Bladder cancer is staged based on the extent of tumour invasion into the bladder wall and whether it has spread to nearby lymph nodes or other organs. The TNM classification is used to stage bladder cancer.  Doctors use the results from diagnostic tests and scans to answer the following questions:

• Tumour (T):How large is the primary tumour? Where is it located?
• Node (N):Has the tumour spread to the lymph nodes? If so, where and how many?
• Metastasis (M):Has the cancer spread to other parts of the body? If so, where and how much?

• TX: The primary tumour cannot be evaluated.
• T 0 (T zero): There is no evidence of a primary tumour in the bladder.
• Ta: This refers to non-invasive papillary carcinoma. This type of growth often is found on a small section of tissue that easily can be removed with a transurethral resection of bladder tumour (TURBT).
• Tis: This stage is carcinoma in situ (CIS) or a “flat tumour.” This means that the cancer is only found on or near the surface of the bladder. The doctor may also call it non-muscle-invasive bladder cancer, superficial bladder cancer, or non-invasive flat carcinoma. This type of bladder cancer often comes back after treatment, usually as another non-invasive cancer in the bladder.
• T1: The tumour has spread to the connective tissue (called the lamina propria) that separates the lining of the bladder from the muscles beneath, but it does not involve the bladder wall muscle.
• T2: The tumour has spread to the muscle of the bladder wall.
  • T2a: The tumour has spread to the inner half of the muscle of the bladder wall, which may be called the superficial muscle.
  • T2b: The tumour has spread to the deep muscle of the bladder (the outer half of the muscle).
• T3: The tumour has grown into the perivesical tissue (the fatty tissue that surrounds the bladder).
  • T3a: The tumour has grown into the perivesical tissue, as seen through a microscope.
  • T3b: The tumour has grown into the perivesical tissue macroscopically. This means that the tumour(s) is large enough to be seen during imaging tests or to be seen or felt by the doctor.
• T4: The tumour has spread to any of the following: the abdominal wall, the pelvic wall, the prostate or seminal vesicle (the tubes that carry semen), or the uterus or vagina.
  • T4a: The tumour has spread to the prostate, seminal vesicles, uterus, or vagina. Surgical removal of the tumour may still be possible in this stage.
  • T4b: The tumour has spread to the pelvic wall or the abdominal wall. Surgical removal of the tumour may not be possible in this stage.

• NX: The regional lymph nodes cannot be evaluated.
• N0 (N zero): The cancer has not spread to the regional lymph nodes.
• N1: The cancer has spread to 1 regional lymph node in the pelvis.
• N2: The cancer has spread to 2 or more regional lymph nodes in the pelvis.
• N3: The cancer has spread to the common iliac lymph nodes, which are located behind the major arteries in the pelvis, above the bladder.

M0 (M zero): The disease has not metastasised.

M1: There is metastasis.

• M1a: The cancer has spread only to lymph nodes outside of the pelvis.
• M1b: The cancer has spread other parts of the body.

Staging is crucial for several reasons:

1. Treatment Planning:
   • Guides the selection of appropriate treatments, including surgery, chemotherapy, immunotherapy, or radiation.
2. Prognosis:
   • Provides information about the likely course of the disease and the expected outcomes of treatment.
3. Clinical Trials:
   • Eligibility for participation in clinical trials may be influenced by the stage of bladder cancer.

Staging helps determine the extent of cancer spread and guides treatment decisions. Stages range from 0 (early, non-invasive) to IV (advanced and invasive).

Treatment plans for bladder cancer are tailored based on the stage and characteristics of the cancer. Options may include:

• Surgery: Removal of the cancerous tissue, including transurethral resection, partial or radical cystectomy.
• Intravesical Therapy: Administration of medication directly into the bladder.
• Chemotherapy: Using drugs to kill cancer cells or prevent their growth.
• Radiation Therapy: Using high-energy rays to target and destroy cancer cells.
• Immunotherapy: Boosting the body's immune system to target and destroy cancer cells.