Initial management and survival of patients with primary metastatic bladder cancer before the immunotherapy era: a population-based study from Norway

Abstract

Before immunotherapy became part of the management of metastatic bladder cancer (mBC), systemic anti-cancer treatment comprised primarily of platinum-based chemotherapy. The objective of this study was to describe the characteristics, the initial management, overall survival (OS) and hospitalisations of patients with mBC before 2018 when immunotherapy for mBC was introduced in Norway. Material and methods: It is a nationwide population-based study of primary mBC patients (diagnosed 2008-16). Descriptive statistics were applied and stratified for four initial management options (≤150 days after BC diagnosis): chemotherapy, major local treatment (cystectomy/pelvic radiotherapy), multimodal treatment (chemotherapy and local) and no anti-cancer treatment beyond transurethral resection of bladder tumour (untreated). Group differences were evaluated by Chi-square and Kruskal–Wallis test; OS was estimated with Kaplan–Meier. Results: Of the 305 patients included, 76 (25%) patients had chemotherapy, 46 (15%) patients had major local treatment, 21 (7%) patients had multimodal treatment and 162 (53%) patients were untreated. Median OS ranged from 2.3 months (untreated) to 9.8 months (chemotherapy). Patients who received treatment had a higher rate of hospitalisation, with a median stay of three to four times that of untreated patients. Conclusion: Before immunotherapy, more than 50% of patients with primary mBC did not receive any initial anti-cancer therapy and had a poor survival. Patients treated with chemotherapy had inferior median OS compared to those treated with comparable systemic strategies in contemporary trials. Our results provide a basis for future research on treatment and survival after the introduction of immunotherapy for mBC, aiming to improve the care and outcome of patients with mBC.