A Real-world Study of the First Treatment and Outcomes of Patients With Advanced or Metastatic Bladder Cancer

Bladder cancer (urothelial carcinoma) is a disease where cells in the bladder grow out of control. The bladder is an organ in the lower part of the body that stores urine. When someone has bladder cancer, abnormal cells form in the bladder and can spread to other parts of the body if not treated. Bladder cancer that has spread outside the bladder is called advanced or metastatic bladder cancer. The purpose of this study is to examine how long it takes for adults with advanced or metastatic bladder cancer to experience worsening of their disease following their first treatment . The researchers will also describe which medicines these patients use as their first treatment for the disease. This is a real-world study, not a clinical study. This means that researchers will look at what happens when patients receive the treatments prescribed by their own doctor as part of their usual healthcare treatment. In this study, researchers will use information from cancer clinics (Flatiron Health electronic health records). The study will include patients' information from the database who: * Were identified to have advanced or metastatic bladder cancer. * Started their first treatment after 01 Apr 2023. * Were 18 years of age or older when they were diagnosed with advanced disease.