Definition: Papillary carcinoma of the thyroid is the most common cancer of the thyroid gland. The thyroid gland is located inside the front of the lower neck.
Papillary carcinoma is more common in women than in men. It may occur in childhood, but is most often seen in adults between ages 20 and 60.
The cause of this cancer is unknown. A genetic defect or family history of the disease may also be a risk factor.
Radiation increases the risk of developing thyroid cancer. Exposure may occur from:
- High-dose external radiation treatments to the neck, especially during childhood, used to treat childhood cancer or some noncancerous childhood conditions
- Radiation exposure from nuclear plant disasters
Radiation given through a vein (through an IV) during medical tests and treatments does not increase the risk of developing thyroid cancer.
Thyroid cancer often begins as a small lump (nodule) in the thyroid gland.
While some small lumps may be cancer, most (90%) thyroid nodules are harmless and are not cancerous.
Most of the time, there are no other symptoms.
If you have a lump on your thyroid, your health care provider will order blood tests and possibly an ultrasound of the thyroid gland.
If the ultrasound shows that the lump is less than 1 centimeter, a special procedure called a fine needle aspiration biopsy (FNAB) may be performed. This test helps determine if the lump is cancerous.
CT scan of the neck may also be done to determine the size of the tumour.
Thyroid function tests are often normal in people with thyroid cancer.
There are three types of thyroid cancer treatment:
- Radioactive iodine
Surgery is done to remove as much of the cancer as possible. The bigger the lump, the more of the thyroid gland must be removed. Often, the entire gland is taken out.
After the surgery, you may receive radioiodine therapy, which is often taken by mouth. This substance kills any remaining thyroid tissue. It also helps make medical images clearer, so doctors can see if there is any cancer left behind or if it comes back later.
If surgery is not an option, external radiation therapy can be useful.
After surgery or radioiodine therapy, you will need to take medicine called levothyroxine for the rest of your life. This replaces the hormone the thyroid would normally make.
Your provider will likely have you take a blood test every several months to check thyroid hormone levels. Other follow-up tests that may be done after treatment for thyroid cancer include:
- Ultrasound of the thyroid
- An imaging test called a radioactive iodine (I-131) uptake scan
- Repeat FNAB
You can ease the stress of illness by joining a cancer support group. Sharing with others who have common experiences and problems can help you not feel alone.
The survival rate for papillary thyroid cancer is excellent. More than 90% of adults with this cancer survive at least 10 to 20 years. The prognosis is better for people who are younger than 40 and for those with smaller tumors.
The following factors may decrease the survival rate:
- Older than 55
- Cancer that has spread to distant parts of the body
- Cancer that has spread to soft tissue
- Large tumour
- Accidental removal of the parathyroid gland, which helps regulate blood calcium levels
- Damage to a nerve that controls the vocal cords
- Spreading of cancer to lymph nodes (rare)
- Spreading of cancer to other sites (metastasis)
Call your provider if you have a lump in your neck.
National Cancer Institute website. Thyroid cancer treatment (adult) (PDQ) – health provisional version. www.cancer.gov/cancertopics/pdq/treatment/thyroid/HealthProfessional. Updated February 1, 2018. Accessed March 22, 2018.
Thompson LDR. Malignant neoplasms of the thyroid gland. In: Thompson LDR, Bishop JA, eds. Head and Neck Pathology. 3rd ed. Philadelphia, PA: Elsevier; 2019:chap 25.