Once cancer has been diagnosed, the next step is to choose the best way to treat it. To help do this, your healthcare provider checks how deep the cancer has grown and whether it has spread. (This is called the cancer stage.)
As cancer cells multiply, the tumor grows. Bladder cancer begins in the inner lining of the bladder, and often doesn’t grow beyond that layer. As the tumor gets larger, it may invade (grow into) deeper layers of the bladder. It may also invade nearby organs, such as the prostate in men or the uterus in women. Cells can break off from the main tumor and enter the bloodstream or lymph nodes. Blood or lymph then carries the cells to other areas of the body, such as the bones, liver, or lungs, where a new growth may form. This process is called metastasis. The stage of cancer is based on where the cancer is and how much it has grown and spread. The stage is found by looking inside the bladder during cystoscopy and using tests that show images of the bladder, the areas around it, and parts of the body that the cancer may spread to. The staging system described below is a simplified one. Your healthcare provider will most likely use a similar, but more detailed, system.
At the superficial stage (noninvasive), the tumor is confined to the bladder lining and submucosal layer of the bladder.
At the invasive stage, the tumor has begun to grow into the muscle or fat layers of the bladder.
At the metastatic stage, cancer cells from the main tumor have spread beyond the bladder to other areas of the body.