City of Hope
’s comprehensive approach to thyroid cancer encompasses sophisticated diagnostic techniques and leading-edge surgical, radiotherapy and chemotherapy treatments for all types of thyroid cancers. City of Hope also employs new experimental therapies, which may not be available elsewhere, to fight advanced, aggressive thyroid cancers.
Thyroid cancer patients at City of Hope receive treatment from a coordinated, multidisciplinary team of surgeons, oncologists, endocrinologists, radiation oncologists, nurses, supportive care specialists and others, ensuring the highest possible standard of care.
Thyroid cancer occurs when malignant cells in the thyroid proliferate uncontrollably, forming tumors. Typically, thyroid cancer, in its most frequently-occurring forms, has an excellent prognosis with very high five-year survival rates and many patients are cured outright. Other forms of the disease may be highly aggressive and less responsive to therapy. Thyroid cancer has many forms, and there are significant differences between them in terms of risk factors, diagnostic tests and treatment options.
Understanding Your Thyroid
The thyroid is a small, butterfly-shaped gland located at the base of the throat near the trachea that produces thyroid hormones made by follicular cells. Thyroid hormones regulate metabolism
and calcitonin, which is made by parafollicular cells, or C-cells. Calcitonin regulates the body’s calcium levels.
Thyroid Hormone Levels: Too Much, Too Little and Just Right
Hypothyroidism refers to having too little thyroid hormone. If you are hypothyroid, your metabolism is slow, and you may experience weight gain, fatigue, depression, dry, itchy skin, dry, coarse and/or thinning hair, increased menstruation (heavier flow and/or more frequent periods), infertility and constipation. You feel generally sluggish, and may also feel cold frequently, particularly in the extremities.
Hyperthyroidism refers to an overactive thyroid, that is, one which produces too much thyroid hormone. The metabolism is abnormally fast and, as might be expected, the symptoms of hyperthyroidism are the polar opposite of hypothyroidism. They include: weight loss (despite a normal appetite), sweating, decreased menstruation, nervousness, insomnia, hand tremor, thinning skin, fine, thinning hair, rapid heartbeat and more frequent bowel movements or diarrhea.
When your thyroid hormone levels are normal, this is called euthyroid. Many patients diagnosed with thyroid cancer are euthyroid.
Nodules and Goiters
A thyroid nodule is a lump that develops in the thyroid. Depending on its size, it may be palpable or visible as a swelling in the neck. Most thyroid nodules are benign, but a small percentage are malignant.
The term “goiter” simply refers to an enlargement of the thyroid, which may be diffuse or nodular. Many goiters are multinodular as opposed to a solitary nodule. Goiters can occur in hyperthyroid, hypothyroid and euthyroid patients and generally develop as a result of increased TSH levels.
Types of Thyroid Cancer
•Papillary thyroid cancer is the most common type of thyroid cancer, accounting for over 80 percent of cases. It is usually slow-growing, localized to the thyroid, well-differentiated and has an excellent prognosis with high survival rates.
•Follicular thyroid cancer, as the name implies, originates from follicular cells. It is also usually slow-growing, localized to the thyroid. Follicular thyroid carcinoma has a good prognosis with high survival rates.
•Hurthle cell cancer is a type of follicular carcinoma in which a specific kind of cell (the Hurthle cell) is predominant in the tumor. Hurthle cell cancers are slightly more aggressive than other follicular carcinomas. They are less likely to take up radioiodine, which is significant because radioiodine ablates (destroys) residual thyroid tissue, and is thus an important treatment modality. They are also more likely to have nodal metastases (spread to neighboring lymph nodes).
•Anaplastic thyroid cancer is a type of follicular carcinoma that is thought to originate from well-differentiated papillary or follicular cancers through a process called dedifferentiation.
•Medullary thyroid cancer develops in the C-cells of the thyroid. More than any other type of thyroid cancer, medullary thyroid cancer has a well-established genetic component, with a sizable proportion of cases thought to be an inherited form of the disease.
•Thyroid lymphoma cancer originates from lymphoid tissue in the thyroid (as opposed to carcinomas, described above, which develop from epithelial cells). It is very rare, and often develops in patients who have a history of chronic thyroiditis. It is often treated similarly to other forms of non-Hodgkin lymphoma.
-Age and Sex: Patients with thyroid cancer are more likely to be female (three times more likely than males) and over 45 years of age. Anaplastic thyroid cancer almost always occurs in patients over 60. In evaluating whether a thyroid nodule may be malignant, a malignant nodule is much more likely if the patient is male and under the age of 20.
-Race: Caucasians are more likely than African-Americans to develop thyroid cancer.
-Childbearing Age: Women who have their last pregnancy after age 30 are at higher risk.
-Previous goiter/benign thyroid nodule
-Family history of medullary thyroid cancer (either FMTC or the MEN syndromes)
-Family history of multinodular goiter
-Family history of colon growths (Gardner’s syndrome/familial adenomatous polyposis, or FAP)
-Having Cowden’s disease (a rare inherited disorder)
-Iodine deficiency or excessive iodine intake
-Radiation exposure: this can be from prior radiotherapy treatment for other forms of cancer, exposure to atomic testing or nuclear power plant accidents or other occupational exposure. In addition, doctors used to routinely administer X-ray treatment to the head and neck area for conditions such as acne, fungal infections of the scalp and enlarged tonsils. This also was a significant cause of unnecessary radiation exposure.