Bladder cancers are classified, or staged, based on their aggressiveness and how much they differ from the surrounding bladder tissue. There are several different ways to stage tumors. Recently, the TNM (Tumor, Nodes, Metastasis) staging system has become common. This staging system categorizes tumors using the following scale:
- Stage 0 -- Non-invasive tumors that are only in the bladder lining
- Stage I -- Tumor goes through the bladder lining, but does not reach the muscle layer of the bladder
- Stage II -- Tumor goes into the muscle layer of the bladder
- Stage III -- Tumor goes past the muscle layer into tissue surrounding the bladder
- Stage IV -- Tumor has spread to neighboring lymph nodes or to distant sites (metastatic disease)
Bladder cancer spreads by extending into the nearby organs, including the:
- Prostate
- Rectum
- Ureters
- Uterus
- Vagina
It can also spread to lymph nodes in the pelvis, or to other parts of the body, such as:
- Bones
- Liver
- Lungs
