Muscle-Invasive Stages of Bladder Cancer

When a patient is diagnosed with bladder cancer, healthcare professionals use a combination of information from diagnostic tests, and possibly surgery, to determine the patient’s overall bladder cancer stage.^1,2 This is done using combined information about the bladder tumor (T), whether there are cancer cells in lymph nodes (N) close to the bladder, and whether the cancer cells have metastasized (M), or spread, to any parts of the body distant from the bladder.

A number and/or letter is assigned to each staging category of T, N, and M. This is used to help healthcare providers recommend the best treatment options for a patient’s specific kind of bladder cancer. There are five overall stages of bladder cancer: stage 0, stage 1, stage 2, stage 3, and stage 4.

Bladder cancer typically starts to grow in the inner lining of the bladder, called the urothelium. In some patients, the cancer can grow into and through the muscle of the bladder wall.

Stage 2 bladder cancer

A diagnosis of stage 2 bladder cancer means that the bladder cancer cells have grown into the muscle layer of the bladder wall.^1,2 This is also called muscle-invasive bladder cancer. Stage 2 bladder cancer includes the following combined TNM stages:

• [T2a, N0, M0]
• [T2b, N0, M0]

In both of those types of stage 2 bladder cancer, the cancer cells have not grown into the nearby lymph nodes (N0) and they have not spread to other parts of the body. The muscle portion of the bladder wall has two layers. The inner half, closest to the bladder lining, is called the superficial muscle. The outer half is also called the deep muscle of the bladder. If the tumor is type T2a, it means that the cancer cells have spread into the superficial muscle, but not into the deep muscle. If the tumor is type T2b, the bladder cancer cells have grown through the superficial muscle and into the deep muscle of the bladder. However, the cancer cells have not yet spread into the layer of fatty tissue that surrounds the outer part of the bladder muscle.

Stage 3 bladder cancer

Stage 3 bladder cancer means that the cancer cells have spread beyond the bladder muscle.^1,2,3 Stage 3 bladder cancer includes the following combined TNM stages:

• [T3a, N0, M0]
• [T3b, N0, M0]
• [T4a, N0, M0]

In all three types of stage 3 bladder cancer, the cancer cells have not spread to the lymph nodes near the bladder (N0) and they have not spread to other parts of the body.

In a bladder tumor that is stage T3a or stage T3b, the bladder cancer cells have grown into the layer of fatty tissue that surrounds the outside of the bladder. This layer of fatty tissue is called perivesical tissue.

In a stage T3a bladder tumor, the bladder cancer cells in the perivesical tissue are only visible through a microscope. In a stage T3b bladder tumor, the bladder cancer cells have grown into the perivesical tissue and are large enough that they are visible using an imaging test or they can be felt by a healthcare professional. A stage T4a bladder tumor is different in women and men. In women, the stage T4a tumor has grown through the perivesical tissue and into the uterus and/or vagina. In men, the stage T4a tumor has grown through the perivesical tissue and into the prostate. However, in both women and men, a stage T4a tumor has not grown into the pelvic wall or the abdominal wall.

Treatment options for muscle-invasive bladder cancer

If you are diagnosed with stage 2 or stage 3 bladder cancer, your healthcare team will discuss the best possible treatment options available to you.³

Partial or radical cystectomy

Some people with stage 2 or stage 3 bladder cancer will need to undergo surgery to remove part of the bladder (called a partial cystectomy) or surgery to remove the entire bladder (called a radical cystectomy). If you need to have a radical cystectomy, the surgeon will often create another way for urine to be stored and removed from the body. Some people who have a radical or partial cystectomy may also have chemotherapy treatment.

TURBT, radiation, and chemotherapy

Other patients may have another type of procedure called a transurethral resection of bladder tumor (TURBT), in which the bladder tumor(s) are removed from the bladder lining. The surgeon may use a procedure called fulguration to try to eliminate cancer cells that remain after the tumor is removed. Another treatment option for some patients is external radiation therapy with or without chemotherapy treatment. Some patients may choose to take part in a clinical trial to investigate a new type of treatment for bladder cancer.

Survival rates for localized bladder cancer

In the United States, the average five-year survival rate for people diagnosed with localized bladder cancer (cancer that has not spread outside the bladder) is about 70%, which means that around 70 out of 100 people are alive five years after they were first diagnosed.⁴