Bladder cancer stages reveal how much and how far the cancer has spread throughout the body. When a patient is diagnosed with bladder cancer, a doctor will perform several tests to determine the stage of the cancer. The stage helps doctors and other healthcare professionals decide on the best course of treatment for a particular patient and helps them determine a prognosis, or probable outcome, for the patient. The stages are numbered 0 through IV. Patients who have bladder cancer are often periodically reassessed during their treatments to determine if the stage has progressed.
To determine the different bladder cancer stages, doctors look at three primary areas — tumors (T), lymph nodes (N) and metastasis (M) — in what is often referred to as the TNM system. Tests and examinations can show how far the tumor is rooted into the lining of the bladder and how large the tumor is. The further the tumor has spread and the larger it is, the higher the stage for the "T" portion of the system.
The lymph nodes are part of the body's immune system and work to help the body fight against infection. Higher stages of bladder cancer indicate that the cancer cells have spread to the lymph nodes around the bladder. Cancer that has progressed to the lymph nodes is often more difficult to treat.
Metastatic bladder cancer is cancer that has spread to other parts of the body. Bladder cancer stages with higher numbers indicate that the abnormal cells have migrated to other parts of the body, such as the lungs, bones or other organs. A number is assigned to the "M" portion of the TNM system based on whether this has occurred. After a doctor has determined values for the "T," "N" and "M" portions of the system, he or she can assign an overall number that represents the bladder cancer stage.
Patients who have bladder cancer stages labeled 0 or I usually have a favorable outlook, and treatment is often successful for these patients. Stage 0 means that the patient has abnormal cells in the bladder lining, but they have not yet progressed to other areas of the bladder. Bladder cancer labeled as Stage I refers to cancer that has grown into the soft tissues around the bladder lining but has not spread to other areas of the body or the lymph nodes.
Stage II bladder cancer refers to bladder cancer that has penetrated the muscular portion of the bladder. The lymph nodes are not affected by Stage II cancer. Patients diagnosed with Stage III bladder cancer might need different treatments. At this point, the cancer has spread into the fatty tissue that surrounds the bladder, and abnormal cells might also be found in the prostate or uterus.
Cancer patients diagnosed with Stage IV bladder cancer have the most serious form of cancer. Aggressive treatment is often needed for these patients. By the time the cancer has progressed to Stage IV, the cancer has spread beyond the bladder into the abdomen or pelvis and might also have spread to the lymph nodes and other organs.