Thyroid Cancer: The Basics
Thyroid cancer is caused by thyroid cells growing out of control. As the number of cells grow, they form into a tumor. There are four major types of thyroid cancer:
- Papillary Carcinoma
- Follicular Carcinoma
- Medullary Carcinoma
Thyroid cancer that has spread from the thyroid to another part of the body, or from another part of the body to the thyroid, is called metastatic cancer.
Most cases are not the result of having a risk factor. Thyroid cancer affects more women than men. Some known risk factors include:
- Lack of dietary iodine
- Exposure to ionizing radiation to the neck area at a young age
- Family history
- Genetic mutations
Screening includes visual and physical examination of the neck during a routine physical exam. Some thyroid cancers are also found on tests such as ultrasound and CT scans of other organs.
Signs & Symptoms of Thyroid Cancer
The most common sign of thyroid cancer is a nodule (bump) found during a physical exam or found on a non-related scan. Larger thyroid nodules can cause:
- Hoarse voice
- Tracheal or esophageal compression
- Shortness of breath/air hunger
- Difficult or painful swallowing
- Neck Pain
Diagnosis of Thyroid Cancer
If your provider finds a thyroid nodule it is important to determine if the nodule is cancerous (malignant) or not (benign). A more thorough physical exam will be done and your provider will check to see if your lymph nodes are larger than usual. You may also have the following tests done:
- Blood tests to check how your thyroid is functioning.
- Ultrasound which can provide information about a nodule.
- If on an ultrasound the nodule appears to be cancer, then a fine needle aspiration (FNA) is done. During an FNA, a thin needle is placed into the nodule using ultrasound to guide it. Cells are removed to be examined in a laboratory. A pathology report summarizes these results and is sent to your healthcare provider. This report is an important part of planning your treatment. You can request a copy of your report for your records.
Staging Thyroid Cancer
To guide treatment, thyroid cancer is "staged." The four components used to describe the stage of thyroid cancer are:
- Size and location of the tumor
- Whether cancer cells are found in the lymph nodes
- Whether cancer cells are found in other areas of the body
- Tumor left after surgical treatment
This information is combined to give a stage from 0-IV, with IV being the most advanced.
Thyroid cancer treatment is dependent upon the type of thyroid cancer and can involve a number of different treatments.
- Surgery including total thyroidectomy (removal of whole thyroid), near total thyroidectomy (leaving small portion of thyroid gland and parathyroid glands), and lobectomy (removal of single lobe of thyroid gland). Lymph nodes are removed during surgery if the cancer has spread to them.
- Supplemental Thyroid Hormone Therapy is used after surgery in patients who had near total or total thyroidectomy to replace hormones no longer being made by the missing thyroid and can keep any left over thyroid cancer from recurring.
- Radioactive Iodine Therapy can be used to kill remaining thyroid tissue and cancer cells. The radioactive iodine is taken up by the thyroid cells, delivering a lethal dose of radiation to these cells.
- Radiation Therapy is used in aggressive types of thyroid cancer and for people at high risk of recurrence.
- Chemotherapy is used in the treatment of metastatic thyroid cancer.
This article is an introduction to thyroid cancer. You can learn more about thyroid cancer diagnosis and treatment by using the links below.