Five-year overall survival of patients with advanced bladder cancer in Kazakhstan: OSURK registry study.

Background: The goals of the OSURK registry study were to assess 5-year overall survival (OS) in patients with metastatic urothelial cancer diagnosed in 2017 in Kazakhstan and collect data on the use of various treatment options in routine clinical practice.

Methods: Patients with newly diagnosed metastatic bladder cancer (BC) were retrospectively identified in the national register of Kazakhstan (ERCP) between January 2017 and January 2018. ERCP is the biggest register in the country and includes patient data from 17 regions. Investigators collected patient information and processed records online on the following anonymised data: demographical characteristics, received treatment and outcomes. Patients were included in the study if mBC was confirmed histologically and they had at least one visit to the cancer center during the follow-up period. The outcomes of interest were overall survival (OS), patient characteristics and treatment patterns.

Results: Totally 480 adult patients with metastatic BC were included. Mean number of patients in one region per year was 28.2. Median age at diagnosis of mBC was 70.0 years (range, 30-100). Patients were predominantly male (81.3%), histological subtype of BC (urothelial carcinoma, etc.) was determined in 41%. Overall, 187 (39%) patients received systemic therapy for metastatic disease. Platinum-based chemotherapy was prescribed in 147 (76.8%) patients who received systemic treatment. The majority of treatment was with cisplatin (N=132, 70.6%). Sixty-four (13.3%) patients received ≥2 treatment lines. After median 60.5 months of follow-up the 5-year OS in patients with metastatic BC was 2.7%. The 1-, and 3-year OS rates were 31.0% and 9.8%, respectively. Median OS from the start of treatment was 7.3 months (95% CI 6.5-8.1).

Conclusions: The results of the OSURK study indicate the need for further implementation of innovative drugs in real practice in order to significantly increase the OS of patients with metastatic BC.