So, Dr. Scholz, today we want to talk about prostate cancer bone metastases and I understand
that this is a really scary word to a lot of patients, but I think in you practice and
just from talking to you and my experience at PCRI, we've seen a lot of really incredible
stories of people having their bone mets disappear with certain medication. So, first off, when
do bone metastases normally occur in the prostate cancer timeframe?
Well, if people do the, you know, the proper thing and get their PSA tested and catch prostate
cancer when it's still localized, it's very unusual to see bone metastasis in less than
10-20 years. Modern treatment will put people into remission and then hormone therapy will
keep the disease in check for 10-15 years. So, bone metastases are something in the real
distant future and thankfully only in a small percentage of people. Most people end up being
cured if they're diagnosed at an early stage. So, bone metastases in men that haven't been
screening, you know, start to occur if the PSA goes above 20 or 30,—although there
are exceptions to every rule—and become much more common when the PSA gets up in the
hundreds.
So, in this new phase of technology when it comes to imaging and prostate cancer, what
is the best way to detect bone metastases in prostate?
Yeah, right now there's research being done with PSMA PET scans and these are—I've been
describing them as the biggest breakthrough since PSA and far more accurate, very specific,
only for prostate cancer, and so, if people can get access to that type of scan, it really
beats everything else. In the past, we'd have to do a bone scan to look at the bones like
we're talking about, and then a CAT scan to look for any enlarged lymph nodes or an MRI
to look for enlarged lymph nodes.
And when it comes to PSMA, I mean, they can go to our website and look at different clinical
trial centers because it's not FDA-approved yet, but your experience has been—what type
of experience have you seen with those PSMA scans? How small are the tumors that they're
detecting?
Right, so if you're looking at bone scans and CAT scans, you need something—a tumor—maybe
a half-inch across. PSMA PET scans can pick up things that are an eighth of an inch across,
so they are detecting things so much earlier and at a time when they're going to be easier
to treat.
What types of treatments are best when it comes to bone metastases?
Well, with bone metastases we're talking about prostate cancer having become a life-threatening
illness. A lot of prostate cancer is not life-threatening and a minimal, even a monitoring approach
is a perfectly fine way to treat it, but once the disease has waved a flag and said, "I
can spread, I can get in the bones," then we're talking about something that is potentially
life-threatening, and that usually means a combination of available therapies. Systemic
therapies with first and second-generation hormones, maybe even a short course of chemotherapy.
And then, radiation treatment directed to all sites of the metastatic disease. So you
want to basically use every available treatment to eradicate the disease as thoroughly as
possible.
In those different combinations, are there more side effects when you're doing hormone
and chemo together versus others? Like, is there a particular protocol that you would
suggest?
There does tend to be more side effects because if you look at radiation, chemotherapy, hormone
treatment, they all have one common denominator and that is that they can cause fatigue, and
fatigue can become cumulative when you add more and more treatments on. If the patients
are proactive and, you know, go on a very strong exercise program to keep their muscle
mass up, they do pretty well even with combinations of treatment. If they're unwilling to exercise,
it can become very very debilitating.
Where do the bone mets normally go in the body? I know a lot of people when they see
bone metastases sometimes there's multiple cancers involves. They're trying to figure
out which ones prostate, which one is not, so where do these normally travel to?
The most common site of spread is closer to the prostate in the pelvic bones. Second most
common site would probably be the backbone, and whenever we're talking about bone metastasis,
we should mention that there's practically no emergencies in the prostate cancer world;
everything moves at a very slow pace, but one exception is that if the bone metastases
in the backbone start pushing on the spinal cord, the major nerve that runs down and controls
your legs, that can be an emergency because people can develop paralysis. So, people who
are aware that they have bone metastases should always be informed that if they develop any
sudden new back pain or any unexpected leg weakness, they need to go to the emergency
room right away. Don't even wait for the next morning because with timely radiation treatment
that metastatic site can be eradicated and the spinal cord activity can be preserved.
If it's allowed 24-48 hours to be non-functional, that is the metastasis push on the cord and
they choke off the blood supply to the cord, permanent paralysis is a possibility. It's
called spinal cord compression. It's pretty much the basic only emergency that we see
in the prostate cancer world.
So, when it comes ot the bones themselves, is there anything that patients, you know,
does the quality of the bone as far as it being weak or strong in any way affect how
they can handle treatment when they have metastasis?
Well, perhaps to a small degree, but more important is that aging men are already losing
calcium and developing osteoporosis with age, and then when you put them on testosterone
deprivation, that accelerates the process. The weakening of the bones from the cancer
directly is more common with other types of cancer. It can occur with prostate cancer,
but prostate cancer usually causes sclerotic metastasis, so in a sense, you could say it's
even strengthening the bone a little bit. So, pathologic fractures from cancer itself
are much less common with prostate cancer than other cancers, but they can occur.
So, I know one treatment in prostate cancer when it comes to metastases, we have Xofigo
and we have lutetium, so injectable forms of radiation. Can you speak to how those work
and have you seen that they've really eradicated bone metastases and people have gone into
remission?
Yeah, they are effective medicines. Usually, if there's only a limited number of metastatic
sites, we'll use beam radiation, but if there are more than half a dozen spots then there
are products like Xofigo which is FDA-approved. It's radium injected into the bloodstream
and it concentrates around the tumors and delivers a high dose of radiation to eradicate
bone pain and cancer cells because people have been shown to live longer with this treatment.
You mentioned lutetium, that's not yet FDA-approved. It is being actively researched and I believe
is FDA-approve in other countries like Australia and Germany, and we've had a few patients
that have gone overseas and have done well. They've responded nicely even in situations
where their other treatments had stopped working.
Thank you so much for watching! If you would like more information about bone mets or any
of the topics that we discussed today, you can go ahead and visit our website, PCRI.ORG.
Go ahead and visit our description to find more information and the timestamps of the
videos so you can see more about the questions that we asked. And please subscribe to our
YouTube channel. This helps us share prostate cancer videos with other patients all around
the world We hope you have a great week.