Conditions: Papillary Thyroid Carcinoma

Thyroid nodule versus thyroid cancer

A thyroid nodule is a general term for a growth or lump that forms within the thyroid gland. As about 5% of all nodules are cancerous, almost all thyroid nodules prove not to be cancerous after evaluation.

WHAT IS Papillary thyroid carcinoma?

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer. The thyroid is a small, butterfly-shaped gland at the front of your neck that makes hormones to help control your metabolism, heart rate, and body temperature. PTC starts in the cells that make these hormones. It accounts for about 85–90% of all thyroid cancers.

How common is it?

About 44,000 new cases of thyroid cancer are diagnosed each year in the United States, and the vast majority are papillary thyroid carcinoma. It is about 3 times more common in women than in men, and the average age at diagnosis is in the early 50s.

What causes it?

In most cases, there is no single clear cause. Known risk factors include:

• Exposure to radiation in childhood (the strongest known risk factor)

• Family history of thyroid cancer

• Being female

• Certain inherited genetic conditions (such as familial adenomatous polyposis or Cowden syndrome)

Most people diagnosed with PTC have none of these risk factors.

What are the symptoms?

Most people with PTC have no symptoms at all. The cancer is often found during a routine physical exam or on an imaging test done for another reason. When symptoms do occur, they may include:

• A painless lump or nodule in the neck

• Swollen lymph nodes in the neck

• Difficulty swallowing or a feeling of something in the throat

• Hoarseness or voice changes (less common, usually with more advanced disease)

How is it diagnosed?

• Ultrasound of the thyroid and neck is the main imaging test used.

• Fine-needle aspiration (FNA) biopsy — a thin needle is used to take a small sample of cells from the thyroid nodule. This is the best test to determine if a nodule is cancerous.

• Additional imaging (such as CT or MRI) may be done if needed.

How is it treated?

Treatment depends on the size of the tumor and whether it has spread:

• Very small cancers (1 cm or less): In some cases, your doctor may recommend close monitoring with regular ultrasounds instead of immediate surgery. This is called "active surveillance."

• Thyroid Surgery: Most PTC is treated with surgery. This may involve removing part of the thyroid (lobectomy) or the entire thyroid (total thyroidectomy). If cancer has spread to nearby lymph nodes, those may be removed as well.

• Radioactive iodine (RAI): After surgery, some patients receive radioactive iodine ablation treatment to destroy any remaining thyroid tissue or cancer cells. This is more commonly used for larger tumors or those with a higher risk of coming back.

• Thyroid hormone therapy: After thyroid surgery, you will need to take a daily thyroid hormone pill (levothyroxine) for the rest of your life. This replaces the hormones your thyroid used to make and can also help prevent the cancer from returning.

• Other treatments: In rare cases where the cancer is advanced or does not respond to radioactive iodine, targeted drug therapies may be used.

What is the outlook?

The outlook for papillary thyroid carcinoma is very good. The overall 5-year survival rate is greater than 98%. For cancers that have not spread beyond the neck (which is about 95% of cases at diagnosis), the survival rate is even higher. Even when the cancer has spread to distant parts of the body, many patients — especially younger ones — still do well with treatment.

It is important to keep up with follow-up appointments after treatment. Your doctor will monitor you with blood tests and ultrasounds to check for any signs of the cancer returning.