So, the next question we have is about an advanced patient, and I guess the doctor
wants to put him on Xgeva. He wants to know would you just put him on Xgeva. Obviously, we don't
know the case history of it, but how effective have you seen Xgeva in advanced prostate cancer?
So Xgeva is FDA-approved for men that have bone metastases. It's been shown to cut the risk of
bone-related complications from cancer when men are given Xgeva. There's also one study showing
that in men who have prostate cancer that get Xgeva that it will delay the growth of cancer
in the bone to some degree, not dramatically, but to a measurable degree. Offsetting all
those positives there is an issue related to something called osteonecrosis where there's
damage to the jaw caused by large doses of these medications given over a prolonged period of time.
So, there's probably a happy medium. The Xgeva is FDA-approved for monthly administration
and that dose might be a little high. It seems that the incidence of osteonecrosis is
fairly frequent when full doses are used for prolonged periods of time,
and so — but we do know that there are benefits from these medicines. So some sort of
compromise, maybe treatment administered every three months every six months seems to be a nice
in-between ground to consider to balance out the risks and the benefits of Xgeva.
What would the PSA monitoring look like for that?
So, Xgeva to my knowledge doesn't have any impact on PSA. It does strengthen the bones
like some other medicines that are available for treating osteoporosis. Xgeva helps bring more
calcium into the bones and fortifies them, but it doesn't lower PSA or raise PSA for that matter.
So the next question we have is which side effects of ADT are more prevalent for
different durations of treatment? And ADT being androgen deprivation therapy or hormone therapy.
So are there side effects that are more prevalent in the six-month dose versus the 24-month dose?
Right, so intermediate-risk patients get six months of testosterone deprivation, and high-risk
patients, Gleason 9's [and] 10's, PSA's over 20 get 18 months of testosterone deprivation.
The cumulative effect of low testosterone probably is most pronounced in muscle loss and weight gain.
Those are the most prominent issues and
we've emphasized over and over that men need to do a resistance training program [and] be
on a careful diet while they have low testosterone to offset those problems.
I know I was talking to a couple patients recently and I had heard a similar
storyline that they were on hormone therapy for about six months and they never experienced any
hot flashes or anything of that sort. They did experience the fatigue. So is that normal that
you see patients who are on the six-month version of hormone therapy not have as many
symptoms as far as hot flashes and things like that go, or is that just dependent on the person?
Completely dependent on the person. People could have hot flashes,
you know, within three or four weeks of starting treatment, or they may not get them at all.
So this person says that their dad was diagnosed with prostate cancer and they did find bone mets,
and that they started him on Xtandi and Orgovyx, which was recently approved.
They said that their dad's PSA was 94 and then 200 one week before —— it spiked to 200 one week
before he started these medications. This person would like to know why wasn't chemo or surgery
an option for their father and why did they just put him on these medications instead?
Well, that's a very broad question. There are certainly situations where Taxotere
chemotherapy would be a logical consideration. The studies so far haven't looked at the combination
of Xtandi plus Orgovyx or Lupron plus chemotherapy, so the benefits of chemotherapy
in this situation are theoretical, and I think the theoretical foundation is pretty strong but
there are no studies yet proving that you should do Taxotere in that situation. The other aspect
of the question about giving radiation that is — there are two types of radiation. One would
be to try and radiate any spots of cancer and that might be a consideration if there were just two or
three spots, but when people have multiple spots around their body it's not practical to radiate
all those spots. But another area of research is to radiate the main tumor in the prostate and
there are some preliminary studies suggesting that that might be advantageous; [it's] controversial,
however. So these are sensible questions and this individual might want to get a second
opinion and talk to some different experts about the feasibility of some of these things, but there
are certainly situations where the Xtandi plus the Orgovyx alone would be quite appropriate.
So this person is asking that, you know, they — a lot of people believe that testosterone
feeds cancer, and so they're wondering why younger men who have higher testosterone,
you know, in their bodies don't you know get it younger or die sooner because of it?
Right, that is actually somewhat of a fallacy. While removal of testosterone
can cause prostate cancer to regress; the presence of testosterone in normal males is not the cause
of prostate cancer. The cause of prostate cancer is uncertain; it may have to do with inflammation,
it may have to do with genetic predispositions, or other factors that we're not clear about,
but the idea that testosterone is causing the cancer is incorrect. So,
the best analogy I've come up with—and it may not be a very good one—is the way we
all need oxygen to exist, but if you give us more oxygen we don't live longer, we don't live more
vibrantly, we continue to exist, but if you take our oxygen away, we die.
So, prostate cancer cells depend on testosterone just the way we depend on oxygen to live,
but having oxygen did not create our life or cause our life. Oxygen is necessary to exist,
but it doesn't engender life itself, neither does testosterone generate cancer.
Hi everyone, it's Alex and Hunter. Hunter's our official PCRI mascot. If you'd like to learn
more about men's health tips and prostate cancer, you can follow him on Instagram,
SirHuntertheDal, and also subscribe to our YouTube
channel; we come up with new prostate cancer videos every week. Say "bye!"