A Focus on Thyroid Cancer

Dr. Robert Udelsman, A Focus on Thyroid
Cancer
 May 17, 2009Welcome to Yale Cancer Center Answers with Dr. Ed Chu and
Francine Foss, I am Bruce Barber.  Dr. Chu is Deputy Director
and Chief of Medical Oncology at Yale Cancer Center and he is an
internationally recognized expert on colorectal cancer.  Dr.
Foss is a Professor of Medical Oncology and Dermatology and she is
an expert in the treatment of lymphomas.  If you would like to
join the discussion, you can contact the doctors directly at canceranswers@yale.edu and
the phone number is 1888-234-4YCC.  This evening Ed and
Francine welcome Dr. Robert Udelsman.  Dr.
Udelsmanis the Chairman of the Department of Surgery at
Yale School of Medicine and he is an expert on thyroid
cancer.Chu
Let's start off with a very basic question, what is thyroid
cancer?Udelsman
Thyroid cancer is a malignancy that originates in the thyroid gland
and there are several subtypes of thyroid cancer.Chu
Can you get into a little bit about the different subtypes of
thyroid cancer?Udelsman
There are four fundamental subtypes of thyroid cancer; papillary,
follicular, medullary and anaplastic. They are derived from cells
that originate in the thyroid gland.  I should also mention
that a primary thyroid lymphoma can also start in the thyroid
gland, and in fact, thyroid lymphoma is more common than the rarest
type of thyroid cancer, which is anaplastic thyroid cancer.Foss
 Tell us a little bit about how common thyroid cancer is.Udelsman
Thyroid cancer is actually fairly common, but we should step back
and think about the fact that thyroid nodules, where thyroid cancer
develops, are very common in the population in America. There are
about 35,000 new cases of thyroid cancer per year in the United
States.Foss
 Are there any specific risk factors for thyroid cancer?Udelsman
Yes, there sure are.  One risk factor is radiation exposure as
a child, particularly to the head and neck, although that process
is no longer done, for instance, for acne or for thalamic
enlargement.  However, we still have a new population of
patient's who have, for instance, mantle radiation therapy for
Hodgkin's disease and they are at risk for thyroid cancer
throughout their lives.  In addition, individuals, especially
children, who are exposed to radiation accidents, for instance, the
Chernobyl population, are all at risk for thyroid cancer for the
rest of their lives.2:12 into mp3 file 
http://www.yalecancercenter.org/podcast/Answers_May-17-09.mp3Chu
How about the radiation that kids and/or adults might be exposed to
with dental procedures?Udelsman
It is thought that the typical x-rays that individuals get for
dental procedures, or even spine surgery, is not a significant risk
factor for thyroid cancers. Those parents should not be overly
concerned about that population of patients.Foss
 Can we talk a little bit about thyroid nodules, which are very
common?  How often does a thyroid nodule lead to a thyroid
cancer?Udelsman
This is a very important and basic concept that a thyroid cancer in
almost all cases starts out as a small thyroid cancer that grows,
whereas if you have a thyroid nodule that is benign from the start,
it will probably remain benign for the entire lifespan of that
nodule.  That thyroid nodule can be seen in up to 15% of the
normal female population in the United States, but certainly 15% of
women in United States do not have thyroid cancers.Chu
Do thyroid nodules occur more frequently in women than men, because
your answer kind of suggested that?Udelsman
Yeah, you are absolutely right.  They sure do.  There is
about a 3:1 ratio of female to male predominance of thyroid nodules
in the female population.  It's a strange thing we see and
there are other endocrine tumors that also have a female
predominance.Chu
Do we know why, for thyroid nodules, it occurs more frequently in
females?Udelsman
You would think there would be a simple estrogen explanation or a
lack of testosterone or some other growth factor, but the truth is
we don't really have a clear explanation why they are more common
in women than men.Foss
 Do all women who have these nodules need to have them
biopsied?Udelsman
That's where we get into a little bit of complexity.  What do
you do if you have a thyroid nodule?  The answer sort of
depends on how it's found and the size.  Unfortunately, or
perhaps fortunately, because we do so much screening with
ultrasound examinations, we are finding more and more thyroid
nodules that are smaller and smaller and we have a real dilemma in
the field. What is the smallest size that indicates that you should
biopsy nodules as opposed to just watching it and monitoring
it?4:14 into mp3 file 
http://www.yalecancercenter.org/podcast/Answers_May-17-09.mp3Foss
 Are most of these nodules picked up by physical exam? How does one
know that one has a thyroid nodule?Udelsman
It's not uncommon for someone to say, "I was looking at myself in
the mirror and I saw a nodule," or "My doctor or my gynecologist
felt a nodule," and that's how a patient gets referred.  It
also happens that a patient goes for an incidental ultrasound for
carotid study to make sure they have adequate blood flow for their
carotid arteries, and they find an incidental thyroid nodule, we
also see that population of patients.  We see both types of
populations.Chu
Rob, do these nodules ever cause any alterations in the normal
function of the thyroid?Udelsman
As you know, thyroid hormone is critical for life, it gives you the
energy for living, and almost all thyroid cancers are
nonfunctional, they do not make thyroid hormone, but remember, a
thyroid nodule is just as thyroid nodule.  For instance, we
also see a wide variety of patients with thyroid hormone
abnormalities, patients with Graves' disease or hot toxic nodules,
these patients do have thyroid hormone abnormalities, but those are
not cancers.Foss
 Are there symptoms that a patient would experience if they had a
thyroid nodule?Udelsman
The first symptom would be a mass.  They would feel something
in their neck or they might experience a coughing sensation or
difficulty swallowing.  Pain is an advanced symptom, or loss
of function of a vocal cord such that they develop a hoarse voice,
those are advanced findings usually of advanced tumors.Chu
If any of these symptoms should be present in an individual, what
should they then do?Udelsman
As all things, if you have a hoarse voice for two days associated
with the cold and it goes away, it's probably not a big deal, but
if something persists or if there is a mass there, you should
consult with your primary care doctor.Chu
And that should be the general internist or primary care
physician?Udelsman
It feeds into many different ways in our society, it could be a
pediatrician, it could be an internist, and these days the
gynecologist is often the only primary doctor that many6:11 into mp3 file 
http://www.yalecancercenter.org/podcast/Answers_May-17-09.mp3women see.  It's an acceptable way to feed into it as well,
as well as an internist or family doctor.Foss
 Does it make any difference in women whether these nodules are
palpated at certain times of the month? Do they vary with the
menstrual cycle or with hormonal replacement therapy or any other
factors?Udelsman
I know of no data to answer that question specifically, although
you mention hormonal therapy, you are obviously thinking of
estrogen and progesterone, but if you do give thyroid hormone,
sometimes you can shrink these nodules.  But I know of no
clear relationship between estrogen and progesterone in shrinking
these nodules.Chu
If a nodule or mass is identified by the primary care physician,
what would be the next step?Udelsman
Often, but not always, these patients are then sent to an
endocrinologist.  An endocrinologist is an internal medicine
doctor with specialty training in endocrinology. At that point they
do some basic work, generally a history and physical examination
and measure some selective hormone levels, particularly a TSH, or
thyroid stimulating hormones, and that can suggest the function of
the thyroid gland.  But in most cases, most patients will
progress on to a biopsy and that's performed with a technique that
we refer to as FNA, which stands for fine needle aspiration.Foss
 Do patients need to have any form of x-ray before they go into the
biopsy?  You mentioned that they have an ultrasound for the
diagnosis, but do they need to have other x-rays like CAT
scans?Udelsman
There has actually been a dramatic shift in how we manage
these.  Back, I would say 15 years ago, most patients would go
into a nuclear medicine study, an I-131 study.  We almost
never do that in the primary management.  As far as CT scans,
PET, or MRI scans, those are expensive studies that are
unnecessary, they lack the sensitivity that we need and we find a
simple ultrasound to be the ideal study in the initial work-up of a
thyroid nodule.Chu
Once a biopsy is done, then obviously the pathologist is going to
play a critical role in terms of evaluating that tumor tissue or
that tissue.Udelsman
I am so glad that you asked me to be on the this show, because it
gives me a chance to talk about the pathology inside of pathology,
and the art form that it is.  Reading the slides from a
thyroid biopsy is an art form and there are a few people who really
have exquisite skills8:22 into mp3 file 
http://www.yalecancercenter.org/podcast/Answers_May-17-09.mp3
 in doing that, and the subtle abnormalities that they can see
under the microscope, not all people who read slides have those
well-developed skills. The quality of the person who biopsies a
nodule, and the person who reads it, are critical to making good
decisions for a patient.Foss
 One thing that's really different about thyroid cancer compared to
some of the other tumors that we treat is that we require a piece
of tissue.  We are not satisfied with the fine needle
aspirate, and you have touched on this a little bit about the
critical nature of the cytopathology.  Do you often have to go
on to get a bigger piece of tissue?Udelsman
The answer is yes.  But when have to go on, it usually
involves more than just a piece of tissue, it usually involves an
operation.  The fine needle aspirate cytology, when we get a
good quality specimen, can be diagnostic of cancer, and if it
unequivocally shows a cancer, we go straight to definitive surgery;
we do not do any in between steps because we have essentially 99.9%
confidence in that.  However, about 20% of the aspirates have
what we call indeterminate cytology and getting more tissue or a
bigger core piece of tissue would not help us.  We are
actually forced to remove the lobe containing the thyroid gland to
actually remove a piece of the organ to answer the question whether
it's malignant or benign.Chu
Are there any specific types of thyroid cancers that might have an
increased risk for spreading beyond the local confines of the
thyroid?Udelsman
By definition any thyroid cancer could spread to many areas of the
body, but different subtypes that I mentioned earlier have
different rates of spread to different systems.  For instance,
papillary carcinoma of thyroid spreads to lymph nodes very early in
its course, whereas, others such as follicular, has more of a blood
stream spread to other areas such as the lungs, or perhaps the
bones.  Medullary cancer of the thyroid tends to stay
localized to the local area and the lymph nodes, and anaplastic can
basically go anywhere and is very aggressive locally.  Each
has their own flavor to them.Foss
 A lot of times in advanced cancer we see patients who develop what
we call an unknown primary; they present with a cancer of
indeterminate origin and in some cases that turns out to be a
thyroid cancer.  How often do you see thyroid cancer
presenting as an unknown primary?Udelsman
That's a wonderful question.  Occasionally, we will see a
patient who presents with a lesion somewhere else in the body,
maybe their leg or bone somewhere, and finally we get enough tissue
and it is the pathologist or the cytopathologist that says, "You
know, this10:51 into mp3 file 
http://www.yalecancercenter.org/podcast/Answers_May-17-09.mp3
 looks like a thyroid primary."  There are special tests they
can do by measuring certain markers like thyroglobulin that can
answer that question.  If in fact they have wide spread
metastatic disease outside the thyroid gland, believe it or not in
that situation we are actually relieved to some extent, because
that is a treatable cancer.  Perhaps not curable, but
treatable, and we can then go and remove the thyroid gland and
treat those patients with radioactive iodine. The radioactive
iodine can have great efficiency in treating tumors even outside
the neck and even in areas of bone.  In some ways it's a
convoluted way to get there, but sometimes it works.  In
addition, every once in a while we see a patient with a thyroid
nodule who actually has metastatic disease from something else,
particularly something like renal cell carcinoma that goes to the
thyroid gland, and occasionally that can cause a real diagnostic
dilemma for us figuring out what's going on.Chu
I guess that's why the I-131 scans were so in vogue, because people
used it as a way to see if the thyroid tumor had spread outside the
thyroid.Udelsman
They do, but of course, we use a lot of I-131 probes and scans once
we have removed the thyroid gland.  Can I digress to I-131 for
just a moment?Chu
Sure.Foss
 Sure.Udelsman
In the treatment of thyroid cancer there are really three
functional treatments.  The first is surgery, we remove the
tumor.  The second is we use I-131, which I will discuss it in
a little bit more detail, and the third is we administer thyroid
hormone long term to suppress the pituitary secretion of TSH. But
what's so exciting about I-131, Ed, is that it's a magic bullet.
 Because of the way thyroid hormone is made, it's made from
three molecules of iodine or four molecules of iodine resulting in
T3 and T4, it's so concentrated in thyroid producing cells we can
then administer radioactive iodine like a magic bullet and have
tumor kill ratios that are so advantageous with little toxicity to
normal tissues.  It's a wonderful thing that we have for the
thyroid gland and part of the reason our patients do so well. 
If only we had such a thing for other tumors that was so specific
for the cancer that we treat.Foss
 Is the I-131 therapy equally effective for all the different types
of thyroid cancer?Udelsman
No it's not, and as you might predict, the more its like normal,
the more likely I-131 is to work, and it's exactly as such. 
So, papillary cancers are very effectively treated. 
Follicular13:15 into mp3 file 
http://www.yalecancercenter.org/podcast/Answers_May-17-09.mp3
 is fairly well, but a little less.  Hurdle cells a little
bit, but much less likely, and finally anaplastic is probably a
waste of time; it doesn't work in almost any of those patients.Chu
I know we already began to talk about the different treatment
strategies, but one thing that might be good to refresh our memory
on is, is there any kind of genetic component to the development of
thyroid cancer?Udelsman
There sure is. Most thyroid cancers are sporadic and there is no
clear genetic component, there is a risk factor for radiation
therapy, but there are clear families that have thyroid cancer. For
instance, medullary thyroid cancer, the third type that I mentioned
earlier, occurs in three settings in the familial setting.  It
occurs in isolated familial medullary thyroid cancer, and it occurs
in a syndrome that we refer as MEN2A and MEN2B.  MEN means
multiple endocrine neoplasia. All three of those are autosomal
dominant patterns, which means that half the children, boys or
girls, will be effected by the disease by a random event during
conception.  50% of the children will inherit this gene and
once they inherit the gene the likelihood of developing thyroid
cancer in their lifetime approaches 100%, and we have a genetic
screening test for these children.  Now when we have a family,
and we usually know who these families are shortly after birth, we
can screen the child's blood and tell the parents with virtually
100% confidence that yes, your child will develop thyroid cancer in
their lifetime.Foss
 Thank you for that information. I would like to talk in detail
about that as well as other therapies for thyroid cancer when we
return from the break.  You are listening to Yale Cancer
Center Answers, and I am here discussing thyroid cancer with Dr.
Robert Udelsman.Foss
 Welcome back to Yale Cancer Center Answers.  This is Dr.
Francine Foss and I am joined15:53 into mp3 file 
http://www.yalecancercenter.org/podcast/Answers_May-17-09.mp3
 by my co-host Dr. Ed Chu and Dr. Robert Udelsman, Chairman in the
Department of Surgery at Yale School of Medicine, and we are here
today talking about thyroid cancer.  We talked a little bit
about familial thyroid cancer and detecting it using a genetic
test, detecting people in the family that are prone to develop
this.  Can you spend a minute telling us what kind of
screening tests should be done on those family members?Udelsman
It's really fortunate for us that we now we have a sensitive blood
test.  So for a child, or anybody in the family, potentially a
parent of someone with this, we simply draw peripheral blood, and
that blood is sent to a special laboratory to be screened and the
genetic test, which in this case is called the RET proto-oncogene,
has a very high sensitivity, but not 100%.Foss
 Do those children then go on to get frequent ultrasounds of their
thyroid?Udelsman
They could, but we also have other tumor markers in this
case.  In this case, medullary thyroid cancer makes a very
specific marker called calcitonin.  It also makes another
marker, which is less sensitive and specific, called CEA, but if
the calcitonin level is elevated, we know these children already
have minimum C cell hyperplasia, and more likely disease in the
from of cancer, but it doesn't really matter, because once they
have the genetic abnormality, we recommend prophylactic surgery at
certain ages once we know they have a genetic abnormality. This is
an example of where, because of a genetic screening test, we can
now do prophylactic or preemptive surgery and prevent cancers from
developing in the first place.Chu
That's pretty impressive.  Let's go backwards to the
therapeutic options.  Again, the most common type of thyroid
cancer is papillary thyroid cancer.Udelsman
Yes.Chu
And the typical approach in that setting would be?Udelsman
The patient presents with the nodule and usually that patient will
then go on to a fine needle aspiration biopsy. In papillary cancer,
the fine needle aspiration techniques are very sensitive, so
usually if we get a diagnosis and its positive, the next question
is, what's the next step?  Well in our hands, we recommend at
minimum for all patients with biopsy proven papillary thyroid
cancer, a total thyroidectomy, removing the entire thyroid
gland.  But there is a big debate in the world right now about
whether or not we should also be doing routine lymph node
dissections in what we called the central neck, and just to mention
for the second, we are in the process of designing a randomized
prospective18:25 into mp3 file 
http://www.yalecancercenter.org/podcast/Answers_May-17-09.mp3
 trial to address this very question, because experts in the field
in their heart of hearts don't know whether it's the best thing in
individuals who have no evidence of lymph node disease. Because, as
you might imagine, nothing comes for free, and if you routinely
remove lymph nodes, you are more likely to also cause injury to the
parathyroid glands, the nerves, or to the vocal cords.  To do
the proper study, you have to randomize patients to yes and no
treatments.Foss
 I was actually going to ask you that question.  Could you
talk a little bit about the complications from a total
thyroidectomy?Udelsman
First, I would like to mention to you that there is clear
relationship between the experience of the surgeon and the
frequency of complications; it's so fundamental to everything that
we do.  But the most common significant complications after
thyroid surgery or injury to the nerve to the vocal cords would
result in a hoarse voice. Whereas, the other complication is injury
to the parathyroid glands and the parathyroid glands are glands
that sit next to the thyroid gland and control calcium
metabolism.  Now we can replace those with vitamin D and
calcium, but if you do that to a 5-year-old child and they don't
have normal calcium metabolism, that child will never grow
normally.  The risk in children is actually greater than in
the adults.Chu
And in the old days, a lot of times along with the thyroid, the
parathyroid would also be taken out, but now you really try to
preserve the parathyroid.Udelsman
We go to great trouble to preserve the parathyroid, and in fact,
the best thyroid surgeons are also very good parathyroid
surgeons.  They live in the same neighborhood and have very
different functions, but are intimately associated with each other
because of their blood supplies.Foss
 If a patient doesn't respond, say to the radioactive iodine, and
they have persistent or metastatic thyroid disease, a thyroid
cancer, what do you do at that point?Udelsman
That starts a staging work-up.  Firstly, we can also measure
something else called thyroglobulin to measure the amount of
disease that they have.  For instance, if we have lymph nodes
in the neck and we know they have disease, we might consider going
back and doing surgery because in two or three hours in the
operating room we could remove more tumor than you can kill with
I-131.  I-131 is very good for microscopic or small disease,
but for gross, or what we called macroscopic disease, surgery is
better.  In other areas such as a weight bearing extremity
surgery in combination with radiotherapy, other treatments would be
considered.  The goal of course is to remove all the disease,
but there20:56 into mp3 file 
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 are critical areas that we can't because it would cause so much
destruction to normal tissues.Chu
Rob, is there ever any role for external beam radiation therapy to
the neck?Udelsman
There is.  External radiotherapy will kill any rapidly
dividing cells including thyroid tissues, but of course external
beam isn't intelligent like I-131. Not to demean it, but what it
will do is also destroy other tissues like the tissues in the
esophagus.  The complication rate associated with it is higher
than with I-131.  In addition, the patient gets what we call a
woody indurated neck, its very firm and fixed and makes subsequent
surgery difficult, and at times impossible.Foss
 When we think about chemotherapy approaches for thyroid cancer,
traditionally we thought that chemotherapy doesn't work very well.
Are there any novel approaches that are being developed?Udelsman
For the most part, as you stated, chemotherapy is not the main
stream treatment, and that's why endocrinologists tend to manage
these patients the most, but we have two great interests in
clinical trials right now at Yale Cancer Center.  One is in
the treatment of advance medullary thyroid cancer, and the other
one is that very rare form of anaplastic thyroid cancer. 
There are two open protocols right now.  The medullary thyroid
cancer involves a new type of a drug and early results look very
promising in this trial.  These are for patients who don't
have a good surgical option.Foss
 Are these new drugs small molecules like we have talked a lot
about angiogenesis molecules and signal transduction inhibitors?
Are those types of therapies pertinent in thyroid cancer?Udelsman
They sure are, and in fact, in the medullary cancer trial it's a
tyrosine kinase receptor type molecule to block these receptors.
The beauty of this particular trial is the toxicity profile is very
low compared to more traditional forms of chemotherapy.  So,
the preliminary results are pretty exciting.Chu
What's really fascinating about the small molecule is that it's
targeted specifically at the pathway that's responsible for the
development of medullary, the carcinoma of the thyroid.Udelsman
Absolutely, and I would also like to say this is a good example
where one of our surgeons, Julie Ann Sosa, worked with one of our
oncologists, Hari Deshpande, as well as with 23:09 into mp3 file 
http://www.yalecancercenter.org/podcast/Answers_May-17-09.mp3
 other colleagues and it's a true multidisciplinary approach to the
treatment of thyroid cancer, and I think that's exactly what Yale
Cancer Center does so well, bringing different groups of people in
with various expertise to treat these tumors, because from the
patients perspective, they just want to know they are getting the
best care in the world.Foss
 Can you talk about quality of life issues for patients who have
thyroid cancer as they move through this process with surgery and
radioactive iodine? What are some of the issues that patients
face?Udelsman
There are a lot of issues they face.  Of course, surgery is a
relative negative, but it's a short duration event.  You come
in, you get an operation, and you go home, and most patients are
very happy with that.  Sometimes we do things like thyroid
hormone withdrawal, where we take away their thyroid hormone, we
make them hypothyroid before we give the radioactive iodine, and
some patients don't like that and there is a new technique where we
actually stimulate them with synthetic TSH and then give them the
radioactive iodine treatment, and I believe that will become more
and more common in the future.  The radioactive iodine is not
a difficult thing to do and it's almost always done now as an
outpatient.  The only issue there is protecting, for instance,
children in the house, to make sure we don't expose them to the
radioactivity.  The other forms of treatment, for instance,
chemotherapy, do have some consequences to it, but for the most
part the great majority of patients with thyroid cancers will be
cured of the disease, or if not cured, they will live with a low
grade indolent disease and most of them will actually have a normal
lifespan.Chu
Are there any potential concerns with the use of radioactive
iodine? You know, long term consequences pertaining to the
development of secondary cancers?Udelsman
Ed, as usual, you are right on the money. The more radioactive
iodine you get, the more complexity and the more complications you
will have.  So, yes, as you approach higher and higher doses,
and ballpark that's about 1000 mc, you will see other cancers
develop, particularly leukemia's, and you won't be surprised by
that because the radioactive iodine can go to the blood
stream.  So, as we start upping our dose we start to get more
and more concerned and start thinking about alternative
therapies.Foss
 If the patient has radioactive iodine and their disease goes into
remission and then say a couple of years later it comes back again,
can they get radioactive iodine a second time?Udelsman
A second, a third, and even a fourth time, and there are different
ways of regulating how much to give, but yes, it can be repeated
multiple times.25:25 into mp3 file 
http://www.yalecancercenter.org/podcast/Answers_May-17-09.mp3Chu
Do the thyroid tumor cells ever become resistant to radioactive
iodine?Udelsman
Yeah they do, and that's a problem for us. As a ballpark figure, we
talk about well differentiated thyroid cancer, which basically
means papillary, follicular, and sometimes medullary, but roughly
85% of those take up the radioactive iodine, of course, that means
that 15% don't, and as you go farther and farther into the
treatment it's as if the radioactive iodine kills out the sensitive
cells, and the resistant cells remains, and then they become the
predominant cells.  So, yes tumors will lose their ability to
take up radioactive iodine and that does cause great problems for
us.Foss
 Can I go back and just ask another question about
prevention?  We talked a lot about the potential role of
radiation in patients with let's say with Hodgkin's disease, what
about therapeutic tests such as CAT scans? Some of our patients get
CAT scans every three months and traditionally we do not shield the
thyroid, is that something the patienst should be worried
about?Udelsman
I think the short answer is yes.  CAT scans actually have a
fairly high dose of radiation compared to a common chest x-ray, for
instance, and in fact, James Brink, the Chief of Radiology at
Yale-New Haven Hospital, and the director of the department, has a
particular interest in this area.  When I last discussed this
with him, he actually thinks we ought to be a little bit more
conservative about it.  The danger is patients go to one
hospital to get the CAT scan, and then get recurrent kidney stones
perhaps, and some patients are getting four or five CAT scans a
year and so, yes, overtime I do believe that radioactive exposure
can accumulate in some of those patients.Chu
Obviously you know thyroid is removed with surgery, what's the need
for thyroid hormone replacement overtime?Udelsman
Thyroid hormone is a requirement for life.  If you don't have
a thyroid hormone you will eventually not survive, although you can
go a very long time becoming hypothyroid.  The answer is, we
replace all of our patients with thyroid hormones who have surgical
removal of the thyroid gland, it's relatively easy to do, we give
them a synthetic form of thyroid hormone because we can accurately
calculate the dose and we can easily monitor TSH levels to prove
that they are in perfect homeostasis or in perfect balance.Foss
 Let's just go back to that issue of the testing that could be done
for the patients who may have inherited thyroid cancer. Are those
blood tests pertinent also in terms of screening other populations
of patients for thyroid cancer?27:49 into mp3 file 
http://www.yalecancercenter.org/podcast/Answers_May-17-09.mp3Udelsman 
       
 Generally speaking, in the United States, we do not do wide
screens of patients for these genetic screens.  Although in
Europe, what they do for patients with the dominant nodule, is they
measure a serum calcitonin level, which is the screen for
medullary.  The reason its relevant is the operation that we
do for medullary is somewhat more aggressive than for papillary,
and the best time to do the best operation is the first operation,
that is 20% of my practice is remedial surgery.  I wish that
0% was for medial surgery, because the second operation, and third,
or fourth operations, are much more difficult than the initial
exposure, so there is some logic to doing it, but it's probably not
cost effective in doing calcitonin screening because it's
relatively expensive and it's a relatively rare disease.Chu
Rob, it's amazing how quickly the time has gone and we would like
to thank you for joining us this evening. We look forward to having
you come back to hear more about the latest advances in your
thyroid cancer program.Udelsman
Thank you Ed and Francine.Chu
You have been listening to Yale Cancer Center Answers. I would like
to thank our guest expert Dr. Robert Udelsman for joining us. 
Until next time, I am Ed Chu from the Yale Cancer Center wishing
you a safe and healthy week.If you have questions or would like to share your comments,
go to yalecancercenter.org where you can also subscribe to our
podcast and find written transcripts of past programs.  I am
Bruce Barber and you are listening to the WNPR Health Forum from
Connecticut Public Radio.