Risk of bladder cancer death in patients younger than 50 with non-muscle-invasive and muscle-invasive bladder cancer.

Bladder cancer is primarily a disease of older age and little is known about the differences between patients diagnosed with bladder cancer at a younger versus older age. Our objectives were to compare bladder cancer specific survival in patients aged <50 versus those aged 50-70 at time of diagnosis. The Swedish bladder cancer database provided data on patient demographics, clinical characteristics and treatments for this observational study. Cox proportional hazard regression models were adjusted for appropriate variables. All analyses were stratified by disease stage (non-muscle-invasive bladder cancer and muscle-invasive bladder cancer. Furthermore, we compared the frequency of lower urinary tract infections within 24 months prior to bladder cancer diagnosis by sex and age groups. The study included 15,452 newly-diagnosed BC patients (1997-2014); 1,207 (8%) patients were <50 whilst 14,245 (92%) were aged 50-70. Patients aged <50 at diagnosis were at a decreased risk of bladder cancer death (HR = 0.82, 95%CI: 0.68-0.99) compared to those aged 50-70. When stratified by non-muscle-invasive and muscle-invasive bladder cancer, this association remained in non-muscle-invasive patients only (<50, HR = 0.43, 95% CI: 0.28-0.64). The frequency of lower urinary tract infection diagnoses did not differ between younger and older patients in either men or women. Patients diagnosed with non-muscle-invasive bladder cancer when aged <50 are at decreased risk of bladder cancer-specific death when compared to their older (50-70) counterparts. These observations raise relevant research questions about age-related differences in diagnostic procedures, clinical decision-making and, not least, potential differences in tumour biology.