So, Dr. Scholz, we know that Gleason score is a vast topic and when it comes to Gleason
7, I've seen a lot of questions coming up about what is Gleason 7? What does it mean?
Can you explain what Gleason 7 is and how it's broken down?
It's referring to the grade and we know that prostate cancer comes in many different genetic
variations. When you look at genetic variations of humans (some are tall, some are short,
some have dark skin, some have light skin) that's because the underlying genetics are
different, and the tumor cells also have varied genetics and some behave more aggressively,
some behave less aggressively, and that shows up in the appearance of the cells under the
microscope. And there are basically three categories that the professional doctors—the
pathologists—assign when they look at these cells. There are categories 3, 4, and 5 (1
and 2 went away many years ago). 3, 4, and 5 are very distinct different types of genetic
prostate cancer, but sometimes there is more than one type in one patient. So you can have
3 and 4 or 4 and 3, so the convention is to report both the types if two types are seen,
and then to put the more common type (the more prolific type) that was seen under the
microscope as the number in first place and then the second number, the less common type,
in the second place. And so you have something like a 3+4 or a 4+3.
So, this is actually the type of cancer that's within the prostate?
Precisely, yes. So this is removed with a needle biopsy and then sent off for preparation
and looked at by doctors who are trained only to look at stuff under microscopes. They're
called pathologists.
So, once the pathologist is done, he sends the report back to the urologist and the patient
gets that report back and has a discussion with their urologist. Do you think that urologists
are explaining all the nuances of Gleason to the patient? Usually, I don't see that
happening. I think that patients kind of get this report and then they kind of come to
us to have it explained. What would you want a patient to know when they get back maybe
a 3+4 or a 4+3 on a report? What are the nuances that they should pay attention to?
Well, it's a complex field. I think, you know, the overriding issue with prostate cancer
is to first realize that it's different from all the different cancer. It doesn't matter
if it's a 3+4 or 4+3, the chances of actually dying from it is very very small. So, for
the most part, we're looking at how can we get by with the least amount of treatment
so that we don't cause long term problems with urinary function and sexual function
and still cure the condition. So, the refinements of 3+4 versus 4+3, then, impact how much and
what kind of treatment you use because a 4+3 (the 4 being a higher grade, being a type
of prostate cancer that has a somewhat greater propensity for spreading) is going to require
more thorough treatment to make sure you get it whereas the 3+4 (3 being a lower grade)
less of a concern and can be treated with less aggressive treatment.
Does it matter where these different tumors are in the prostate? Or is the grade just
the most important part when it comes to deciding treatment?
Multiple things matter like if you look at basketball players, how well they shoot, how
well they jump, how quick they run, how smart they are, do they pass well. All of these
things are components of a good basketball player. I don't know what the number one thing
is in a basketball player, but in prostate cancer, the number one thing is the grade
because we're always most concerned about the possibility of spread. But other factors
like how big is the tumor, is it coming out the edge of the gland or in the seminal vesicles,
those are important too. Just like there are multiple factors in a good basketball player,
there are multiple factors in determining how risky a specific cancer is.
So, do you use imaging to determine those factors?
Yes, modern imaging has revolutionized prostate cancer now. Multiparametric MRIs (we use color-doppler
ultrasounds) enable us to see where the tumor is, how big it is, and also determine if there's
more than one tumor, is it coming out the side of the gland, all of those factors (as
one would imagine) are very important in assessing how risky it is.
So, when it comes to the size of the tumors, how much does that matter in regard to deciding
on a type of treatment?
So, the size is relevant. How extensive it is throughout the gland is somewhat related
to the size. If you take a really big prostate where a larger tumor isn't like taking over
the whole gland, a bigger tumor versus a smaller tumor is not going to have that much importance.
The grade of the tumor will be a far more important outcome determinant than the size
is, but it certainly is important if someone has a smaller prostate and the tumor is large.
Obviously, focal treatment is not going to be much of a possibility for those individuals.
There's a possibility with larger tumors that are randomly biopsied isn't necessarily representative
because we've got a lot of cancer but you only take a couple of biopsies, each core
is only a millimeter across, so are you missing higher grade disease? So, a larger tumor does
raise some questions about the possibility of higher grade disease lurking in a corner,
but it hasn't proven to be as an important predictor as other things like the Gleason
score itself and so some men with Gleason 6 tumors that are large just have their disease
sit there year after year—it doesn't cause any harm. So, just being large alone is not
necessarily really a serious problem, but it does raise some questions about could there
be some higher-grade disease that was missed because biopsies are only taking a sample
and maybe some section of the tumor is harboring a little higher grade disease that has been
missed, and that, of course, is why people need to be watched closely when they're on
active surveillance, but it hasn't proven to be as big an issue as one might think.
How do you know whether the size of the tumor, how do you know if it is big or small?
Well, the most indirect way, of course, is if the PSA is high. Sometimes people think
that may equate with a bigger tumor. Doctors can do a digital rectal finger exam and sometimes
they can feel a nodule, and if that's the case they can judge how large it is, but more
commonly when men are undergoing random biopsies when they do these grid patterns you can see
how if one or two cores have cancer in them versus 8 cores, that's going to equate with
a larger tumor. And now, of course, with these MRI scans, color-dopplers, PSMA/PET scans,
the scans can literally show how large the cancer is on the scan itself.
Thanks for watching! If you would like more information about the topics we discussed
today you can go ahead and visit our website at PCRI.ORG. Don't forget to subscribe to
our YouTube channel. We come out with new videos every single week.