What is Thyroid Cancer?
There are 20,000 new cases of thyroid cancer diagnosed every year in the United States. When thyroid cancer occurs the thyroid gland, which supplies the hormones that control the metabolism for the whole body, becomes overactive in its production of cells. There are well-differentiated kinds of thyroid cancer, and typically, the most common forms have the best prognosis. The less common forms of thyroid cancer tend to be extremely aggressive. Usually, thyroid cancer is treated with a combination of thyroid suppression drugs, radioactive iodine treatment, and surgery. Surgical oncologists, who have a specialized proficiency in treating the thyroid, are recommended for the management of these patients.
Types of Thyroid Cancer
There are several differentiated kinds of thyroid cancer tumors. Thyroid cancer is most common after the age of thirty but can be diagnosed at any age. Additionally, thyroid cancer is three times more common in women than in men. The differentiated types of thyroid cancer tumors include:
Papillary Tumors—These make up 78% of all thyroid cancers. They metastasize (spread) most frequently to the lungs and bones and usually spread to the lymph glands in the neck as well. Papillary tumors almost never spread to distant organs.
Follicular (Hurthle cell) Tumors—This is the second most common thyroid cancer and often metastasizes (spreads) to distant organs (lungs, bones, brain, liver, bladder, skin). Follicular tumors move to lymph glands less often than papillary tumors. Follicular tumors most often emerge between the ages of 40-60, and if treated correctly, have a cure rate of 97% or higher.
Medullary Tumors—These metastasize (spread) to the lymph nodes in early stages. After surgery, calcitonin hormone levels are taken every 4-6 months to look for a recurrence of the disease. If the cancer has not moved outside of the thyroid gland, the survival rate is 90%. The survival rate is 70% if the condition has metastasized to the lymph glands in the neck and 20% if the cancer has affected distant organs.
Primary Thyroid Lymphoma (PTL)—This is a rare form of thyroid cancer that develops from blood cells called lymphocytes. PTL only comprises about 1-5 % of all thyroid cancers and 1-2% of all lymphomas outside of lymph nodes. The bulk of patients are diagnosed with non-Hodgkin’s lymphoma, but establishing the particular type of lymphoma is extremely important in treatment selection and prognosis.
Anaplastic Cancer—This is the most rare and aggressive form of thyroid cancer. Three years following diagnosis and treatment the survival rate for patients is only 10%. The tumors grow quickly, and over 90% of them metastasize (spread) to the lymph glands in the neck and to outlying organs. The average age of onset 65 years or older, and men are twice as likely as women to be diagnosed with anaplastic cancer. A tracheotomy (breathing tube placed in the neck) is often required to breathe, because the tumor blocks the airway by pressing down on the trachea (windpipe). This cancer must be identified early to increase the chance of survival, because it is typically low.
Another type of thyroid tumor is a thyroid nodule. There are a number of kinds, but over 95% of these nodules are benign (non-cancerous). Test must be performed, however, to distinguish between cancerous and non-cancerous nodules.
Fine Needle Aspiration Biopsy is the test that determines if a nodule is cancerous or benign. A needle is inserted into the thyroid nodule to take a sample of cells. These are then examined under a microscope to ascertain if the nodule is cancerous. If benign, a doctor may decide to just watch the thyroid nodule to make sure it does not increase in size or cause symptoms. Thyroid hormones may also be prescribed to slow down gland activity and stop more nodules from developing. If a nodule grows, another biopsy might be needed. If diagnosed as cancerous, surgery is often necessary to remove the nodule or nodules.
Risk factors that increase the chance of a thyroid nodule being cancerous include:
- Family history of thyroid cancer or thyroid cancer syndromes.
- Personal experience of radiation to head, neck, or upper body.
- Under the age of 20 or over the age of 70.
- Male gender.
- Nodules that are growing in size.
- Nodules that have a firm consistency.
- Swollen neck lymph nodes.
- Symptoms of hoarseness.
Why Have Surgery for Thyroid Cancer?
When diagnosed with a form of thyroid cancer, often surgery is necessary to remove the cancer and keep it from metastasizing (spreading).
Types of Surgery for Thyroid Cancer
Depending on the type and stage of cancer and the patient’s particular health, history, and case, one of several types of thyroid surgeries will be recommended. There are three different types of thyroidectomies (thyroid surgeries) that might be performed. A thyroidectomy is a surgery to remove all or part of the thyroid gland. The amount of the thyroid gland removed depends on the patient’s particular cancer and condition. The three types of thyroidectomy surgeries that are performed for treatment of thyroid cancer include:
Total Thyroidectomy—This surgery is the total removal of the thyroid gland for a patient with thyroid cancer or large benign tumors. Thyroid hormone replacement medication will be needed following the removal of the whole thyroid gland.
Thyroid Lobectomy—For this procedure, one side (a lobe) of the thyroid gland is taken out for patients with just one thyroid nodule. Usually, thyroid hormone therapy is not needed after surgery, because the patient’s other lobe takes charge of the function of the whole thyroid gland.
Thyroid Lobectomy with Isthmusectomy—During this surgery, one side (a lobe) of the thyroid gland and the thyroid tissue that joins the two lobes (the isthmus) is removed. A larger portion of thyroid tissue is taken out than during a lobectomy.
Risks and Complications of Surgery for Thyroid Cancer
Usually, surgery to remove all of part of the thyroid gland involves a low amount of associated risks and complications. When surgery is performed to treat thyroid cancer, the surgeon will discuss the associated risks for the patient’s particular situation, but general complications related to any thyroid surgery include:
- Airway blockage due to bleeding.
- Indefinite weak or hoarse voice from laryngeal nerve damage.
- Hypoparathyroidism from injured parathyroid glands, which can cause inflated levels of phosphorus in the blood as well as:
- Hypocalcemia, which is atypically low blood calcium levels.
What to Expect Before Surgery for Thyroid Cancer
Depending on the particular cancer being treated, the surgical oncologist will give the patient very specific pre-surgery instructions.
Every case is different, so it is important to consult the surgeon for all medication, eating and drinking instructions before surgery to avoid complications or problems with anesthesia.
What to Expect During Surgery for Thyroid Cancer
A thyroidectomy typically takes several hours, but the length of the surgery depends on what type of thyroid surgery is being performed and the particular patient’s form of cancer being treated. The surgery is performed under general anesthesia, so the patient is unconscious the whole time. Contingent on the particular surgery being performed, either a small incision is made in the front of the neck or several small incisions are made under the arm. Then, based on the exact reason for surgery, either a portion or all of the thyroid gland is removed. Of course every individual case is different, but the general goal is for the surgical oncologist to remove all or as much cancerous cells/tissue as possible.
During the procedure, an advanced technological tool called Intraoperative Recurrent Laryngeal Nerve Monitoring can be utilized to keep from causing damage to the laryngeal nerve (voice box nerve), which is close to the site of surgery. The muscles of the vocal cords are attached to a computer by electrodes. The laryngeal nerve is continually monitored, and the technician will inform the surgeon if the nerve is unintentionally agitated.
What to Expect After Surgery for Thyroid Cancer
Following surgery, the patient will be moved to a recovery room to wake up. Once fully conscious, the patient will be relocated to a hospital room. There may be a drain under the neck incision, which is usually taken out the morning after the procedure.
After a thyroidectomy, it is normal for a patient to have some short-term neck pain and a weak or hoarse voice. This does not mean that any permanent injury to the laryngeal nerve exists, as these symptoms usually subside.
Patients can eat and drink normally after the surgery and most go home from the hospital within 24 hours after surgery.
The patient should discuss any activity restrictions with their physician. Usually, once a patient has recovered from the thyroid surgery itself, he or she can return to regular activities within a few weeks, but of course, when being treated for cancer, this varies and depends on the severity of the case.
If the whole thyroid is taken out (total thyroidectomy), the body is no longer able to produce thyroid hormone, so the patient must take a daily pill, which replaces the thyroid hormone thyroxine. This keeps the body from experiencing signs and symptoms of hypothyroidism. The physician will determine the amount of thyroid hormone replacement needed by blood tests.
Sometimes calcium supplements are needed temporarily following a total thyroidectomy if blood calcium levels drop too low (hypocalcemia). This side effect does not usually continue.
Radioactive Iodine is used following surgery to get rid of any thyroid cells that might be remaining in the body after the thyroidectomy. Four to six weeks after the surgery, a single radioactive iodine pill is taken. Thyroid cells are the only cells with the capacity to absorb iodine, so any surviving thyroid cells will absorb the radioactive iodine and be terminated. Radioactive iodine will not cause hair loss, nausea, or injury any other cells in the body.