If you're looking for information about prostate cancer for yourself or for someone you love,
you're going to encounter the Gleason Score. Okay, so what is it?
At its simplest, the Gleason Score is a measure of how aggressive or non-aggressive a prostate
cancer tumor is.
How is the score derived? Again, a simple answer. A medical professional, a pathologist,
visually examines a biopsy sample under a microscope and makes a judgment based on what
he or she sees there. We'll come back to biopsies in a couple of minutes, so stick around.
The biopsy sample, called a core, is removed from the prostate using a hollow needle. The
pathologist examines the score and assigns scores from one to five based on how disorganized,
irregular, and, well, just how messy things look. A good general definition of cancer
is an abnormal growth of cells which tend to proliferate in an uncontrolled way, and
that's exactly what the pathologist is looking for—abnormal growth and uncontrolled proliferation.
A Gleason 1 looks pretty much like the normal prostate glands and it represents a very slow-growing
non-aggressive form of the cancer—almost a non-cancer. A [Gleason] 2 shows a little
bit more space between the glands and a little irregularity, but still, it's very slow-growing.
Here's what a 3 looks like. It's an intermediate form of the cancer, but still not very aggressive.
Now 4. And now 5. These last two represent the most aggressive form of the cancer.
So the pathologist examines the core and a assigns a score to any cancer he or she sees.
Typically, there are two scores per core. The first or primary score represents the
most prevalent form of cancer, and the second, the less prevalent form. That's why you'll
hear or read things like Gleason 6 "3+3," or Gleason 9 "4+5." Here's where it gets a
little tricky. A Gleason 7 does not always equal a Gleason 7. The order of the two scores
is important. A 4+3=7 can be very different than a 3+4=7. The first, the 4+3 is likely
to require fairly dramatic treatment because the cancer cells graded 4 are most prevalent.
The 3+4=7 might be best handled with ongoing observation, what we call "active surveillance,"
because less aggressive cancer is most prevalent.
In general, a Gleason score of 6 or less, or a 3+4=7 are going to require active surveillance.
A 4+3=7 and scores above 8 are going to require some form of hormone therapy, radiation, surgery,
or chemotherapy.
So that's the Gleason score, not that complicated. What we have to turn to now is the biopsy,
and how it came to happen in the first place. Up until recently, here was the typical sequence
of events. A man would get a result from his yearly PSA test that was higher than usual.
Typically, that would mean a number of 4 or greater. His GP would refer him to a urologist
who would almost immediately perform a random needle biopsy which entails removing 12 cores
from the prostate. These cores would be sent to the pathologist who would examine them
as we described earlier. There's a real problem here. Using this sequence, an estimated 80%
of men get biopsies that they don't need and 3% of those suffer infections serious enough
to require hospitalization, not to mention other side effects like erectile dysfunction.
Oh yeah, one more thing. Random needle biopsies are not terribly accurate. They can miss serious
cancers.
Thankfully, things have changed and nobody needs to be railroaded into the random needle
biopsy. If you or your loved one has a high PSA number, here's a better sequence.
First, get a second PSA test. Labs can make mistakes and PSA can be elevated for reasons
other than cancer. Things like sexual activity and even riding a bike. If the PSA number
is still high, you have options to see if a biopsy is a good idea.
First, an MRI. Recent advances in MRI imaging have changed everything. The latest generation
of MRI machines called "3 Tesla" or "3T machines" enable radiologists to see all but the tiniest
tumors. The tumors that they can't see almost certainly don't matter. You can find a lost
of MRI centers that do multiparametric testing using a 3T scanner on PCRI.org.
The second option is a new blood test called the 4K test that can accurately estimate whether
you have an aggressive form of the cancer. You can read about the test further at PCRI.org.
If the test indicates that you may have an aggressive form of the cancer, then you want
to move to the MRI. What improvements in MRI imaging means is that biopsies, when they
are needed, can be targeted right to the suspicious area in the prostate. No more random poking.
Be warned though, many doctors are still following the old sequence that involves the random
needle biopsy. Exercise your options. You may have to look for a more forward-thinking
doctor, but avoiding the risks is worth the trouble.
Finally, even if all the tests show that you or your loved one has a more aggressive prostate
cancer, always remember that in the vast majority of cases even an aggressive cancer is slow-growing
and you have time. Take a deep breath; do your research; understand the side effects
and implications of any treatment that you may undergo.
PCRI is a great resource for you. Explore the site. If you can't find the answers you
need, call the helpline. It's staffed by very knowledgable people, most of whom are prostate
cancer survivors. They've been where you are; they know what you're going through. It's
your health, take control of it.