What does 'stage 4 bladder cancer' mean?

What does 'stage 4 bladder cancer' mean?

Stage 4 bladder cancer refers to bladder cancer that has metasticized or spread from the bladder, the organ where it originated. Typically, bladder cancer spreads either through the lymph nodes or through the vascular system by gaining access to blood vessels. If it spreads through the lymph nodes, of course, it can enter the systemic circulation. If it enters the vasculature directly, then the cancer cells can spread throughout the body, and then implant into the bones, the skeleton, the lungs, the liver, the brain - much like any other tumor.