Hi, I’m Dr. Scholz. Let’s talk about prostate cancer.
In these videos, we’ve been going through a series on the Teal stage of prostate cancer
otherwise known as intermediate risk. Intermediate risk or Teal carries a very broad spectrum
even though it’s only one of the five stages. Teal is broken down into Low, Basic, and High.
And today’s video is covering what we call combination therapy. Combination therapy for
prostate cancer consists of three things for Teal: a seed implant, testosterone inactivating
pharmaceuticals (otherwise known as androgen deprivation or testosterone blockade. The
short acronym is TIP), and IMRT which stands for intensity modulating radiation. These
things are given together when you give combination therapy for Teal. Combination therapy is reserved
for High-Teal, and you can go to the PCRI staging guide to figure out whether you are
in the Basic or High category. For men that are in the Basic simply one form of therapy
(a seed implant, IMRT, surgery, hormone therapy) is sufficient, but when you get into the High-Teal
combination therapy is needed to obtain optimal cure rates.
So let’s just talk briefly about therapy for High-Teal or combination therapy which
is the generally recommended type of treatment. The seed implant is the backbone. Radioactive
seeds come in temporary and permanent, and they are both effective, and they deliver
the lion’s share--perhaps 2/3 of the radiation. IMRT is then often given in addition. It’s
interesting that in 2019 there is debate about whether all men with High-Teal really do need
IMRT. If someone needs radiation to the pelvic lymph nodes in addition to the prostate which
of course is standard, then certainly you need IMRT. How do you know if you need IMRT
to the lymph nodes? Well, there’s a formula for calculating the percentage likelihood
of having cancer spread into the lymph nodes; it is called the “Yale formula.” Y-A-L-E.
The Yale formula, you can just Google it and it will come up and there’s a calculator
right there and you’ll put in your PSA and your Gleason, and that will tell you what
the percentage likelihood of lymph node involvement is. If lymph nodes are more than 15% likely
to be involved with prostate cancer, IMRT to the lymph nodes is certainly necessary
and you can’t talk about jettisoning the IMRT, you must do a combination.
Let’s move on and talk about the hormone portion or the TIP of this combination therapy.
IMRT in multiple studies, when used as a standalone treatment, has been shown to require the addition
of at least four months of TIP to obtain optimal cure rates. The usual sequence is a couple
of months of testosterone blockade and then the radiation starts (you can either go with
a seed implant first or IMRT first); the hormone therapy continues through the radiation and
then comes to an end when the radiation finishes. So the TIP portion should always be given
in conjunction with IMRT. If the risk of lymph node involvement is less than 15% according
to the Yale formula, and your physicians are talking about the possibility of getting away
with just a seed implant for High-Teal, then you can consider forgoing or skipping the
TIP as well.
The bottom line then for combination therapy then is that it is reserved for men who are
High-Teal, and in the men who are High-Teal that have more than a 15% chance of lymph
node involvement they should get IMRT and TIP in combination with a seed implant. The
men that are in High-Teal that have less than a 15% chance of lymph node involvement some
experts believe that a seed implant alone might be sufficient. This is a debatable new
area, and if you want to default to the standard agreed upon consensus approach, you’re going
to use combination therapy for all types of High-Teal even those with less than a 15%
chance of lymph node involvement. So the men who decide to try to get by with less treatment,
they’re going to have to have discussions with their physicians about whether or not
to do combination therapy in High-Teal. So to be clear for the next stage up (we call
it Azure or high-risk prostate cancer), all men get combination therapy under all circumstances,
but for High-Teal this is sort of a transition and probably the majority of men are indeed
going to get combination therapy with a seed implant, IMRT, and 4-6 months (but usually
four months) of testosterone inactivating pharmaceuticals.