September is Thyroid Cancer Awareness Month. While thyroid cancer is less common than lung, breast, colorectal and prostate cancer, the number of people diagnosed with the disease is increasing.
Studies indicate that since the 1970s, the number of thyroid cancer cases has more than doubled. The American Thyroid Association says the number of newly diagnosed cases of the disease is increasing at a rate faster than other types of cancer. In 2009, the American Cancer Society (ACS) estimated there were 37,200 new cases of thyroid cancer in the United States. It estimates there will be 60,220 cases in 2013.
“Most believe the rise in incidence is related to early detection by radiological studies,” notes Dr. Michael Rotkowitz, a medical oncologist at CTCA in Philadelphia. Ultrasound tests and fine-needle aspiration biopsies have helped doctors diagnose cases that previously may have gone undetected.
Sometimes thyroid cancer is accidentally found when patients undergo ultrasound tests for enlarged or overactive parathyroid glands or a narrowing of the carotid arteries in the neck, which supply blood to the brain. More often, though, the disease is discovered when people see their primary care physician for a physical exam because they notice a nodule or lump in their neck.
If a patient’s physician finds a lump or nodule, the patient undergoes a series of tests, including an ultrasound of the thyroid to see if there's a mass in the gland. The patient may also have a radioiodine scan, a type of nuclear medicine test which involves swallowing or injecting a small amount of radioactive iodine. If the scan shows the nodule has less radioactivity than the tissue surrounding it, the nodule could be cancerous. A biopsy is then taken of the suspicious tissue or cells to make the actual diagnosis.
While detection of small thyroid nodules has improved, the majority of nodules are benign. On average, one in 20 is cancerous.
Another eye-opening fact about thyroid cancer is that women are three times as likely as men to develop the disease. Why it is more predominant among women has yet to be determined. ACS reports women are typically in their 40s or 50s when they are diagnosed, while most men are in their 60s or 70s.
Learn more about thyroid cancer risk factors and diagnosis.