Some Growths Do No Harm

Benign thyroid nodules often did not lead to cancer or illness

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) Panic may be the first response for some patients who discover they have a growth. Many growths in the thyroid gland, however, don't go on to cause harm.

A new study of patients with symptomless growths in the thyroid gland found that, after several years, few became cancerous — regardless of whether they grew in size.

"Thyroid nodule diagnosis has become an increasingly frequent event in clinical practice," wrote the authors of this study, led by Sebastiano Filetti, MD, of the Università di Roma Sapienza, in Italy.

Thyroid nodules are growths or swelling in the thyroid gland. The thyroid is located in the neck. It is a part of the endocrine system, responsible for producing hormones.

In most cases of thyroid nodules, there are no symptoms tied to the swelling. However, in some cases, the nodules could develop into thyroid cancer.

Though better diagnostic tools have helped doctors discover more of these growths, there is disagreement about how to best follow up, Dr. Filetti and team wrote.

Current guidelines suggest repeat exams of the nodules, focusing on growth in size as a red flag. Dr. Filetti and team wanted to study how these nodules may affect patient health over time.

To do so, they looked at nearly 1,000 patients at eight health centers in Italy between 2006 and 2008.

These patients all had between one and four thyroid nodules and were followed until January 2013. None reported any symptoms tied to the growths.

During the follow-up, 153 patients (15.4 percent) had significant growth of thyroid nodules. Shrinking of the thyroid nodules was slightly more common and seen in 184 patients (18.5 percent).

Patients who experienced growth were more likely to have more than one nodule and be male.

Only five of the original 1,567 nodules (0.3 percent) developed thyroid cancer during the follow-up. Of these five, only two had grown in size.

Also, 93 new nodules were discovered during the follow-up — one of which was diagnosed with cancer.

In an editorial about this study, Anne R. Cappola, MD, ScM, of the Perelman School of Medicine at the University of Pennsylvania in Philadelphia, suggested that a detailed initial examination is key to identifying potentially harmful thyroid nodules.

Dr. Cappola pointed out that most of the nodules that did become cancerous in this study had suspicious features, including odd shape and other irregularities, upon examination.

Reducing the number of exams for thyroid nodules that don't appear suspicious might be the best route, Dr. Cappola suggested, especially because the risk of developing thyroid cancer seemed low.

"Thyroid nodules are pervasive, whereas thyroid cancer is not," Dr. Cappola wrote.

Patients who are concerned about any type of growth should see a doctor.

Dr. Filetti and team noted a need for further research on a more diverse population to explore these findings.

The study and editorial were published March 3 in JAMA.

A number of groups funded this research, such as the Italian Thyroid Cancer Observatory Foundation. The authors disclosed no conflicts of interest.

Review Date: 
March 2, 2015
Last Updated:
March 4, 2015