Cohort profile: Bladder Cancer Data Base Sweden (BladderBaSe) 2.0

PURPOSE: We constructed Bladder Cancer Data Base Sweden (BladderBaSe) 2.0 to expand studies in BladderBaSe on incidence, treatment outcomes, side effects, survival and health economic aspects of men and women with cancer in the urinary bladder, upper tract urothelial carcinoma (UTUC) (renal pelvis and ureter) and urethral carcinoma. PARTICIPANTS: BladderBaSe 2.0 includes 53 298 patients with cancer in the urinary bladder, diagnosed from 1 January 1997 to 31 December 2019, and 961 patients with UTUC in the renal pelvis and 792 in the ureter, and 146 patients with urethral urothelial carcinoma, diagnosed from 1 January 2015 to 31 December 2019, and in total 275 816 participants in reference groups, free of cancer in the urinary tract, matched 1:5 on sex, age and county. FINDINGS TO DATE: To date, 18 published studies based on data from the BladderBaSe have investigated calendar time trends in survival; impact of gender, socioeconomic factors, tumour aggressiveness and hospital volume for radical cystectomy on prognosis; survival after radical cystectomy compared with radical radiotherapy; risk factors for complications and side effects after radical cystectomy such as thromboembolism, strictures of ureteroenterostomies and incisional hernia. FUTURE PLANS: The BladderBaSe initiators are currently investigating gender-dependent detection delays due to urinary tract infections; survival after non-muscle invasive bladder cancer with respect to the number of transurethral resections; short-term outcomes comparing open and robot-assisted radical cystectomy; studies on risk for intravesical recurrence after different diagnostic measures in UTUC, and suicide risk after bladder cancer diagnosis. The BladderBaSe project group is open for collaborations with national and international colleagues.