By: Prof. Dr. Seyed Saeid Zamanieh Shahri, MD  and  Prof. Dr. Sonia Sayyedalhosseini, MD

Cervical cancer:

Thyroid cancer:

Thyroid cancer is a rare type of cancer that affects the thyroid gland. The thyroid is a small gland in the lower neck that produces certain hormones. It is most common in people in their 40s and older. Women are two to three times more likely to develop the disease than men. Thyroid cancer is usually curable, especially if it is caught early; although sometimes the disease can come back after treatment.

What is thyroid cancer?

The thyroid is a small, butterfly-shaped gland located in the neck, below the Adam’s apple. The thyroid gland produces the hormones thyroxine (also called T4) and tri-iodothyronine (also known as T3). These hormones are involved in a number of body functions, such as temperature, mood, irritability, pulse rate, digestion, and more.

If thyroid tissue starts to grow uncontrollably, it can cause one or more lumps in the thyroid. It is not known why this happens! Cancerous masses can invade tissues in the neck or spread to other parts of the body through the lymph nodes and bloodstream.

Thyroid cancer staging:

The TNM system is usually used to stage thyroid cancer. This is a combination of letters and numbers that describe the size and extent of the cancer.

T (tumor): One to four describes the size of the tumor.

N (nodes): Zero to one indicates whether the cancer has spread to nearby lymph nodes.

M (metastasis): Zero to one indicates whether the cancer has spread to other parts of the body.

Knowing the stage of the cancer helps doctors prescribe the best treatment for the patient.

Types of Thyroid Cancer:

Papillary: This is the most common type of thyroid cancer and accounts for more than 70 percent of cancers in this area of the body. Papillary usually does not grow very quickly and spreads slowly through the body.

Follicular: This type of cancer accounts for 10 to 15 percent of thyroid cancers. Follicular cancer can spread through the bloodstream to other areas of the body, such as the lungs or bones.

Medullary: This type of cancer accounts for 4 percent of thyroid cancers. If there is a family history (a person in the family has had this cancer), other family members are also likely to develop this disease.

Anaplastic: This type of cancer is very rare and accounts for about 2 percent of thyroid cancers. Anaplastic cancer spreads quickly to other tissues in the body. Treatment for this type of cancer is difficult and is the least effective.

Causes of Thyroid Cancer:

Thyroid cancer occurs when a change occurs in the DNA of thyroid cells that causes them to grow uncontrollably and form a lump. It is usually not known exactly what causes this change, but there are many things that can increase the risk of developing this cancer. These include:

Thyroid diseases, such as an inflamed thyroid (thyroiditis) or a goiter. A family history of thyroid cancer increases the risk of developing thyroid cancer.

Exposure to radiation therapy during childhood increases the risk. Obesity can also cause thyroid cancer to some extent. Familial adenomatous polyposis (FAP) and acromegaly (a rare condition in which the body produces more growth hormone than normal) can also increase the risk of developing thyroid cancer.

Thyroid cancer risk factors:

Gender: Women are about three times more likely to get thyroid cancer than men.

Age: In women, thyroid cancer is usually diagnosed in their 40s and 50s. But in men, the disease usually appears in their 60s and 70s.

Family history (genetics): Thyroid cancer sometimes runs in families. Inheriting an abnormal gene can increase the risk of developing medullary cancer.

Radiation exposure: Exposure to nuclear radiation can increase the risk of developing cancer.

Tests such as X-rays and mammograms do not detect thyroid cancer.

Iodine deficiency: Iodine is needed to produce thyroid hormone. Thyroid cancer is more common in areas of the world where there is a lack of iodine in the diet, such as Central Asia and Central Africa.

Symptoms of Thyroid Cancer:

The main sign of thyroid cancer is a lump in the front of the neck. It grows slowly and may not cause any symptoms at first. Thyroid cancer often starts as a painless lump or a small swelling in the front of the neck. However, neck lumps are common and are usually caused by more serious conditions, such as an enlarged thyroid (goiter). Only about 1 in 20 neck lumps are linked to cancer.

A lump in the neck is more likely to be cancer if it:

Feels like a hard lump, The lump does not move easily under the skin (is fixed in place).

It gets bigger over time.

Other symptoms of thyroid cancer include: hoarseness, unexplained voice changes that don’t improve after a few weeks, chronic sore throat that doesn’t get better, neck pain, difficulty swallowing, and difficulty breathing. These symptoms can be caused by conditions other than cancer, but it’s important to see your doctor if you have any worrisome symptoms.

Note: Thyroid cancer rarely affects the production of thyroid hormones.

Thyroid Cancer Diagnosis:

See your doctor if you have any of the possible symptoms of thyroid cancer. The doctor will examine your neck and ask about your symptoms. It’s possible to have a thyroid problem but not cancer, so some important tests may be ordered to help make a diagnosis. Some of these tests include:

Blood Test: A blood test is used to test thyroid function and to check the amount of thyroid hormones in the blood. Abnormal levels of these hormones can mean that the patient has an overactive thyroid or an underactive thyroid. If the test shows that the thyroid hormone levels are normal but there are worrying symptoms, further tests, such as an ultrasound scan, will be needed.

Ultrasound Scan: An ultrasound scan uses sound waves to create a picture of the inside of the body. An ultrasound scan of the patient’s neck can examine the thyroid lump and show how dangerous it is. If a potentially cancerous tumor is found, a biopsy is done to confirm the diagnosis.

Biopsy: This is where a small sample of cells is removed and studied under a microscope. A thyroid biopsy is usually done by inserting a thin needle into the tumor. An ultrasound scan may be done at the same time to guide the needle to the right place.

The following tests also help diagnose thyroid cancer:

CT scan, PET scan, and MRI: These tests use different methods to determine the location of the thyroid cancer, its size, and how far it has spread.

Surgical biopsy: Since individual cancerous glands cannot be removed by biopsy, surgery is done to remove a portion of the thyroid.

Genetic testing: A genetic test is a blood test that looks at a patient’s DNA, or genetic information.

to be continued…