The Increase in Thyroid Cancer

While the incidence of many cancers is declining, thyroid cancer is one that is steadily soaring, especially in women. It’s got everyone wondering why this hormonal powerhouse is taking such a hit.

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There is a worrisome trend emerging that puts the lives of women at great risk, and you might be staring at it each time you look in the mirror. The number of cases of thyroid cancer has more then doubled since the 1970s and that has a lot of people wondering why. Thyroid cancer is one of those stealth cancers that can grow under the radar, sometimes for decades. For this reason, catching it early is critical.

It's a wonder that this tiny gland with so much responsibility would fail to announce it is harboring a potential deadly cancer. The thyroid gland is the body's engine driver; it manufactures the thyroid hormone that is used to fuel metabolism and oversees the activities of other critical hormones produced elsewhere. When the amount of thyroid hormone is unbalanced – too much hormone causes hyperthyroidism, too little, hypothyroidism – it can wreak havoc in the body.

The thyroid gland is located just under the skin, splayed like a butterfly across the windpipe, right below the Adam's apple. About 5% of women and 1% of men with adequate dietary iodine (an essential element for thyroid health) have small bumps of tissue in and about the gland called thyroid nodules. For the most part, thyroid nodules never cause any trouble; they are just benign irregularities. In fact, most people will develop a thyroid nodule by the time they are 60 years old.

Some nodules however, can be cancerous although they are not generally life threatening. A few studies have shown that cancerous nodules are a common finding when autopsies are performed on people who died from other causes. This suggests that thyroid cancer may be present in many more people, but it never becomes lethal. But not all cancerous nodules have that laid-back temperament.

And that is why this increase in diagnosis is troubling.

Why is Thyroid Cancer on the Rise?
It's not clear what is causing this upward trend in thyroid cancer diagnoses. Some think the increase is attributed to improved and more precise diagnostic technology, like imaging and biopsy techniques, because the increase incidence was primarily from hard to detect, tiny tumors. Still, there are some reasons to believe that other factors may be involved.

When the number of people diagnosed with a condition climbs inexplicably, doctors look for clues to help explain it. Thyroid cancer is 4 times more common in women then men, so the finger naturally points to estrogen. And it has been suggested in some studies that estrogen might fuel the growth of thyroid cancer cells, which have surface receptors with a particular affinity for estrogen. (Estrogen also fuels some types of breast cancers.)

Interestingly, the increase in thyroid cancer also began to rise just as X-ray radiation was being routinely used to diagnose and treat disease. This was a time when X-rays were not only stronger, but also used indiscriminately for some unworthy conditions such as acne and tonsillitis. It was even used to measure foot size in the local shoe store.

The thyroid gland however, is very sensitive to radiation; it is a leading risk factor for the condition, especially if exposure occurred during childhood. Additionally, the thyroid can be inadvertently exposed during high-dose radiation therapy targeted to treat other types of cancer, particularly if the radioactive beam enters an area close to the gland such as the chest, neck and head, or from total body radiation used prior to bone marrow transplantation.

And although routine dental X-rays, chest X-rays and mammograms of today use much lower and safer amounts of radiation, some worry about this as a thyroid-damaging source. Some professionals say to protect the thyroid people should wear a lead thyroid shield (and apron when possible) when undergoing these procedures block radiation reaching the thyroid gland, and to limit tests using X-rays to those that are absolutely necessary.

Other risk factors for thyroid cancer include hereditary conditions and iodine deficiency (rare in the US because of iodized salts).

Identifying Nodules
Thyroid nodules don't usually produce symptoms when they are tiny, but larger ones might be notable. Since the thyroid sits close to the skin's surface larger lumps can be detected with the touch of the hand or naked eye. Nodules are mostly a benign fluid-filled cyst, pool of thyroid hormone, or harmless gathering of cells. This type of nodule (or a goiter, a condition that causes whole gland to enlarge), it is not likely to be cancer.

Only 1 in 20 nodules are cancerous.

Spotting Thyroid Cancer
If your doctor still performs a physical exam, one area he or she will exam is the neck. You can ask for this simple exam specifically. Nodules can also be found by accident, during imaging study performed for another reason.

Although thyroid cancer doesn’t usually produce symptoms, larger masses can cause the following:

  • Difficulty swallowing
  • Sore throat or a pain in the neck
  • Voice changes or hoarseness
  • Persistent cough
  • Trouble breathing

The risk of a nodule being cancerous is that same no matter how the nodule is found. Thankfully, most cancers are detected at an early curable stage; and 90% are disease free after treatment.

The Thyroid Self-Exam
One easy way to get a hold on thyroid health is to get to know your thyroid better by performing periodic thyroid self-exams. Like a breast self-exam, doing this evaluation routinely lets you become more familiar with the terrain. If you find a lump, even if it is the size of a tiny pebble, have it checked by a doctor.

Here's how to do it:

  • Stand in front of a mirror keeping your eye on the area just below the Adam's apple and right above the collarbone.
  • Drink some water and tilt your head back slightly, just enough to keep your eye focused on the thyroid area while you swallow
  • Look and feel for any bulges and bumps
  • Repeat a few times
  • Report any findings to your doctor

Watch Dr. Oz demonstrate the proper way to perform a thyroid self-exam.

Tests for Thyroid Cancer
Some nodules are more worrisome than others and that will depend on the size and characteristics of the tumor. It is difficult to tell by look and feel if a nodule is cancer. Doctors decide on a course of action based on the results of imaging and blood tests. For instance, if hormones are out-of-whack, it probably isn't cancer.

Tests performed to diagnose thyroid cancer

  • Blood tests measuring thyroid stimulating hormone (TSH) to assess thyroid functioning (hypothyroidism or hyperthyroidism)
  • Diagnostic thyroid ultrasound to measure and determine features of the nodule(s)
  • Radionuclide thyroid scan to assess activity inside the nodules
  • Fine-needle aspiration biopsy (FNAB) to view a sample of the nodule's tissue under the microscope

The most common type of thyroid cancer is the papillary type (87% of the increased trend in incidence was this type), which is also the most responsive to treatment and cure.

Treatment for Thyroid Cancer
Treatment for thyroid cancer will involve surgery (near-total or total thyroid removal or thyroidectomy) alone, or combined with radiation, radioactive seeds, chemotherapy, hormone therapy or targeted therapy, a type of treatment that takes specific aim at thyroid cancer cells.

People who have their thyroid removed are given thyroid hormone replacement therapy permanently, to take over for the removed thyroid gland.