The diagnostic investigation begins with a thorough medical history
and a physical examination. The doctor will ask the patient about past
exposure to known causes of bladder cancer, such as cigarette smoke
(either through personal smoking or through "second-hand" smoke) or
chemicals. Also, because
hematuria can come from anywhere in the urinary tract, the doctor typically order
radiological imaging
of the kidneys, ureter and bladder to check for problems in these
organs. In this era, this is most often accomplished by a CT Urogram (CT
scan focused on the urinary tract).
Diagnostic tools to check for bladder cancer include various types of
urinalysis.
In one type, the urine is examined under a microscope to look for
cancer cells that may have been shed into the urine from the bladder
lining (urinary cytology). Urine cytology is analogous to a Pap Smear,
in this case looking for cancer cells that are sloughed off in the
urine. Urine can also be tested for substances known to be closely
associated with cancer cells (tumor markers).
The urologist's most important diagnostic tool is
cystoscopy,
which is a procedure that allows direct viewing of the inside of the
bladder. This is most commonly performed as an office procedure under
local anesthesia or light sedation. First, a topical
anesthetic gel is applied, so the patient will feel little or no discomfort. The doctor then inserts a viewing instrument called a
cystoscope
through the urethra and into the bladder. Looking through the
cystoscope, the doctor is able to examine the bladder's inner surfaces
for signs of cancer. Modern cystoscopes are soft and flexible, and this
procedure is generally well tolerated.
If
tumors are present, the doctor notes their appearance, number, location and size. As removal (
resection)
of the tumors cannot usually be done under local anesthesia, the
patient is then scheduled to return for a surgical procedure to remove
the tumor under
general anesthesia or spinal anesthesia. In a manner as before, the doctor inserts an instrument, called a
resectoscope,
into the bladder. This is a viewing instrument similar to the
cystoscope, but contains a wire loop at the end for removing tissue.
This procedure is done through the urethra and is called a
transurethral resection of bladder tumors. The removed tissue is sent to a pathologist for examination.
Pathologists are specialists who interpret changes in body tissues caused by disease.
In addition to removing visible tumors, the doctor may remove very
small samples of tissue of any suspicious-looking areas of the bladder. A
pathologist also examines this tissue.
If a
biopsy is taken and bladder cancer
is found, the pathologist who examines the tissue will grade the tumor
according to how angry the cells appear. The most widely used grading
systems classify tumors into two main grades: low and high. The cells of
low-grade tumors have minimal abnormalities. In high-grade tumors, the
cells have become disorganized and many abnormalities are apparent. The
grade indicates the tumor's "aggression level"—how fast it is likely to
grow and spread. High-grade tumors are the most aggressive and the most
likely to progress into the muscle.
Staging of bladder cancers is based on how deeply a tumor has
penetrated the bladder wall. Table 1 lists stages of penetration using
the TNM classification system.
|
Table 1 -- Staging of primary bladder cancer tumors (T)
|
|
Ta:
| Noninvasive papillary tumor (confined to urothelium)
|
|
Tis:
| CIS carcinoma (high grade "flat tumor" confined to urothelium)
|
|
T1:
| Tumor invades lamina propria
|
|
T2:
| Tumor invades bladder muscle
|
|
T2a:
| Invades superficial bladder muscle
|
|
T2b:
| Invades deep bladder muscle
|
|
T3:
| Tumor invades perivesical fat
|
|
T3a:
| Microscopic perivesical fat invasion
|
|
T3b:
| Macroscopic perivesical fat invasion (and progressing beyond bladder)
|
|
T4:
| Tumor invades prostate, uterus, vagina, pelvic wall or abdominal wall
|
|
T4a:
| Invades adjacent organs (uterus, ovaries, prostate)
|
|
T4b:
| Invades pelvic wall and/or abdominal wall
|
Stages Ta and Tis (in the
urothelium) and stage T1 (in the
lamina propria)
are the non-muscle-invasive stages. Most Ta tumors are low grade, and
most do not progress to invade the bladder muscle. Stage T1 tumors may
be much more likely to become muscle invasive but many, especially if
not initially deeply invasive of the connective tissue, can be managed
successfully by resection and medications placed in the bladder (see
below). Stage Ta tumors often recur after treatment but they tend to do
so with the same stage and grade. Stage T1 tumors must be watched
carefully for the possibility that they may recur at a higher and
potentially lethal stage.
The Tis stage classification is reserved for a type of high-grade cancer called
carcinoma in situ (
CIS). CIS usually appears through the
cystoscope as a flat, reddish, velvety patch on the bladder lining. It is difficult to remove and is best treated with
immunotherapy or
chemotherapy.
If untreated, CIS will likely progress to muscle-invasive disease. CIS
in the bladder is a serious finding – it is cancer not just a
premalignant lesion.
