To describe the natural history of untreated muscle invasive bladder cancer (MIBC) and compare the oncological outcomes of treated and untreated patients.

We utilized a database encompassing all patients with newly-diagnosed bladder cancer in Stockholm, Sweden between 1995-1996. The median follow-up for survivors was 14.4 yrs. Overall, 538 patients were diagnosed with BC of whom 126 patients had clinically localized MIBC. Patients were divided in two groups: those who received radical cystectomy or radiation therapy and those who did not receive any form treatment. Multivariable Cox or competing risks regressions were adopted to predict metastasis, overall survival (OS) and cancer specific mortality (CSM), when appropriate. Analyses were adjusted for age at diagnosis, sex, tumor stage, clinical N stage and treatment.

64 (51%) patients did not receive any definitive local treatment. In the untreated group, median (IQR) age at diagnosis was 79 (63-83) yrs versus 69 (63-74) in the treated group (p<0.001). Overall, 109 patients died during follow-up. At 6 mo after diagnosis, 38% of the untreated patients had developed metastatic disease and 41% experienced CSM. The 5-yr OS rate for untreated and treated patients was 5% (95%CI: 1,12%) versus 48% (95%CI: 36,60%), respectively. Patients not receiving any treatment had a 5-yr cumulative incidence of CSM of 86% (95%CI: 75,94%) versus 48% (95%CI: 36,60%) for treated patients. Untreated patients had a higher risk of progression to metastatic disease (HR: 2.40; 95% CI: 1.28,4.51; p=0.006), death from any cause (HR:2.63; 95%CI: 1.65,4.19; p<0.001) and CSM (SHR:2.02; 95%CI: 1.24, 3.30; p=0.004).

Untreated patients with MIBC are at very high risk for near term cancer specific mortality. These findings may help balance the risks versus benefits of integrating curative intent therapy particularly in older patients with MIBC. This article is protected by copyright. All rights reserved.

BJU international. 2019 Jul 16 [Epub ahead of print]

Alberto Martini, John P Sfakianos, Lotta Renström-Koskela, Ashkan Mortezavi, Ugo Giovanni Falagario, Lars Egevad, Abolfazal Hosseini, Reza Mehrazin, Matthew D Galsky, Gunnar Steineck, N Peter Wiklund

Department of Urology, Icahn School of Medicine at Mount Sinai, New York, New York., Karolinska Institutet, Department of Molecular Medicine and Surgery, section of Urology, Stockholm, Sweden., Karolinska Institutet, Department of Medical Epidemiology and Biostatistics, Stockholm, Sweden., Karolinska Institutet, Department of Oncology-Pathology, Stockholm, Sweden., Division of Hematology and Oncology, Department of Medicine, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York., Sahlgrenska Academy Clinical Sciences, University of Göteborg.