Staging and Grading of Bladder Cancer

What does "staging" mean in regard to bladder cancer?

The stage is defined as the estimation of extent (size and location) of the cancer at the current time. More specifically, it defines how extensive the cancer is within the bladder and if it has spread to tissues around the bladder or to other parts of the body. The studies vary from patient to patient, depending on various factors. The usual initial staging studies include the pathology report from the initial biopsy, the general physical examination and digital rectal examination, and often, a CAT scan of the pelvic area. On occasion, a CAT scan (computerized axial tomography) will be done of the upper abdomen, or an MRI (magnetic resonance imaging) will be done of the pelvic and abdominal areas, along with a chest X-ray. The stage of the cancer is the most important deciding factor in which treatment will be used.

What is the difference between "clinical stage" and "pathological stage"?

The clinical stage is the stage estimated by the physician before any surgery is done. The pathologic stage is the true extent of the cancer as found by the pathologist in the bladder specimen after removal of the bladder and lymph nodes (if that option is performed). One obvious dilemma is the fact that clinical stage and pathological stage do not always agree. That is, the cancer can be more or less extensive than estimated by the pre-operative examinations and tests. If no surgery is done on the bladder or lymph nodes, the clinical stage is the only stage that is obtained.

What staging systems are used?

Two commonly used staging systems exist -- ABCD and TNM. The ABCD is older and gives a broad description of the cancer. The TNM system separately describes the bladder (T), the lymph nodes (N), and evidence of metastatic disease (distant spread) (M). With the ABCD system the cancer is denoted by one letter followed by one number (e.g., A1, B2). With the TNM system the bladder is described by the T, the lymph nodes by the N, and distant spread by the M. Each letter is followed by a describing number (e.g., T2aN0M0). This may be confusing, but you can ask us if you have questions.

Normal Anatomy

Male

Female

MAGNIFICATION of BLADDER LINING

Primary Tumor TX Primary tumor cannot be assessed TO No evidence of primary tumor Ta Non-invasive papillary carcinoma

Tis Carcinoma in situ: "flat tumor"

T1 Tumor invades subepithelial connective tissue

T2 Tumor invades superficial muscle (inner half)

T3 Tumor invades deep muscle or perivesical fat T3a Tumor invades deep muscle (outer half)

T3b Tumor invades perivesical fat i. microscopically ii. macroscopically (extravesical mass)

T4 Tumor invades prostate, uterus, vagina, pelvic wall or abdominal wall

T4a Tumor invades prostate, uterus, and vagina

T4b Tumor invades pelvic wall or abdominal wall

Lymph Node (N)

NX Regional lymph nodes cannot be assessed N0 No regional lymph node metastasis N1 Metastasis in a single lymph node, 2 cm or less in greatest dimension N2 Metastasis in a single lymph node, more than 2 cm but not more than 5 cm in greatest dimension; or multiple lymph nodes, none more than 5 cm in greatest dimension N3 Metastasis in a lymph node more than 5 cm in greatest dimension

Distant Metastasis (M)

MX Presence of distant metastasis cannot be assessed M0 No distant metastasis M1 Distant metastasis

Stage Grouping

  • Oa Ta N0 M0
  • Ois Tis N0 M0
  • I T1 N0 M0
  • II T2 N0 M0
  • T3a N0 M0
  • III T3b N0 M0
  • T4a N0 M0
  • IV T4b N0 M0
  • AnyT N1 M0
  • AnyT N2 M0
  • AnyT N3 M0
  • AnyT AnyN M1

What are the other staging criteria?

Recurrent cancer Recurrent disease means the cancer has come back (recurred) after it has been treated. It may come back in the bladder or in another part of the body.

How do we "grade" bladder cancer?

The grade is defined from the bladder biopsy by the pathologist. The grade gives us an idea of how fast the cancer might be growing or how aggressive it might be. High-grade cancers grow faster and spread earlier than low-grade cancers. The current system of grading uses only three different grades: well differentiated, moderately differentiated, and poorly differentiated (i.e., Grade I, II and III). It is still used in general discussions about cancer. Some pathologists will use a four-level grading system (I, II, III and IV). Either system is acceptable, and the pathologist will always note how many levels he uses by declaring the cancer as a II/III, for example, or II/IV. The denominator (second number) states what system is used. Well-differentiated means the cancer has more resemblance to normal bladder tissue and usually does not grow or spread quickly. Poorly differentiated tumors do not resemble normal bladder tissue and usually grow quickly and spread to other tissues earlier. Moderately differentiated tumors are in the middle range. Grade, while important, has less bearing on the treatment decisions than does the stage. After the grade and stage are known, other factors come into play before a decision can be made about future treatment.

What other tests are used to grade bladder cancer?

Another less commonly used grading test looks at the number of chromosomes in the cancer cells, or "ploidy" (ploy-dee). The test is called "flow cytometry." Normal human cells have 46 chromosomes. This is referred to as "diploid" (dip-ployed), meaning 23 pairs. When flow cytometry is used to count the chromosomes, we discover that some cancers have an extra chromosome and are called "aneuploid" (an-u-ployed). Aneuploid cancers tend to spread more quickly and have a worse prognosis -- but not always. Other tests that look at chromosome abnormalities are being studied in research laboratories around the world. While ploidy and other chromosome tests do give us some information, the stage of one's cancer is still more important in determining treatment options. Just as important, however, are the health, life expectancy and current medical condition of each individual.