Stage and grade of bladder cancer
The stages for bladder cancer depend on the size of the cancer, its growth in the bladder wall
, any lymph node involvement, and any spread to other areas of the body (metastasis). The grade of bladder cancer refers to how the cancer cells look under a microscope. Stage and grade of bladder cancer has been classified by the American Joint Committee on Cancer (AJCC).1 This classification is also used in Canada.
The primary tumour (T) is staged in the following way:
Superficial bladder cancer
- TX: A primary tumour cannot be assessed.
- T0: No primary tumour seen.
- Ta: Superficial cancer is found only in polyps (papillary) on the surface of the inner lining of the bladder.
- Tis: Carcinoma in situ. Tumour is found only in flat lesions on the surface of the inner lining of the bladder.
- T1: Tumour is found in the connective tissue below the lining of the bladder but has not spread to the bladder muscle.
Invasive bladder cancer
- T2a: Tumour has spread to the inner half of the smooth muscle layer (superficial layer) below the lining of the bladder.
- T2b: Tumour has spread to the outer half of the smooth muscle layer (deep layer) of the bladder.
- T3a: Tumour has spread through the muscular wall of the bladder into the fatty tissue layer as identified under a microscope.
- T3b: Tumour has spread through the muscular wall of the bladder into the fatty tissue layer and a mass is visible to the eye.
- T4a: Tumour has spread to the prostate in men and to the uterus or vagina in women.
- T4b: Tumour has spread to the pelvic or abdominal wall.
After the tumour (T) is staged, the TNM system stages lymph node involvement (N) to help determine the treatment options at each stage. Lymph node involvement is staged in the following way:
- NX: Lymph nodes in the pelvis cannot be assessed.
- N0: No bladder cancer is found in lymph nodes.
- N1: Bladder cancer is found in one lymph node, 2 cm (0.8 in.) or less in size.
- N2: Bladder cancer is found in one lymph node and is more than 2 cm (0.8 in.) but less than 5 cm (2 in.) in size, or cancer is found in multiple lymph nodes but none are more than 5 cm (2 in.) in size.
- N3: Bladder cancer is found in one or more lymph nodes and is more than 5 cm (2 in.) in size.
The last part of staging bladder cancer is to determine whether cancer has spread to other parts of the body (metastasized). The TNM system stages metastasis (M) in the following way:
- MX: Spread of cancer to other organs cannot be evaluated.
- M0: No evidence of bladder cancer exists elsewhere in the body.
- M1: Bladder cancer cells are found somewhere else in the body.
The TNM staging system allows a health professional to recommend the most effective treatment options and discuss the long-term outcome (prognosis) based on the type of tumour, the stage of the cancer, and the person's age and overall health condition.
Classification of bladder cancer Stage TNM Classification 0(a)
TaN0M0
0(is)
TisN0M0
I
T1N0M0
II
T2aN0M0
T2bN0M0
III
T3aN0M0
T3bN0M0
T4aN0M0
IV
T4bN0M0
Any T, N1, M0
Any T, N2, M0
Any T, N3, M0
Any T, any N, M1
The grade of bladder cancer refers to how the cancer cells look under a microscope. Bladder cancer cells are described as well differentiated, moderately differentiated, or poorly differentiated. Differentiation is a term used to describe how clearly the cancer cells can be distinguished from the surrounding normal tissues and how normal or abnormal the cells look.
- GX: Grade cannot be assessed.
- G1: Well-differentiated cancers have very clear boundaries and cells that look relatively normal. They usually do not grow and spread rapidly.
- G2: Moderately differentiated cancer has more abnormal looking cells and cell boundaries.
- G3-4: Poorly differentiated cancers have less-clearly defined boundaries and cells that look very abnormal. They often grow and spread rapidly.
| Author: | Douglas Dana Shannon Erstad, MBA/MPH | Last Updated: July 9, 2007 |
| Medical Review: | Anne C. Poinier, MD - Internal Medicine E. Gregory Thompson, MD - Internal Medicine Philip Belitsky, MD, FRCSC - Urology | |
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