Papillary Carcinoma and Papillary Carcinoma Variants

Stage I: Lobectomy (removal of only the affected side of the thyroid gland) may be an option if the patient is fairly young, the tumor is small (less than about 1 cm across), and there is no sign of cancer in the lymph nodes or the other thyroid lobe. Thyroidectomy is also an option to treat these cancers. Radioiodine treatment is sometimes used after thyroidectomy, but the cure rate with surgery alone is excellent. In the unlikely event of recurrence, radioiodine treatment can still be offered.

If the patient is younger than about 15 or older than about 45, or the tumor is larger, is growing outside the covering capsule of the thyroid gland, or there is obvious spread to lymph nodes, doctors prefer thyroidectomy, including the removal and microscopic examination of the lymph nodes. Radioiodine therapy is often used as well, especially if there are any signs of residual disease.

Regardless of the size of the cancer and type of operation (lobectomy or some type of thyroidectomy), thyroid hormone is given after surgery. If radioactive iodine treatment is planned, the start of thyroid hormone therapy may be delayed until the treatment is finished (usually about 6 weeks after surgery).

Some doctors recommend central compartment neck dissection (surgical removal of lymph nodes next to the thyroid). Although this operation has not been shown to improve cancer survival, it lowers the risk of cancer coming back in the neck area (local recurrence). It also makes it easier to accurately stage the cancer.

Stages II to IV: Most patients have a near-total thyroidectomy or total thyroidectomy with removal and microscopic examination of nearby lymph nodes. Sentinel lymph node biopsy is sometimes done, but this is not yet standard. Some doctors recommend central compartment neck dissection (surgical removal of lymph nodes next to the thyroid). Although this has not been shown to improve survival, it lowers the risk of local recurrence (cancer coming back in the neck area). It also makes it easier to accurately stage the cancer. If cancer has spread to other neck lymph nodes, a modified radical neck dissection (a more extensive surgical removal of lymph nodes from the neck) is often done.

Radioactive iodine therapy is often used to destroy any remaining thyroid tissue after surgery and to treat any undetectable cancer remaining in the neck or elsewhere in the body that takes up iodine. External radiation may be used for cancers that do not take up iodine. Thyroid hormone therapy is used as well.

Recurrent cancer: Treatment of cancer that comes back after initial therapy depends mainly on where the cancer is, although other factors may be important as well. If the cancer recurrence can be located and appears to be resectable (removable), surgery is often used. If the cancer shows up on a radioiodine scan (meaning the cells are taking up iodine), radioiodine therapy may be used, either alone or with surgery. If the cancer does not show up on the scan but is found by other imaging tests such as an MRI scan, external radiation may be used. Chemotherapy may be tried if the cancer has spread to several places (and radioiodine is not helpful), although doctors are still trying to find effective drugs for this disease. Another option is taking part in a clinical trial of newer treatments.

Follicular and Hürthle Cell Carcinoma

Stages I to IV: Most doctors recommend near-total or total thyroidectomy for these types of thyroid cancer. This surgery makes radioactive iodine treatment afterwards more effective. In rare cases, a lobectomy of the involved side of the thyroid may be done instead for small cancers. As with papillary cancer, some lymph nodes usually are removed and examined. If cancer has spread to lymph nodes, a central compartment or modified radical neck dissection (surgical removal of lymph nodes from the neck) may be done. Because the thyroid is removed, patients will need thyroid hormone therapy as well.

Radioiodine scanning is usually done after surgery to look for areas still taking up iodine. Spread to nearby lymph nodes and to distant sites can be treated by radioactive iodine. For cancers that don't take up iodine, external beam radiation therapy may help treat the tumor or prevent it from growing back in the neck.

Distant metastases may need to be treated with external beam radiation therapy or chemotherapy if they do not respond to radioactive iodine.

Recurrent cancer: The options for treating cancer that comes back after initial treatment are basically the same as they are for recurrent papillary cancer (see above).

Medullary Thyroid Carcinoma (MTC)

Most doctors advise that patients diagnosed with MTC be tested for other tumors that are typically seen in patients with the MEN 2 syndromes (see "What Are the Risk Factors for Thyroid Cancer?"), such as pheochromocytoma and parathyroid adenoma. 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. Regional lymph nodes are usually removed as well (central compartment or modified radical neck dissection). Thyroid hormone therapy is always given, since after total thyroidectomy the patient will not be able to make enough thyroid hormone to stay healthy. Although thyroid hormone therapy reduces the risk of papillary and follicular cancer recurrence, it does not reduce the likelihood of MTC recurrence.

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 reduce the chance for recurrence in the neck.

Recurrent cancer: Surgery, external radiation therapy, or chemotherapy may be needed to treat recurrent disease in the neck or elsewhere. Clinical trials of new treatments may be another option if standard treatments aren't effective.

Genetic testing in MTC: 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 -- seen in cases of familial MTC and the MEN 2 syndromes. If you have one of these mutations, it's important that family members (children, brothers, and sisters) be tested as well. Because almost all children and adults with positive genetic test results will develop MTC at some time, doctors generally agree that thyroidectomy to prevent MTC should be done soon after positive testing, even in children. Some would say especially in children, since some hereditary forms of MTC affect children and pre-teens. Total thyroidectomy can indeed prevent this cancer in carriers who have not yet developed it. Of course, this means that lifelong thyroid hormone replacement will be needed.

Anaplastic Carcinoma

Stage IV (note: all anaplastic thyroid cancers are classified as stage IV): Surgery may or may not be used to treat this cancer, because it is often widespread at the time of diagnosis. If the cancer is confined to the local area around the thyroid, which is rare, total thyroidectomy may be done. The goal of surgery is to remove as much cancer as possible in the neck area, ideally leaving no cancer tissue behind. Because of the way anaplastic carcinoma spreads, this is often difficult or impossible. Local spread to essential structures within the neck (the windpipe, arteries, etc.) is responsible for most deaths from this type of thyroid cancer.

External beam radiation therapy, alone or combined with chemotherapy, may be used:

• to treat the disease before surgery in order to increase the chance of complete tumor removal 
• after surgery to try to control any disease that remains in the neck 
• in cases where the tumor is too large or widespread to be treated by surgery

If the cancer is causing (or may eventually cause) trouble breathing, a hole (tracheostomy) may be placed surgically in the front of the neck to bypass the tumor and allow the patient to breathe more comfortably.

For cancers that have spread to distant sites, chemotherapy may be used, sometimes along with radiation therapy if the cancer is not too widespread. Clinical trials of newer treatments are an option as well.