Follicular Thyroid Cancer Surgery

Follicular thyroid cancer surgery is introduced here. The correct operation depends upon the follicular thyroid cancer, patient evaluation, and surgeon’s expertise. What is most important, is that all of the follicular thyroid cancer is removed from the neck in the initial surgery! That surgery can frequently be a minimally invasive surgery with a small incision about an inch in length in the lower front of the neck. But that is not really the point. The issue is all of the follicular thyroid cancer must be effectively removed at the initial surgery. The problem is that both the patient and the surgeon may not know that the thyroid mass is a follicular thyroid cancer until after the surgery is completed. Still, an expert thyroid cancer surgeon is necessary to accomplish the right surgery from the beginning independent of the timing of the diagnosis (which will be after you have recovered from the surgery)!

For follicular thyroid cancer (and all of the different types of follicular thyroid cancers that exist within this group), surgery, by far, is the most common first treatment. In fact, follicular thyroid cancer surgery is not only the first treatment but is commonly the only treatment that may be indicated. It is critical that a highly experienced surgeon and the right surgery is obtained the first time. Follicular thyroid cancer surgery should only be done by expert surgeons. By choosing the right surgeon and surgery, you are cured. The wrong choice may lead to repeated surgeries, complications, and even worse! Be well aware, that you may not know that you have a follicular thyroid cancer. You may have been told that you have a follicular lesion or similarly, a follicular neoplasm (means “new growth”). But the surgery you will require for these non-specific diagnoses from FNA, still needs to be a surgery that addresses the complete removal of your follicular thyroid cancer.

Thyroid surgery was one of the first ever described surgeries in medicine, but early on it wasn't very pretty or safe. Over the past 100 years, thyroid surgery has evolved into its current state of the art by some of the most recognized names in surgical history. Today, in skilled hands, follicular thyroid cancer surgery may be considered an art form in its own right.

Follicular thyroid cancer surgery must be considered in several different lights when you think about the neck. Surgery of the thyroid gland itself and surgery for the lymph nodes of the neck. The basic concept is however very simple, remove all of the cancer.

Follicular Thyroid Cancer can be approached by three basics types of thyroid gland surgery: What are they and what is right for me?
  • One is removal of about half of the thyroid gland called thyroid lobectomy.
  • The other is removal of all of the thyroid gland and is called total thyroidectomy.
  • The third type of thyroidectomy is called a subtotal thyroidectomy where almost all of the thyroid gland is removed
(Editors note: For the more favorable pathologic types of follicular thyroid cancer such as follicular thyroid neoplasm or uncertain malignant potential and follicular thyroid cancer with minimal ( a small focus of capsule invasion), a thyroid lobectomy is adequate treatment. It must be taken in the light that the patient will not be able to monitor their thyroglobulin levels or receive radioactive iodine….both which may be totally appropriate for these diagnoses of follicular thyroid cancer.

Thyroid Lobectomy

In this surgery, about half of the thyroid gland is removed. A small incision in the lower neck is required which is about an inch in length unless the thyroid mass requires a longer length to allow it to be "delivered". All of the critical structures on the side of the removed thyroid lobe are maintained including both parathyroid glands (the glands that control the calcium) and the nerves that provide movement and sensation to the voice box. The lymph nodes along the side and beneath the thyroid gland are also examined during this surgery to make sure that they are not cancerous as well. Editors note: A thyroid lobectomy is generally not recommended when there are nodules present in both sides of the thyroid gland (both lobes possessing nodules).

  • A very effective surgical treatment for small to intermediate size ( up to 4 cm or 1.75 inch) follicular thyroid cancers
  • Small cosmetic incision design
  • Essentially little to no risk of hypoparathyroidism (low blood calcium)
  • Outpatient surgical procedure
  • Return to normal aerobic activities and daily functions in 24 hours.
  • No heavy lifting for three weeks
  • Remaining thyroid tissue facilitates ease in thyroid hormone regulation.
  • The follicular thyroid cancer cannot be effectively monitored by measuring Thyroglobulin levels.
  • Only one nerve to the voice box is even at theoretical risk of injury.
Follicular Thyroid Cancer Surgery: Potential reasons to consider lobectomy (removing only half of the thyroid gland) include the following:
  • The follicular thyroid cancer is less than 4cm and there is no evidence of abnormal lymph nodes on ultrasound or CAT scan
  • The patient desires an easy method to maintain their thyroid hormone blood levels following surgery. (Some patients are concerned about their ability to adequately control their hormone levels and sense of well being when they are totally dependent upon taking thyroid hormone pills)
  • The follicular thyroid cancer patient understands their thyroid cancer and accepts that the blood test for the blood marker for follicular thyroid cancer called thyroglobulin, will not be useful in their monitoring of their cancer since this protein is also produced by the remaining normal thyroid cells in the remaining thyroid tissue
  • The follicular thyroid cancer patient understands that radioactive iodine will not be used for the treatment of their cancer
  • The follicular thyroid cancer patient does not desire or accept radioactive iodine as a treatment option for their cancer. If lymph nodes are enlarged or show signs of cancer spread, they will be removed as well.

Total Thyroidectomy

In this surgery, the entire thyroid gland is removed. A small incision in the lower neck is required which is about an inch in length unless the thyroid mass requires a longer length to allow it to be "delivered". The length of a total thyroidectomy incision is no longer than an incision for a thyroid lobectomy. All of the critical structures on both sides of the thyroid are maintained including all four parathyroid glands and all four nerves that provide movement (recurrent laryngeal nerves) and sensation to the voice box (superior laryngeal nerves). The lymph nodes along the side and beneath the thyroid gland are also examined during this surgery to make sure that they are not cancerous as well.

Potential reasons to consider removing the entire thyroid gland (total thyroidectomy):

  • The follicular thyroid cancer is large (more than 4 centimeters or 1.75 inches
  • The follicular thyroid cancer appears to have extended outside of the surface of the thyroid gland (called its capsule)
  • The follicular thyroid cancer has spread to the lymph nodes underneath the thyroid gland (called central compartment lymph nodes [also called Level VI or VII lymph nodes] of the neck)
  • The follicular thyroid cancer has spread to lymph nodes along the side of the neck (called lateral neck lymph nodes)
  • The follicular thyroid cancer has spread to distant sites outside of the neck (most commonly the lungs, bones, or liver)
  • The follicular thyroid cancer patient with a small thyroid cancer, does not accept the potential of another surgery to remove the remainder of the thyroid gland if a new thyroid cancer should develop within the remaining thyroid tissue.

Follicular Thyroid Cancer Surgery for Central Compartment Lymph Nodes (the lymph nodes beneath and surrounding the thyroid gland, breathing tube (trachea) and swallowing tube (esophagus)

The removal of the lymph nodes of the central neck can be performed initially when the thyroid gland is removed in the treatment of follicular thyroid cancer (see total thyroidectomy and central compartment dissection) or following the initial surgery in the less common circumstances when follicular thyroid cancer recurs or persists. The central compartment lymph node surgery spares all critical structures including the nerves to the voice box and all parathyroid glands not directly involved by cancer. Central compartment dissection extends from the carotid arteries on both sides of the neck, below to the blood vessels of the upper chest, and above to where the blood vessel of the upper portion of the thyroid gland begins off of the carotid artery (called the superior thyroid artery).

  • In follicular thyroid cancer, the central compartment lymph nodes are at risk of containing cancer in up to 50% of patients. That risk increases with the size of the follicular thyroid cancer. Even prior to surgery, most central compartment lymph nodes can be well examined with high quality ultrasound to determine if they are cancerous. Here, the arrow points to an abnormal lymph node seen on ultrasound next to the thyroid gland before surgery. Abnormal lymph nodes undergo fine needle aspiration (FNA) examination to determine whether cancer is present. Some lymph nodes which lay immediately underneath the thyroid gland cannot be seen until the time of surgery and required a skilled surgeon to identify them and can then be confirmed during the surgery by a process called frozen section pathology
  • If follicular thyroid cancer is determined to be present in central compartment lymph nodes at any time in a patient's lifetime, an expert surgeon who does this surgery routinely is needed to remove the lymph nodes in the central compartment, on both sides) and spare the nerves to the voice box and the critical glands that control calcium (parathyroid glands).
  • In larger follicular thyroid cancers which are greater than one inch or have grown outside of the capsule of the thyroid, removal of the lymph nodes of the central compartment on the side of the cancer should be done routinely since:
    • The nerve to the voice box (recurrent laryngeal nerve) has already, by necessity from the thyroid surgery itself, been significantly identified along most of its course and another surgery on the same side would be more difficult because of scarring and this subsequent surgery would put the nerve to the voice box at high risk for injury.
    • The risk of microscopic lymph node metastasis is approximately 50%

Extended or Complicated Thyroidectomy

Follicular thyroid cancer may sometimes be more aggressive than ultrasound or CT imaging suggested prior to undergoing surgery. In these cases, an expert surgeon that recognizes those "more aggressive" intraoperative findings such as growth or extension of the cancer outside of the thyroid gland or invasion of the cancer into adjacent structures such as the nerve to the voice box (recurrent laryngeal nerve), breathing tube (trachea), voice box, or esophagus-must adapt the surgery to adequately address the complete removal of the cancer. Unfortunately, occasional thyroid surgeons are commonly unprepared to perform the appropriate surgery and a subsequent surgery for persistent disease will be required.

Follicular Thyroid Cancer Surgery For Spread of Cancer to Lymph Nodes Along The Side Of The Neck (anterolateral neck)

  • Just the presence of enlarged lymph nodes does not mean follicular thyroid cancer has spread and does not require additional surgery
  • A procedure called an anterolateral neck dissection (or modified neck dissection), in untreated patients, should only be performed in instances of ultrasound with fine needle aspiration confirmed follicular thyroid cancer spread to lymph nodes in the side of the neck
  • The follicular thyroid cancer anterolateral neck dissection is not the same neck dissection as for other cancers that occur in the neck. Follicular thyroid cancer spreads to particular areas of the neck called levels. Removing just some of the lymph nodes has been called "cherry picking" and is the wrong surgery! A follicular thyroid expert surgeon trained and experienced to perform modified neck dissections specifically for thyroid cancer is needed to prevent recurrent or persistent disease.
  • The anterolateral neck dissection, in skilled hands, spares all critical nerves, muscles, and blood vessels which are not directly involved with cancer (very rarely are critical structures involved by follicular thyroid cancers). It is an approximately 40 minute surgery that removes lymph nodes and fatty tissue.

Follicular Thyroid Cancer Surgery in Sites Other Than The Neck

Follicular thyroid cancer surgery is uncommonly proposed as a treatment approach when disease has spread to distant sites. Although surgery is not commonly proposed for distant spread of follicular thyroid cancer, consideration for surgery for distant disease is based upon the expert thyroid cancer team evaluation and considers the following issues:

  • Where is the follicular thyroid cancer distant disease located?
  • What are the risks and benefits of surgery?
  • Are there other sites of distant spread?
  • What follicular thyroid cancer treatments have already been used?
  • What were the outcomes of other treatments for the follicular thyroid cancer?
  • How fast is the follicular thyroid cancer growing?
  • What are the patient's treatment desires?
  • What are the other treatment options?
  • What is the follicular thyroid cancer pathologic type (what do the cells look like under the microscope?
  • What are the follicular thyroid cancer genetic mutations found?

Follicular Thyroid Cancer Robotic Surgery

Robotic surgery for the thyroid was developed largely in South Korea and brought to the United States several years ago as a "tool" in thyroid surgery. Its proposed benefits were to be the following:

  • Absent or less noticeable neck incisions
  • Improved visualization
  • Less Surgeon Fatigue

Although we have been trained and performed robotic thyroid surgery, the following is the reality of robotic thyroid surgery:

  • Incisions are tremendously longer but just not located on the front of the neck
  • In follicular thyroid cancer, it is a one sided surgery approach to a frequently required two-sided surgery!
  • The instruments used to perform the surgery are not as refined or delicate as the instruments used to perform the minimally invasive neck surgeries. (think of all the delicate structures that we have shown you here)
  • Multiple surgeons are required
  • The surgeon has no ability to
  • feel
  • in the neck. The fingers are the surgeon's third eye. Subtle changes in feel, hardness or extension of cancer can be totally unappreciated.
  • t is not minimally invasive by any measure. It is maximally invasive but just at a distance from where the surgery is focusing.
  • It is a much longer surgical procedure by any measure (the set up of the robot is longer than the average thyroid lobectomy).
  • It is an inferior surgical approach to manage follicular thyroid cancer
  • Unanticipated findings during surgery may not be able to be adequately addressed robotically.
  • It may be an acceptable surgical approach for clearly known benign thyroid surgery.

Most importantly, the ability to perform a surgery well is not an indication for a surgery!!! Robotic thyroid surgery is an inferior surgical approach in managing follicular thyroid cancer, any other type of thyroid cancer, or any thyroid lesion at risk of being a potential thyroid cancer.

Follicular Thyroid Cancer Treatment with Radioactive Iodine (RAI)

Follicular thyroid cancer, itself, is not an indication for RAI treatment. RAI treatment is a type of internal radiation therapy. RAI treatment was the first true "targeted therapy" developed in the treatment of cancer. The follicular thyroid cancer patient swallows a radioactive iodine form of iodine called iodine 131 (I-131) in a liquid or pill (capsule) form. The RAI is absorbed through digestion and circulated throughout the body in bloodstream. Follicular thyroid cancer cells can pick up the radioactive iodine wherever they are located in the body.

If you had a follicular thyroid cancer, 25 years ago, you would have almost certainly been treated with surgery and RAI. Today, only approximately 20% of all follicular thyroid cancer patients undergo post-0perative RAI treatment. RAI therapy is primarily beneficial only when the follicular thyroid cancer patient has undergone a total thyroidectomy (complete removal of the thyroid gland) for their follicular thyroid cancer.

Follicular thyroid cancer should only undergo RAI treatment (therapy) in instances where the risk of the follicular thyroid cancer coming back is greater than the potential risks of RAI therapy itself. In follicular thyroid cancer treatment, there is no urgency for the rapid delivery of RAI. RAI can be given as early as 4-5 weeks following total thyroidectomy but can be delayed for months or even years following surgery.

Follicular thyroid cancer indications for RAI treatment include:
  • Follicular thyroid cancer evidence of invasion (or extension) outside of the thyroid gland capsule (called soft tissue extension)
  • Follicular thyroid cancer that has spread to at least two lymph nodes in the neck (in any area of the neck)
  • The follicular thyroid cancer team desire to destroy any additional thyroid tissue
  • Follicular thyroid cancer that has spread to distant sites (lungs, bones, and liver)
  • The follicular thyroid cancer takes up the iodine

Preparation for Radioactive Iodine Treatment

Follicular thyroid cancer patients must be taken off of levothyroxine thyroid hormone (T4 hormone) for a minimum of four weeks, taken off of liothyrionine thyroid hormone (T3 hormone) for a minimum of two weeks, or receive a medication which is TSH (which is a pharmaceutical production of the Thyroid Stimulating Hormone [TSH] produced as a recombinant protein which is identical to the TSH normally produced by the pituitary gland). Additionally, follicular thyroid cancer patients must be on a low iodine diet for a minimum of four weeks to starve their body of iodine. Those patients which have undergone CAT scans with intravenous contrast must wait until their blood iodine levels have been adequately decreased (usually at least two months). Note, a desire to treat with radioactive iodine should never prevent the use of necessary CAT scans for the evaluation of a follicular thyroid cancer patient.

The potential risks of RAI treatment include:

  • Dry mouth and or eyes
  • Narrowing of the drainage duct of the eye's tears leading to excessive tearing down the cheek
  • Decreased production of blood cells by the bone marrow (with very high RAI doses)
  • Swelling in your cheeks from inflammation or damage to the saliva producing glands (the spit glands)
  • Short term changes to taste and smell (usually resolve in 4-8 weeks)
  • Lowered testosterone levels in males (usually resolves within the first year)
  • Change in periods (menstruation) in women (usually resolves within the first year)
  • Second tumors (these are rare and can be discussed with your thyroid cancer treatment team)

Follicular Thyroid Cancer Treatment With RAI (Radioactive Iodine): How and How Much Treatment?

Follicular thyroid cancer guidelines for post operative treatment with radioactive iodine were last updated in the American Thyroid Association 2015 edition. After your doctor has prepared your body for RAI by either stopping your use of thyroid hormone pills or giving injections of recombinant TSH (Thyrogen), they may choose to give you a small dose of RAI and perform a special nuclear scan called a Thyroid Cancer Uptake Study. In this scan, the image will determine if there is any evidence of iodine uptake in the body. Approximately 90% of patients will have some uptake of iodine following a total thyroidectomy. Follicular thyroid cancer is not the only reason that iodine can be taken up by tissue. One such issue is retained thyroid tissue. How much retained thyroid tissue is related to the thoroughness of your thyroid surgeon in performing a total thyroidectomy. The amount of RAI chosen to treat the follicular thyroid cancer is based upon:

  • The level of thyroglobulin while the TSH is elevated for the scan (this is called a stimulated thyroglobulin)
  • The percent uptake of RAI in the Thyroid Cancer Uptake Scan
  • The follicular thyroid cancer locations of disease (uptake)
  • Prior RAI treatment doses

As an alternative to a thyroid cancer uptake study of a small dose of RAI, some doctors may choose to give you their prescribed dose of RAI as a definitive treatment. Following either of the above approaches to treat a follicular thyroid cancer with RAI, a scan is obtained following the therapeutic dose in 48 to 72 hours to determine the location and percent uptake of the radioactive iodine. The strength of radioactive iodine is described in millicuries. The follicular thyroid cancer treatment dose of radioactive iodine ranges from about 30 millicuries to approximately 150 millicuries. Low risk follicular thyroid cancers and eradication of small amounts of retained thyroid tissue are treated with lower doses of RAI in the 30-50 range. Intermediate risk follicular thyroid cancers such as patients above 50 years of age with lymph node spread are treated in the middle ranges. Follicular thyroid cancers with high risk features or distant spread of disease are treated with higher doses in the 150 millicurie range.

Follicular thyroid cancers can also be treated with radioactive iodine based upon a method called dosimetry. This is a radiation physics determination utilizing complex mathematical methods to determine the actual dose of radiation that will be delivered to a particular area of follicular thyroid cancer. In some circumstances, dosimetry can allow much higher doses of radioactive iodine to be prescribed when follicular thyroid cancers effectively take up the treatment. Follicular thyroid cancers, however, rarely require dosimetry for definitive treatment.

Thyroid Hormone Suppressive Therapy for Follicular Thyroid Cancer

Thyroid hormone is a necessary hormone for life. The thyroid gland normally produces thyroid hormone to adequate levels. The amount of thyroid hormone produced by the body is strictly controlled by a portion of the brain called the pituitary gland. When the body has too little thyroid hormone, the pituitary gland senses the low levels and produces TSH (thyroid stimulating hormone). When thyroid hormone levels are elevated (too high), the pituitary does the opposite and lowers its production of TSH. This is called an endocrine feedback loop.

Most follicular thyroid cancer cells and all normal thyroid cells have a site on the surface of the cell that can stimulate their growth. This site is called a "receptor" and when stimulated by TSH (thyroid stimulating hormone) in normal thyroid cells it causes increased production of thyroid hormone. In follicular thyroid cancer cells, this same TSH receptor can stimulate the growth of these cancer cells. Obviously, it is undesirable concept to have TSH stimulate follicular thyroid cancer cells to grow. Therefore the goal in the follicular thyroid cancer patient is to keep TSH levels low. So how is this done?

When follicular thyroid cancer patients take thyroid hormone pills, the body does not tell the difference between this medication and what the thyroid gland produces. The more thyroid hormone circulating in your body causes the TSH production to drop. Therefore, follicular thyroid cancer patients are usually given thyroid hormone to decrease TSH levels to prevent the growth of the cancer cells. Giving thyroid hormone to follicular thyroid cancer patients is called thyroid hormone suppressive therapy when the goal is to decrease the pituitary production of TSH. Follicular thyroid cancer patients that have thyroid suppressive therapy will have TSH levels that are below the "normal range". To those that are caring for follicular thyroid cancer patients but unfamiliar with the concept of thyroid suppressive therapy, they may mistake the dose of thyroid hormone for being "too high". Thyroid suppressive therapy is a delicate balance between elevated but not "too high" thyroid hormone doses. It is therefore important that only your skilled follicular thyroid cancer specialist manage your thyroid hormone. But it is also important that communication be open between your follicular thyroid cancer specialist and those that are caring for your primary care needs.

External Beam Radiation Therapy for Follicular Thyroid Cancer

Follicular thyroid cancer treatment with external beam radiation therapy is not commonly required or indicated. The planning and implementation of radiation therapy is beyond the goals for this website. However certain principles must be emphasized. Radiation therapy is not a substitute for incomplete surgery. What is meant by that is all the follicular thyroid cancer in the neck must be completely and effectively removed. Whenever feasible, follicular thyroid cancer patients should be reduced down to microscopic remaining neck disease, at most, also sparing voice box and swallowing tube function. Radiation therapy should not be given as a substitute for incomplete surgery. As a general rule, choosing to treat a follicular thyroid cancer with external beam radiation is a commitment that the surgeon believes that no meaningful re-operation will be feasible in the future and therefore radiation therapy is required to help control the follicular thyroid cancer (microscopic disease) remaining in the neck. In these circumstances, external beam radiation therapy is quite effective. Follicular thyroid cancer radiation therapy is also associated with significant short term and long term complications and effects that should not be taken lightly.

Follicular Thyroid Cancers Indications for External Beam Radiation Therapy generally occur in patients above 50 years of age and include Follicular thyroid cancers which:
  • Invade (grow into) the voice box (larynx), breathing tube (trachea) or swallowing tube (esophagus)
  • Directly grow into the skin or deep structures in the neck
  • Invade the tissues underneath the breast bone (sternum)
  • Are deemed unable to undergoe another surgery if their cancer should return.
  • Have spread to the spinal column and risk the spinal cord itself
  • Have spread to the brain
  • Have spread to bone and are causing pain or growth would place the bone at risk for fracture.

Follicular Thyroid Cancer Treatment for Persistent or Recurrent Disease:

Follicular thyroid cancer treatment for recurrences (cancer that has come back) or persistence (cancer that remains after initial therapy) depends mainly on where the cancer is, although other factors may be important as well. The recurrence may be found by either thyroglobulin blood tests or imaging studies such as ultrasounds, radioiodine scans, CAT scan or PET imaging.

If there is concern that the follicular thyroid cancer has come back in the neck, an ultrasound-guided biopsy is first done to confirm that it is really cancer. Then, if the follicular thyroid cancer appears to be resectable (removable), surgery is often used. The extent of surgery would depend upon the location or locations of the persistent or recurrent follicular thyroid cancer and the prior surgeries and quality of surgeries that the patient has undergone. The sections of central compartment surgery and lateral neck dissection have been written for you and are appropriate for persistence or recurrent follicular thyroid cancer in either of those locations. We have examples of surgeries for just these types of circumstances for you to watch. Follicular thyroid cancer surgery very effectively manages neck disease, sparing function and cosmetic appearance but should only be performed by very high volume and experienced follicular thyroid cancer surgeons. We have publications establishing our ability to control follicular thyroid cancer recurrences or persistence in the neck approaching 98% in both (either) of these areas of the neck lymph nodes.

Persistent or recurrent follicular thyroid cancer in residual thyroid tissue is much more concerning for the potential for the cancer to extend directly into the breathing tube or voice box. Only the most skilled and experience thyroid cancer surgeons should manage such circumstances. The purpose of this specific follicular thyroid cancer surgery is to maintain vocal and swallowing function, parathyroid function, and airway control. These are the most complicated and complex of all thyroid surgeries.

If the follicular thyroid cancer shows up on a radioiodine scan (meaning the cells are taking up iodine), radioactive iodine (RAI) therapy may be used, either alone or with surgery. If the follicular thyroid cancer does not show up on the radioiodine scan but is found by other imaging tests such as a, ultrasound, CAT scan, or PET scan, the follicular thyroid cancer is termed non-radioiodine avid. The follicular thyroid cancer treatment will be based upon interdisciplinary evaluation, disease locations and extent of disease.

Targeted Therapy and/or Chemotherapy

For follicular thyroid cancer patients who have spread of their cancer to several places outside of the neck area and RAI and other treatments are not helpful or the cancer sites are getting bigger, new therapies have been developed and approved by the FDA (Food and Drug Administration). Although these FDA approved follicular thyroid cancer targeted medications have been shown to be effective, none of these treatments are curative. Skilled physicians in prescribing these medications are required because of the necessity for close monitoring of symptoms, toxicities, and monitoring of the patient's follicular thyroid cancer.

The two approved targeted therapies (medication pills) in the management of follicular thyroid cancer are Lenvima and Sorafenib. These medications are taken by mouth and frequently cause weight loss, fatigue, muscle wasting, hand and foot pain, changes in blood pressure and skin symptoms. The toxicities are directly related to the dose and frequency the medication is taken. Again, these medications cannot be taken indefinitely and do not cure the follicular thyroid cancer.

Follicular thyroid cancer chemotherapy is rarely indicated except when used in combination with radiation therapy for the worst of the worst types of thyroid cancers growing into the breathing tube or swallowing tube. Experimental therapies such as new targeted therapies, immune therapy based treatments, and other novel approaches for follicular thyroid cancer should be developed in institutions directed and capable of performing such investigational studies.