-invasive and metastatic bladder cancer in the Netherlands.

ABSTRACT

PURPOSE: Population-based studies on treatment patterns in oncology and corresponding clinical outcomes can help identify strategies towards optimal value for patients. This study was performed to describe the variation in treatment patterns and major oncological outcomes for muscle-invasive or metastatic bladder cancer (MIBC/mBC) patients in the Netherlands. METHODS: Patients diagnosed with cT2-4aN0-3M0-1 disease between 2008 and 2016 in seven large teaching hospitals in the Netherlands were included. Baseline characteristics, disease stage, intended and definitive treatment, and oncological outcomes were collected. Patients were categorized based on cTNM-stage (1) cT2-4aN0M0, (2) cT2-4aN1-3M0 and (3) cT4b and/or M1. RESULTS: The total study population comprised 1853 patients, of which 1303 patients were diagnosed with cT2-4aN0M0 disease. Overall, curative treatment was intended in 81% (range 74-85%, P value = 0.132). Radical cystectomy (RC) and curative radiotherapy (RTx) ranged between hospitals from 42 to 66% and 13 to 27%, respectively (P value < 0.001). For 334 patients staged cT4b and/or M1, frequencies for palliative therapy and best supportive care (no anti-cancer therapy) ranged between hospitals from 20 to 54% and 44 to 71%, respectively (P value < 0.001). There was no association between hospital site and overall survival (OS) in a univariable and multivariable Cox regression for survival analysis (after adjusting for age and cT-stage), for all three cTNM-groups. Neoadjuvant or induction chemotherapy (NAIC) utilization rates before RC ranged from 8 to 38% (P value < 0.001). CONCLUSIONS: There is large inter-hospital variation in treatment intent in MIBC/mBC patients. This variation does not seem to translate to differences in overall survival rates. There is an ongoing trend of increased use of RC. Utilisation of NAIC is relatively low considering European guideline recommendations.