According to the National Cancer Institute, there are over 56,000 new cases of thyroid cancer in the US each year, and the majority of those diagnosed are papillary thyroid cancer—the most common type of thyroid cancer. Females are more likely to have thyroid cancer at a ratio of 3:1. Thyroid cancer can occur in any age group, although it is most common after age 30, and its aggressiveness increases significantly in older patients. Approximately 1.2 percent of all men and women will be diagnosed with thyroid cancer during the course of their lifetime.
This article will highlight some common thyroid cancer signs and symptoms as well as thyroid cancer prognosis and treatments.
Visit our thyroid cancer Patients' Guide to Thyroid Cancer for complete information on thyroid cancer types, causes, diagnosis, and treatments.
In this Article
Thyroid cancer frequently presents without any symptom whatsoever. When a symptom does present, the most common symptom is a lump in the neck. Less commonly, patients may have symptoms including hoarseness or change in voice. Symptoms of pain are very uncommon except in inflammatory conditions of the thyroid and the rarer of thyroid cancers called medullary thyroid cancer.
Although as many as 75% of the population will have thyroid nodules, the vast majority are benign. Young people usually don't have thyroid nodules. However, children and adolescents with thyroid nodules are most commonly benign, but the overall risk of thyroid cancer is markedly higher than in the adult population. As people age, they are more likely to develop a thyroid nodule. By the time we are 80 years of age, 90% of us will have at least one thyroid nodule.
Fewer than 1% of all thyroid nodules are malignant (cancerous). Thyroid nodules are most commonly identified due to routine physical examination or xray studies obtained for other reasons. The below MRI study was obtained for a patient complaining of neck pain following a motor vehicle accident. The red arrow points to a right thyroid mass (the right and left sides are reversed in xrays) which was confirmed to be papillary thyroid cancer by ultrasound guided needle biopsy.
You can read more information about thyroid nodules and their potential to be malignant in our articles below:
Talk to your doctor about any questions you have about thyroid cancer signs and symptoms.
There are 4 main types of thyroid cancer, and some are more common than others.
Thyroid cancer type and incidence:
Most thyroid cancers are very curable. In fact, the most common types of thyroid cancer (papillary and follicular thyroid cancer) are the most curable. In younger patients less than 50 years of age, both papillary and follicular cancers have a more than 98% cure rate if treated appropriately. Both papillary and follicular thyroid cancers are typically treated with at least complete removal of the lobe of the thyroid gland that harbors the cancer. A thyroid gland that has a thyroid cancer nodule within it and has multiple other nodules in both sides of the thyroid or when the cancer has spread to lymph nodes in the neck, is a clear indication for complete removal of the thyroid gland.
Only expert thyroid surgeons should perform thyroid surgery for nodules that may be cancers or patients with known thyroid malignancy. When expert evaluation of patients with thyroid nodules and cancers combined with expert thyroid surgery provides patients with the best outcomes.
The bottom line is that most thyroid cancers are papillary thyroid cancer, and this is one of the most curable cancers of all cancers. More than 98% of patients with papillary thyroid cancer remain alive after five years. Unfortunately, nearly 11% of patients with papillary thyroid cancer continue to have thyroid cancer following their initial thyroid cancer surgery. The most important thing for a patient with a new diagnosis of thyroid cancer is to not be in a rush, take a deep breath, and seek evaluation and care by thyroid cancer experts. This video for newly diagnosed thyroid cancer patients addresses the most common concerns.
Medullary thyroid cancer is significantly less common but has a worse prognosis. Medullary cancers tend to spread to large numbers of lymph nodes very early on and therefore require a much more extensive operation than the more localized thyroid cancers, such as papillary and follicular thyroid cancer. Extensive means more thorough and a wider or broader area. However, in almost all expert thyroid surgery, all major nerves, blood vessels, and muscles are spared!
Medullary thyroid cancer may also be a genetically inherited cancer and special testing and counseling is indicated for patients with medullary thyroid cancer to determine whether there is a family risk associated with the cancer.
Medullary thyroid cancer requires complete thyroid removal plus a dissection to remove the lymph nodes of the front and and often along the sides of the neck.
The least common type of thyroid cancer is anaplastic thyroid cancer, which has a very poor prognosis. Unless diagnosed early and found during a thyroidectomy, most cases of anaplastic thyroid cancer lead to a rapid and untimely death. Anaplastic thyroid cancer tends to be found after it has spread, and is one of the most incurable cancers known to mankind. Note: Chief Justice William Rehnquist had anaplastic thyroid cancer. You can read about anaplastic thyroid cancer in our in-depth article.
The only chance for cure, today, in anaplastic thyroid cancer is when the complete removal of the cancer can be obtained and there is no evidence of spread to other sites in the body (distant spread). This situation is rarely found. Anaplastic thyroid cancer patients require chemotherapy and radiation therapy unlike other types of thyroid cancer. New evolving therapies show some promise in these most aggressive cancers.
Thyroid cancer is unique among cancers. In fact, thyroid cells are unique among all cells of the human body. They are the only cells that have the ability to absorb iodine. Iodine is required for thyroid cells to produce thyroid hormone, so they absorb it out of the bloodstream and concentrate it inside the cell.
The most common thyroid cancers are made up of cells that retain this ability to absorb and concentrate iodine. This provides a perfect "targeted" strategy.
Radioactive Iodine is given to the patients with certain types of thyroid cancers called “differentiated thyroid cancers” following complete removal of their thyroid gland. These differentiated thyroid cancers include the most common thyroid cancers of papillary thyroid cancer and follicular thyroid cancers. If there are any normal thyroid cells or any remaining thyroid cancer cells in the patient's body (and any thyroid cancer cells retaining this ability to absorb iodine), then these cells will absorb and concentrate the radioactive "poisonous" iodine.
Since most other cells of our bodies cannot absorb the toxic iodine, they remain unharmed. The thyroid cancer cells, however, will concentrate the poisonous radioactive iodine within themselves and the radioactivity destroys the cell from within—no sickness, hair loss, nausea, diarrhea, or pain. Some normal cells such as your saliva glands, tear glands, breast tissue and bone marrow also will absorb some iodine and receive some potential risk of damage.
Less than twenty percent of patients with papillary or follicular thyroid cancer need or may benefit from radioactive iodine therapy. Indications for radioactive iodine treatment are based on findings at the time of the operation and final review of the microscopic findings of cancer. Papillary and follicular thyroid cancers which have spread outside of the thyroid gland itself spread to lymph nodes, or grown into blood vessels are reasons to treat with iodine therapy. Without such findings, radioactive iodine is not indicated.
Patients with medullary thyroid cancer do not need iodine therapy because medullary cancers never absorb the radioactive iodine. Newer targeted therapies have been developed for medullary thyroid cancer and have been shown to be beneficial when medullary thyroid cancers have spread to distant sites.
Small isolated papillary and follicular thyroid cancers are often cured with simple (complete) surgical therapy alone. This varies from patient to patient and from cancer to cancer. This decision will be made between the surgeon, the patient, and the referring endocrinologist. Remember, a single dose of radioactive iodine therapy is extremely safe. If you need it, take it.
The entire thyroid cancer must be surgically removed sometimes with just partial removal of the thyroid gland or total removal of the thyroid gland. With the use of high-resolution ultrasound before your operation and by expert inspection by your surgeon during your operation, the lymph nodes in the neck are examined to see if lymph nodes also need to be removed.
If you have been diagnosed with thyroid cancer, your doctor will create a thyroid cancer treatment plan for you—The first is a comprehensive evaluation of your thyroid and neck with high-resolution ultrasound and possible additional fine needle aspiration biopsy. The second step is almost always surgery including some type of thyroidectomy. Other thyroid cancer treatments such as radioactive iodine are not commonly required. More aggressive thyroid cancers may incorporate a combination of other thyroid cancer treatments beyond surgery and radioactive iodine.