Impact of a Dedicated Multidisciplinary Research and Treatment Network on Outcomes of Muscle-Invasive Bladder Cancer Patients

Background: The Dutch Uro-Oncology Study Group (DUOS) is a multidisciplinary network of ~30 hospitals involved in research and treatment of urological cancers. We analyzed the influence of treatment at DUOS versus non-DUOS on survival of muscle-invasive bladder cancer (MIBC) patients and explored correlating parameters. Patients and methods: Characteristics of 3472 cT24aN0/XM0 MIBC patients who underwent radical cystectomy (RC), with or without neoadjuvant chemotherapy (NAC), were collected by the Netherlands Cancer Registry (NCR). 5-year overall survival (OS) was estimated by the Kaplan-Meier method. Cox regression analyses were performed to determine hazard ratios for pre-defined variables. Results: 5-year OS differed 3.2% in favor of DUOS centers (49.3% vs. 46.1%, p = 0.09). Best survival was observed in patients treated with NAC and RC at DUOS centers (5year OS 57%). This was 61.1% in cT3-4 patients treated at DUOS centers. NAC was only significantly associated with improved survival in cT3-4a patients treated at DUOS centers (p = 0.0002). Positive surgical margins were less frequent (p = 0.02) and more pelvic lymph nodes (LNs) were collected and identified (p = 0.001) at DUOS centers. Surgical margins, number of identified LNs, and number of positive LNs significantly correlated with OS. Conclusions: We identified a greater survival benefit by the use of NAC, a higher number of LNs identified, a lower rate of positive surgical margins and a trend towards survival benefit in patients treated at centers that collaborate in the multidisciplinary DUOS national network. Implications for practice: Our retrospective analysis based on 3472 muscle-invasive bladder cancer patients, showed a non-significant trend towards survival benefit when treated in hospitals involved in a national study-group network (DUOS), with significantly superior outcomes concerning neo-adjuvant chemotherapy, surgical margins and lymph node dissection. These factors significantly correlated with an improved survival, favoring treatment at centers that are involved in a multidisciplinary national network with dedicated care for bladder cancer.