Thyroid Cancer Symptoms, Diagnosis, and Treatments
According to the National Cancer Institute, there are about 56,000 new cases of thyroid cancer in the US each year, and the majority of those diagnoses 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. Thyroid cancer does not always cause symptoms; often, the first sign of thyroid cancer is a thyroid nodule.
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 Symptoms
- Types of Thyroid Cancer
- Thyroid Cancer Prognosis
- Overview of Typical Thyroid Cancer Treatment
Thyroid Cancer Symptoms
Some thyroid cancer signs and symptoms include a hoarse voice, neck pain, and enlarged lymph nodes. Although as much as 75% of the population will have thyroid nodules, the vast majority are benign. Young people usually don't have thyroid nodules, but as people age, they're more likely to develop a nodule. By the time we are 80, 90% of us will have at least one nodule.
Fewer than 1% of all thyroid nodules are malignant (cancerous). A nodule that is cold on scan (shown in photo above and outlined in red and yellow) is more likely to be malignant. However, the majority of these are benign as well. You can read more information about thyroid nodules and their potential to be malignant in our articles below:
- Introduction to Thyroid Nodules
- The Workup of Thyroid Nodules and the Role of Fine Needle Aspiration (FNA) Biopsy
- The Role of Thyroid Ultrasound and What It Means
Talk to your doctor about any questions you have about thyroid cancer signs and symptoms.
Types of Thyroid Cancer
There are 4 main types of thyroid cancer, and some are more common than others.
Thyroid cancer type and incidence:
- Papillary and/or mixed papillary/follicular thyroid cancer: ~ 80%
- Follicular and/or Hurthle cell thyroid cancer: ~ 15%
- Medullary thyroid cancer: ~ 3%
- Anaplastic thyroid cancer: ~ 2%
Thyroid Cancer Prognosis
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, both papillary and follicular cancers have a more than 97% cure rate if treated appropriately. Both papillary and follicular thyroid cancers are typically treated with complete removal of the lobe of the thyroid that harbors the cancer, in addition to the removal of most or all of the other side.
The bottom line is that most thyroid cancers are papillary thyroid cancer, and this is one of the most curable cancers of all cancers. Treated correctly, the cure rate is extremely high.
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 aggressive operation than the more localized thyroid cancers, such as papillary and follicular thyroid cancer.
This cancer requires complete thyroid removal plus a dissection to remove the lymph nodes of the front and sides of the neck.
The least common type of thyroid cancer is anaplastic thyroid cancer, which has a very poor prognosis. Anaplastic thyroid cancer tends to be found after it has spread, and it is incurable in most cases. Note: Chief Justice William Rehnquist had anaplastic thyroid cancer. You can read about anaplastic thyroid cancer in our in-depth article.
It is very uncommon to survive anaplastic thyroid cancer, as often the operation cannot remove all of the tumor. These patients often require a tracheostomy during the treatment, and treatment is much more aggressive than for other types of thyroid cancer.
Thyroid Cancer and Chemotherapy?
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.
Most thyroid cancer cells retain this ability to absorb and concentrate iodine. This provides a perfect "chemotherapy" strategy.
Radioactive Iodine is given to the patient with thyroid cancer after their cancer has been removed. 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 all other cells of our bodies cannot absorb the toxic iodine, they are unharmed. The thyroid cancer cells, however, will concentrate the poison within themselves and the radioactivity destroys the cell from within—no sickness, hair loss, nausea, diarrhea, or pain.
Most, but not all, patients with thyroid cancer need radioactive iodine treatments after their surgery. This is important to know. Almost all patients should have the iodine treatment if a cure is to be expected.
Patients with medullary thyroid cancer usually do not need iodine therapy because medullary cancers almost never absorb the radioactive iodine. Some small papillary thyroid cancers treated with a total thyroidectomy may not need iodine therapy as well, but for a different reason.
These cancers (medullary and some small papillary 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, radioactive iodine therapy is extremely safe. If you need it, take it.
Overview of Typical Thyroid Cancer Treatment
- Thyroid cancer is usually diagnosed by sticking a needle into a thyroid nodule or removal of a worrisome thyroid nodule by a surgeon.
- The thyroid nodule is looked at under a microscope by a pathologist who will then decide if the nodule is benign (95% to 99% of all nodules that are biopsied are benign) or malignant (less than 1% of all nodules, and about 1% to 5% of nodules that are biopsied).
- The pathologist decides the type of thyroid cancer: papillary, follicular, mixed papilofollicuar, medullary, or anaplastic.
- The entire thyroid is surgically removed; sometimes this is done during the same operation where the biopsy takes place. Your surgeon will assess the lymph nodes in the neck to see if they also need to be removed. In the case of anaplastic thyroid cancer, your doctor will help you decide about the possibility of a tracheostomy.
- About 4 to 6 weeks after the thyroid has been removed, you will undergo radioactive iodine treatment. This is very simple and consists of taking a single pill in a dose that has been calculated just for you. You will need avoid contact with other people for a couple of days so that others are not exposed to the radioactive materials.
- A week or 2 after the radioactive iodine treatment, you will have to start taking a thyroid hormone pill. No one can live without thyroid hormone, and if you don't have a thyroid anymore, you will need to take levothyroxine (usually one pill a day) for the rest of your life. This is a very common medication (examples of brand names include Synthroid and Levoxyl).
- Every 6 to 12 months, you will visit your endocrinologist for blood tests to determine if the dose of daily thyroid hormone is correct and to make sure that the thyroid tumor did not return. The frequency of these follow-up tests will vary greatly from patient to patient. Endocrinologists are typically quite good at this and will typically be the type of doctor that you follow up with long-term.
Thyroid Cancer Conclusion
If you're diagnosed with thyroid cancer, your doctor will create a thyroid cancer treatment plan for you—one that may incorporate a combination of thyroid cancer treatments, such as radioactive iodine and thyroidectomy.