What are the definitions of the stages of prostate cancer?
Stage A
Prostate cancer at this stage cannot be felt and has no symptoms. The cancer is only in the prostate and is
unsuspected. This stage of cancer is found when surgery is done for other reasons, such as for BPH (benign
prostatic hyperplasia). All of these cancers are N0M0, meaning no extension of cancer or positive lymph nodes
are suspected.
Stage A1 or T1a
This cancer is not suspected by the urologist but can be found by the pathologist on prostate tissue removed for
what was thought to be benign prostate enlargement. These cancers involve less than 5 percent of the prostate
tissue removed (commonly referred to as "focal"). Usually, the cancer cells found are low-grade (discussed below).
Stage A2 or T1b
This cancer is not suspected by the urologist but can be found by the pathologist on prostate tissue removed for what
was thought to be benign prostate enlargement. These cancers involve more than 5 percent of the prostate tissue
removed. The cancer cells found are either low or high grade (discussed below).
Stage B
The cancer is limited to the prostate alone. That is, the cancer has not extended, grown or spread outside the
prostate. All these cancers are N0M0, meaning no extension of cancer or positive lymph nodes are suspected.
Stage B0 or T1c
Tumor is not felt on rectal examination. Biopsy is done only because of elevated PSA.
Stage B1 or T2a
The cancer can be felt on rectal examination but involves only one side of the prostate and is less than
1.5 cm (3/5 of one inch) in size.
Stage B1 or T2b
The cancer involves more than half of one lobe, but not both lobes of prostate.
Stage B2 or T2c
The cancer involves both sides of the prostate.
Stage C or T3/4
Cancer cells have spread outside the covering (capsule) of the prostate to tissues around the prostate.
The other glands that produce semen (seminal vesicles) may have cancer in them. All of these cancers are
N0M0, meaning no extension of cancer or positive lymph nodes are suspected.
Stage C1 or T3a
Cancer extends beyond prostate capsule on one side only.
Stage C1 or T3b
Cancer extends beyond prostate capsule on both sides.
Stage C2 or T3c
Cancer extends into one or both seminal vesicles (gland nearby prostate).
Stage C2 or T4a
Cancer extends into bladder or rectum or sphincter (muscles that give urinary control).
Stage C2 or T4b
Cancer extends into other pelvic structures, such as the muscles of the pelvic floor.
Stage C Cancers
A denotes extension beyond capsule (C1/T3a if on one side, C1/T3b if on both sides)
B denotes bladder neck involvement (C2 or T4a)
C denotes seminal vesicle involvement (C2 or T3c)
D denotes sphincter involvement (C2 or T4a)
Stage D or N greater than 0 or M greater than 0
Cancer cells have spread (metastasized) to lymph nodes or to organs and tissues far away from the prostate.
N0 mean no lymph node spread or metastases. M0 means no spread to other areas of body away from the prostate.
Stage D1 or N1
Spread to a single pelvic lymph node, less than 2 cm (4/5 of inch) in greatest dimension.
Stage D1 or N2
Spread to a single pelvic lymph node, more than 2 cm (4/5 of inch) but less than 5 cm (two inches) in greatest
dimension, or to multiple lymph nodes all less than 5 cm.
Stage D1 or N3
Spread to any pelvic lymph node, greater than 5 cm (two inches) in greatest dimension.
Stage D2 or M1
Cancer cells have spread to lymph nodes far from the prostate or to any other parts of the body outside the
pelvic region, such as the bone, liver or lungs.
Recurrent cancer
Recurrent disease means that the cancer has come back (recurred) after it has been treated. It may come back in
the prostate or in another part of the body.
Top Back
Are there any other methods for determining staging?
PSA (prostate specific antigen) has gained widespread use in the detection and monitoring of prostate cancer.
Although PSA levels can be suggestive of tumor volume and stage, specific values for determining stage does not
exist. Guidelines that are often followed suggest that most prostate cancers are confined to the prostate if the
PSA is less than 10 ug/ml, particularly if the Gleason grade is less than 7. PSA values greater than 20 are
associated with an increased risk of high stage disease.
Transrectal ultrasound and computerized axial tomography (CAT scan) is generally thought to be insufficiently
accurate for pre-treatment staging of prostate cancer. Magnetic resonance imaging (MRI) of the prostate gland
has shown increased staging accuracy since the introduction of a special probe called the "endorectal coil."
Its use is still considered investigational and is not used extensively at this point. Its accuracy (or sensitivity)
is in the range of 70-75 percent. MRI of the spine, however, is widely accepted as a tool to confirm the presence of
cancer in bones that are suspicious on bone scan.
Top Back
What does "grading" mean in reference to prostate cancer?
The "grade" is defined by the pathologist from the prostate biopsy. 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.
Top Back
How is the "grade" determined?
Today, cancer specialists usually use the Gleason grading system, named after a pathologist, Dr. Gleason, from
the University of Minnesota. Dr. Gleason's system involves looking for different patterns of aggressiveness
within the prostate and then giving two scores of 1 to 5. These two scores are added to give the total
Gleason score, which will range from 2 to 10. The higher the score, the more aggressive the tumor will be.
For example, a typical Gleason graded cancer might be written as Gleason 4+3 = 7, or Gleason 2+2 = 4. Rarely,
only one score will be used in some medical reports and this can be confusing. To get the true total Gleason
score in these instances, the number needs to be doubled.
The older system of grading used only three different grades: well differentiated, moderately differentiated,
and poorly differentiated. It is still used in general discussions about cancer.
Well-differentiated meant the cancer had more resemblance to normal prostate tissue and therefore usually did
not grow or spread quickly. Poorly differentiated tumors did not resemble normal prostate tissue and usually
grew quickly and spread to other tissues earlier. Moderately differentiated were in the middle.
To compare systems we say that:
Gleason 2, 3, and 4 are well differentiated
Gleason 5, 6, and 7 are moderately differentiated
Gleason 8, 9 and 10 are poorly differentiated.
Grade, while important, has less bearing on the treatment decisions than the stage. After the grade and
stage are known, other factors also come into play before making any decision about future treatment.
Top Back
Are there any other methods for determining "grade"?
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). Anueploid
cancers tend to spread more quickly and have a worse prognosis -- but not always. Other tests looking 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 each individual's health, life
expectancy and current medical condition.
Top Back
What's
New