Frequently Asked Questions
- 1 What is Medullary Thyroid Cancer?
- 2 My Dr. does not seem to know much about MTC, what should I do?
- 3 What is an MTC Center of Excellence?
- 4 What kind of Dr. should I see for MTC?
- 5 Is MTC serious?
- 6 Will my children develop MTC?
- 7 What parts of the body can MTC affect?
- 8 How do I know the "Stage" of my MTC?
- 9 How does MTC treatment differ by stage?
- 10 How do I know my doctor is following the right treatment plan for my MTC?
- 11 What is calcitonin and what role does it play in MTC?
- 12 Can MTC be prevented?
- 13 How come MTC was never found in my body until now?
- 14 What is CEA, and what does it mean for an MTC patient?
- 15 Why are Calcitonin levels important?
- 16 What is CDT (Calcitonin Doubling Time), what does it mean for an MTC patient, and how is it calculated?
- 17 How do medications treat MTC?
- 18 How often will I need blood work and scans done?
- 19 How am I going to pay for all the things associated with MTC?
- 20 Will I be able to work full time with MTC?
- 21 What is my life expectancy with MTC?
- 22 Where can I find more information that has the facts about MTC? What are more sources of information about MTC that I can access online?
- 23 Why do I need Genetic testing/counseling?
- 24 What is my chance of a full recovery?
What is Medullary Thyroid Cancer?
MTC is a carcinoma of the connective tissue (the "C" cells) within the thyroid. A good definition exists in Wikipedia: http://en.wikipedia.org/wiki/Medullary_thyroid_cancer
Medullary thyroid cancer is completely different than the more common papillary and follicular types. Medullary thyroid cancer is usually not classified in terms of differentiation because it does not arise from the thyroid cells themselves, but rather from the specialized "C-cells" that are in between the thyroid cells. These C-cells are also sometimes referred to as parafollicular cells. They are found mostly in the upper and middle parts of the thyroid and they produce a substance called calcitonin which can serve as a marker for Medullary Thyroid Cancer. Although we know that calcitonin is somehow involved in the body's regulation of calcium, we do not know its exact function. We do know that people who have had their thyroids removed surgically, do not require replacement of calcitonin for normal function and a healthy life.
My Dr. does not seem to know much about MTC, what should I do?
Medullary Thyroid Cancer (MTC) is a fairly rare form of thyroid cancer, and because of that, many doctors (including many oncologists and endocrinologists) have little to no experience with the disease. One of the most important decisions you can make in your cancer care is to choose a doctor who has a deep understanding of this particular disease. Therefore, it is a best practice in MTC care to seek initial treatment at an MTC Center of Excellence.
What is an MTC Center of Excellence?
An MTC Center of Excellence is a medical facility that has a focused practice in researching, diagnosing, and treating Medullary Thyroid Cancer. Doctors at these centers routinely see dozens of MTC cases and are typically involved in the latest research, conducting and monitoring clinical trials, and formulating treatment protocols.
If you look at the ThyCa Medical Advisory Council, (those facilities are a good place to start), at the International Thyroid Oncology Group (ITOG) site, or on the Center of Excellence page on this wiki.
A partial list, in random order:
- The University of Michigan’s Multidisciplinary Thyroid Cancer Clinic, Anne Arbor, MI
- MD Anderson Cancer Center, Houston, TX
- NY Thyroid Center at Columbia University, NYC, NY
- Memorial Sloan-Kettering Hospital, NYC, NY
- Mayo Clinic, Rochester MN
- Massachusetts General, Boston, MA
- Johns Hopkins, Baltimore, MD
- Cleveland Clinic, Cleveland, OH
- Siteman Cancer Center, Univ. of Washington, St. Louis, MO
- Yale School of Medicine, New Haven, CT
What kind of Dr. should I see for MTC?
Care for Medullary Thyroid Cancer is typically managed by a multi-disciplinary medical team. In many cases, an Endocrinologist coordinates care with the necessary surgeons, radiologists, and oncologists to see that you are getting the best care.
Is MTC serious?
Yes, MTC is a serious disease. Left untreated, it can be a fatal disease. Surgery is the only way to cure MTC, provided it is treated before it escapes the thyroid. There is not currently a method to "cure" metastatic MTC, although with proper treatment and management, a patient can lead a long and healthy life. There is significant progress being made on pharmaceuticals to control the growth and spread of MTC. See the Trial_drugs page and watch the MTC News page for updates.
Will my children develop MTC?
Medullary Thyroid Cancer can be hereditary, or it can be sporadic. With the sporadic form, your children are not at any greater risk than anyone else of developing MTC. However, with the hereditary forms of MTC (known as MEN2A, MEN2B, and Familial MTC (FMTC)), blood relatives of the patient (children, grandchildren, siblings, and parents) should be examined for the MTC gene. Therefore, it is very important that MTC patients undergo genetic testing to determine the root cause of their disease, and locate any family members that my carry the gene and not be aware.
What parts of the body can MTC affect?
If MTC is diagnosed and treated while still contained within the thyroid, typically only the thyroid and perhaps the parathyroids are affected. However, in many cases, MTC is not diagnosed until it has grown outside of the thyroid and into the lymph system. MTC is typically a very slow growing cancer, but it tends to spread to distant locations fairly efficiently. While the different forms of MTC act slightly differently in where and how quickly they spread, it is not unusual to see MTC metastasize (spread) to the head, neck, and chest lymph nodes, bones in the rib cage, spine and pelvis, as well as in liver and lung tissue. These metastatic sites might be minuscule (even too small to "see" on an image or scan) but they contribute to the overall tumor load a patient must bear.
These microscopic metastatic sites are often managed through observation and are acted upon only when they become large enough to be intrusive.
How do I know the "Stage" of my MTC?
A complete description of staging and nodal involvement is available here: http://www.springer.com/cda/content/document/cda_downloaddocument/0-387-29014-1_thyroid.pdf?SGWID=0-0-45-314789-0
- Age is not a factor in staging patients diagnosed with medullary thyroid carcinoma (MTC). MTC staging is determined by the size and distribution of MTC tumor cells:
- Stage I Thyroid Cancer - The diameter of the tumor is no more than two cm (less than an inch wide). No cancer was found in regional lymph nodes or distant sites in the body.
- Stage II Thyroid Cancer - The spread and the growth of the cancer may be qualified in two ways:
- The diameter of the primary tumor has grown and ranges from two to four cm. No cancer was found in regional lymph nodes or distant sites in the body.
- The primary tumor is larger than four cm in diameter has started to grown outside of the thyroid. No cancer was found in the lymph nodes or other parts of the body.
- Stage III Thyroid Cancer - The spread and the growth of the cancer may be qualified in two ways:
- The tumor can be any size and may have grown slightly outside the thyroid.
- The tumor has spread to lymph nodes around the thyroid in the neck but not to distant sites.
- Stage IV Thyroid Cancer - The most advanced stage of thyroid cancer is differentiated in to Stage IVA, Stage IVB or Stage IVC depending on where the cancer has spread to:
- Stage IVA - Cancers in this stage have grown beyond the thyroid gland and have spread into nearby tissue. Cancers in this stage may have also spread to lymph nodes in the neck and upper chest, but not to distant sites.
- Stage IVB - The primary tumor has grown into the spine or into nearby large blood vessels. The cancer may or may not have spread to lymph nodes, but has not reached distant sites.
- Stage IVC - The thyroid cancer has spread to distant sites, but may or may not have grown outside of the thyroid or into the lymph nodes.
How does MTC treatment differ by stage?
The type of treatment your doctor will recommend depends on the type and stage of the cancer and on your overall health. Listed below are "typical treatment plans". however, your doctor may have reasons for recommending other treatments. Don't hesitate to ask him or her questions about your treatment options.
Most doctors advise that patients diagnosed with medullary thyroid carcinoma (MTC) be tested for other tumors that are typically seen in patients with the MEN 2 syndromes, such as pheochromocytoma and parathyroid tumors. Screening for pheochromocytoma is particularly important, since the unknown presence of this tumor can make anesthesia and surgery extremely dangerous. If they are forewarned, surgeons and anesthesiologists can medically pre-treat the patient to make surgery safe.
- Stages I and II: Total thyroidectomy is the main treatment for MTC and often cures patients with stage I or stage II MTC. Nearby lymph nodes are usually removed as well (central compartment or modified radical neck dissection). Because the thyroid gland is removed, thyroid hormone therapy is needed after surgery. For MTC, thyroid hormone therapy is meant to provide enough hormone to keep the patient healthy, but it does not reduce the risk that the cancer will come back.
Because MTC cells do not take up radioactive iodine, there is no role for radioactive iodine therapy in treating MTC. Still, some doctors advise giving a dose of radioactive iodine to destroy any remaining normal thyroid tissue. If MTC cells are in or near the thyroid, this may affect them as well.
- Stages III and IV: Surgery is the same as for stages I and II (usually after screening for MEN 2 syndrome and pheochromocytoma). Thyroid hormone therapy is given afterward. When the tumor is extensive and invades many nearby tissues or cannot be completely removed, external beam radiation therapy may be given to try to reduce the chance of recurrence in the neck.
For cancers that have spread to distant parts of the body, surgery, radiation therapy, or similar treatments may be used if possible. If these treatments can't be used, Vandetanib or other targeted drugs may be tried. Chemotherapy may be another option. Because these cancers can be hard to treat, another option is taking part in a clinical trial of newer treatments.
- Recurrent cancer: If the cancer recurs in the neck or elsewhere, surgery, external radiation therapy, targeted therapy (such as vandetanib), or chemotherapy may be needed. Clinical trials of new treatments may be another option if standard treatments aren't effective.
- Genetic testing in Medullary Thyroid Cancer: If you are told that you have MTC, even if you are the first one in the family to be diagnosed with this disease, ask your doctor about genetic counseling and testing. Genetic testing can find mutations in the RET gene, which is seen in cases of familial MTC and the MEN 2 syndromes.
If you have one of these mutations, it's important that close family members (children, brothers, and sisters) be tested as well. Because almost all children and adults with mutations in this gene will develop MTC at some time, most doctors agree anyone who has a RET gene mutation should have their thyroid removed to prevent MTC soon after getting the test results. This includes children, since some hereditary forms of MTC affect children and pre-teens. Total thyroidectomy can prevent this cancer in people with RET mutations who have not yet developed it. Of course, this means that lifelong thyroid hormone replacement will be needed.
If your genetic testing shows that your case is sporadic (no gene mutation caused the cancer), ask your doctor to test the tumor tissue itself for mutation. In rare instances, even though the cancer occurred sporadically, the tumor cells mutate and begin behaving like MEN2A tumors. This is rare, but important to know as the treatment plan will be different these cases.
How do I know my doctor is following the right treatment plan for my MTC?
The American Thyroid Association has published guidelines for the treatment of Medullary Thyroid Cancer. It is available for download here http://www.thyroid.org/professionals/publications/documents/MTC_Guidelines.pdf
What is calcitonin and what role does it play in MTC?
The parafollicular cells (the "C" cells in your thyroid that MTC affects) produce a substance called calcitonin which can serve as a marker for Medullary Thyroid Cancer. Post-surgery, any remaining cancerous cells will usually continue to produce calcitonin, and that become an indicator of the speed at which remaining cancer cells are multiplying. Doctors follow calcitonin levels to calculate the calcitonin doubling time (CDT). This is used as an indicator, along with another test for CEA, of the volume of remaining MTC cells and how quickly those cells are multiplying. Although we know that calcitonin is somehow involved in the body's regulation of calcium, we do not know its exact function. We do know that people who have had their thyroids removed surgically and who have no remaining parafollicular cells, do not require replacement of calcitonin for normal function and a healthy life.
Can MTC be prevented?
There is no known cause for sporadic MTC,and therefore it is impossible to prevent. However, the spread of familial MTC can be controlled by performing prophylactic thyroidectomies on the siblings and offspring of known MTC patients, thus preventing those relatives from developing familial MTC in the future.
How come MTC was never found in my body until now?
MTC often lies undetected. In sporadic MTC, unless an unusual lump or pain is felt in the neck area, MTC is often not diagnosed until the patient presents with a lack of energy, or digestive issues that are caused by the increased level of calcitonin in their bloodstream. Sometimes a routine blood test will show increased CEA, and that will lead a physician to the MTC.
Familial MTC is often detected by testing as a result of a relative discovering they have MTC. When genetic testing shows that a person's MTC was caused by a genetic issue, the geneticist will inform all the family members that might be affected and instruct them on how to proceed. This often results in the discovery of pre-cancerous conditions or undetected, operable MTC that has not, up to that point, been an issue. Families receiving these instructions should follow them carefully in order to prevent future issues with this disease.
What is CEA, and what does it mean for an MTC patient?
CEA, or Carcinoembryonic Antigen, is a substance that may be made by advanced MTC that should be tested for in the blood along with calcitonin. CEA can also be used as a marker for possible later recurrence of disease. More aggressive MTC often make more CEA.
Why are Calcitonin levels important?
A blood test to check the level of calcitonin in the blood should be done in patients with an established or suspected diagnosis of MTC. It can also be used as a screening test for patients with a family history of MTC, who are at risk of developing the disease. Calcitonin levels can be used to estimate how much cancer is in a person's body, as well as monitor for persistent or recurrent disease after surgery (as a tumor marker). Depending on the initial calcitonin level, additional radiographic studies such as a CT scan of the chest, neck, and/or liver may be ordered. Calcitonin is NOT produced at a standard rate by different patients with the same disease. In some patients, their MTC emits very little or no detectable calcitonin while in others, a great deal of calcitonin is produced by the MTC. More important than the volume of Calcitonin present at any given moment is the rate at which that volume increases over time. This is calculated at the Calcitonin Doubling Time (CDT).
This article helps describe Calcitonin's relationship to Calcium in the body.
What is CDT (Calcitonin Doubling Time), what does it mean for an MTC patient, and how is it calculated?
The monitoring of calcitonin levels play an important role in the follow-up and management of patients with medullary thyroid cancer. Calcitonin Doubling Time is the measurement of the increase of an individual's calcitonin level over a long period of time, typically a rolling two year period starting at the lowest measurement post-surgery. Calcitonin doubling times of > 2 years seem to be associated with a better long term prognosis then those < 6 months. A CDT Calculator is available here: http://www.thyroid.org/professionals/calculators/CDTC.php
How do medications treat MTC?
Unlike the “differentiated” thyroid cancers (Papillary and Follicular Thyroid Cancers) that are cancers of the iodine-seeking thyroid cells, MTC is a cancer of the “C” cell, a connective tissue that does not attract iodine. Therefore, radioactive iodine (RAI), the prevalent treatment for papillary and follicular thyroid cancer post surgery is ineffective for MTC.
MTC is treated medically, surgically, and radiologically. In terms of medicinal treatments, there are primarily two forms of medicine – traditional “chemo” treatments, and “targeted pharmaceuticals”. There are also a number of medicinal apporaches to treating symptoms and side effects encountered by the MTC patient, but those are varied and are standard approaches that won’t be covered in this answer.
- “Chemo” treatments - There has been limited success in the use of systemic chemotherapy to treat patients with metastatic MTC. The most prevalent traditional chemo tried for MTC is doxorubicin, and has shown very limited response. Some work has been done to position the doxorubicin within the MTC cell using magnetic microparticles, again with limited success.
- Targeted pharmaceuticals – The most current research is focused on targeted pharmaceuticals that address MTC through a function known as “growth blocking.” The most advanced research is investigating the mechanism by which cells “communicate’ that they are to divide and multiply. This research focuses on the VEGF receptor and with Receptor Tyrosine Kinases. The idea is to interrupt the communication pathway so that the MTC cell does not divide and multiply. Progress has been made on this mechanism over the last two decades and in 2011, the first drug using this mechanism was approved for MTC treatment. That drug, generically known as Vandetanib, and marketed by Astra-Zeneca branded as Calpresa, has shown promising results in clinical studies and is now available to the general market via prescription. Calpresa is not a “cancer cure,” it is a cancer growth blocker, interrupting the growth factors that trigger the cancer cells to divide and grow. In 2013, Cabozantinib with the brand name Cometriq was approved. In Trials are RET inhibitors selective just for RET with less side effect profiles, LOXO and BLU. There is also a RET and BRAF inhibitor RXDX105 in trials. LOXO is anticipated for fast track approval by 2020.
Other inhibitors currently in Trials are Reprotrectinib and in 2020 this inhibitor will be tried.
NET tumor agents like Sandostatin, Lutetium 177, Lutathera, and several others, have been used since Medullary is a NET Cancer and a Carcinoid. These agents slow down the tumor growth and can reduce tumors. But neither the TKI or NET cancer drugs or Immune Therapies have shown to cure. They slow down the growth or reduce some tumors only.
Another Agent ONC201 is currently in Trials for NET Tumors and this works with a protein ATF4 that promotes natural Tumor Suppressors. You do not need a RET mutation to use NET cancer agents.
Immune therapy Trials for Keytruda and a vaccine against CEA have been tried at the NIH with limited results.
Scientists are also investigating other ways of doing this such as:
- Lowering levels of the growth factor in the body
- Blocking the signals inside the cell that start up when the growth factor receptor is triggered
- Blocking the growth factor receptor on the cancer cell
Most of the treatments developed so far work by blocking the signalling process. Cancer cells are often very sensitive to growth factors. So if we can block them, we may be able to stop cancers from growing and dividing. Growth factor blockers (inhibitors) are an exciting new way of treating cancer. Scientists are working on developing new inhibitors for different types of growth factors.
How often will I need blood work and scans done?
The frequency of blood work and scans depends on your doctors assessment of need. Usually, after surgery or radiation treatments, doctors like to see patients, perform blood tests and order scans more frequently. Sometimes these are done monthly (particularly blood tests and doctors appointments) until the doctor is assured that the disease is stable; then the tests can be scheduled every 3 or six months. Scans are usually done every 3, 6, or 12 months, depending on the doctor's assessment of your particular case.
How am I going to pay for all the things associated with MTC?
In many parts of the world, health care is supplied through a centrally funded government program and at little to no direct cost to the patient. In other countries, like the US, health care is funded by public and private insurance plans. Depending on your own personal financial needs, costs of a serious health care issue might be funded through employer benefit plans, the Medicaid program, Medicare, or private insurance plans. For those still left with large expenses, most medical facilities will establish a long-term payment plan for the remaining balance.
Will I be able to work full time with MTC?
Each case is different. Depending on when your cancer was discovered, the staging of the disease in your body, your general state of health outside of cancer, age, and many other factors, MTC can be a "small bump" on the road of life, or a major detour. Many MTC patients take short term disability leave from work during their initial treatment (which might include surgery, external beam radiation, and medications) to allow their body to heal and adjust to life without a thyroid, then return to work part time or full time, depending on their financial needs and speed of recovery. For others, it signals the time to retire, focus on their health, and enjoy some family time.
What is my life expectancy with MTC?
Again, each case is different. However, MTC is a cancer you can live with and manage. There are many MTC patients who are in their second decade of managing this disease. And as time continues, progress is being made on new treatments and methods of dealing with MTC. For a newly diagnosed patient, the most critical decision you will make affecting your prognosis and life expectancy will be choosing a treatment center. Going to an MTC Center of Excellence (see above) for you initial treatment, surgery and followup will give you the best opportunity for a long and healthy life.
Where can I find more information that has the facts about MTC? What are more sources of information about MTC that I can access online?
Why do I need Genetic testing/counseling?
Genetic testing is necessary for two reasons. First, a "germline" genetic test is needed to determine if the MTC was caused by a hereditary mutation in your family's gene pool. This test looks for a mutation in your blood cells that indicate that you inherited the disease, and will pass the tendency for the disease along to your offspring. People who test positive for a germline mutation are further evaluated to determine whether they have one of the forms of Multiple Endocrine Neoplasm (MEN2A or MEN2B), or Familial MTC. This determination will help the medical professionals determine how to move forward with advising, testing, and treating other members of your immediate family. There is good information in the MTC Guidelines (another document which is available in this library of documents) on how to proceed if you have one of the inherited forms.
The second reason for genetic testing... in fact, a separate test altogether, is testing for a somatic mutation. This is a mutation that occurs ONLY in the MTC Tumor itself, and is not passed along to relatives. This test is performed against tumor tissue, post-surgery (In the US, tumor tissue must be held for ten years in cold storage for further testing, if needed) and can indicate the level of aggressiveness, and potentially indicate which treatment option will best address your particular tumor.
What is my chance of a full recovery?
This is a tricky question with a lot of dimensions. Clearly the best case is where the disease is detected early, and has not escaped the thyroid. Typically this is the case for hereditary MTC families, where one person shows symptoms, gets diagnosed, and then others in the family get tested. Often, children are diagnosed with inherited MTC early enough that the thyroid can be removed before the cancer spread and they stand an excellent chance of not having any recurrence. On the other hand, most sporadic MTC patients are diagnosed late in the disease, after it has escaped the thyroid, gotten into the lymph system, and often spread to distant bone, liver, lung, or other sites. In these cases, the person may never (using today's medicine) be fully cured of MTC, yet can still lead a full and normal life. We have members on this site who are 30+ years past their initial diagnosis. Their disease is "managed" by periodic monitoring, and a combination of medicines, and occasionally invasive procedures like surgery or radiation to address a particular issue. Much of what determines your chance of living a normal life is your attitude and your willingness to accept the fact that you can live with and manage this disease.