Why Thyroid Cancer Is on the Rise

Early Detection Through Ultrasound Plays a Key Role

Technician examining chart
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You or a loved one may have been diagnosed with thyroid cancer after finding a lump or swelling in your neck. Alternatively, your doctor may have found a lump during a routine physical examination or incidentally during an ultrasound of a structure near your thyroid (like your carotid arteries). 

Thyroid Cancer on the Rise

According to the American Cancer Society, approximately 54 thousand people will develop thyroid cancer in the United States in the next year, and this number has risen in recent years.

In fact, thyroid cancer is the most rapidly increasing cancer in the United States

The "why" behind the rise of thyroid cancer is likely two-fold, according to a study in JAMA. The primary reason for the rise in thyroid cancer can be explained by the increased use of thyroid ultrasound, which can detect smaller thyroid nodules that may not have been detected in the past.

In other words, overdiagnosis is a problem, as imaging techniques (like ultrasound) and fine-needle aspiration biopsies have detected small thyroid tumors (< 2cm) that were indolent or not worrisome at the time (causing no immediate symptoms or need for treatment). 

The other reason, albeit small according to the JAMA study, is a possible change in exposure to risk factors like obesity and noncurrent smoking. Environmental exposure to chemicals like pesticides and bisphenol A may also play a role, although the scientific evidence linking exposure to these chemicals with thyroid cancer risk is scant.

Prognosis of Thyroid Cancer

It's important to note that while cases of thyroid cancer have risen in recent years, the death rate for thyroid cancer has remained fairly steady. In fact, the death rate (approximately two thousand deaths a year from thyroid cancer) is quite low, as compared to other types of cancer.

The bottom line is that the prognosis of the most common thyroid cancers (papillary and follicular thyroid cancer) is very good.

Let's take a closer look at the survival statistics for papillary thyroid cancer, which is the most common types of thyroid cancer, occurring in approximately 80 percent of all cases.

Survival Statistics of Papillary Thyroid Cancer

The 5-year survival rate (your chance of being alive at least 5 years after being diagnosed) is nearly 100 percent for people diagnosed with papillary thyroid cancer that is limited to the thyroid gland. 

Of course, as a papillary thyroid cancer spreads to the lymph nodes, surrounding muscles and tissues, or even distant organs, the survival rates decline. In fact, according to the study in JAMA, there is an increased rate of dying from advanced papillary thyroid cancer in the last five decades. 

Keep in mind these numbers are statistics; they do not predict any one person's chance of surviving. 

Remember, the 5-year survival rate only looks at 5 years after diagnosis. There is a very good chance a person diagnosed with thyroid cancer lives for more than 5 years. In fact, death from stage I papillary thyroid cancer is extremely rare.

A Word from Verywell

While alarming and frightening to see the increased incidence of thyroid cancer, it's important to understand that much of this can be attributed to increased use of diagnostic strategies. Your chance of recovery from thyroid cancer is excellent, so remain proactive in your health and ask a lot of questions as your cancer care is being worked out.

Sources:

American Cancer Society. (2018). Key Statistics for Thyroid Cancer. 

American Thyroid Association. (n.d.). Thyroid Cancer (Papillary and Follicular). 

Lim H, Devesa SS, Sosa JA, Check D, Kitahara CM. Trends in thyroid cancer incidence and mortality in the United States, 1974-2013. JAMA 2017 Apr 4;317(13):1338-48.