AACE Updates Thyroid Nodule Management Guideline

Marlene Busko

May 28, 2016

The American Association of Clinical Endocrinologists (AACE), the American College of Endocrinology (ACE), and the Associazione Medici Endocrinologi (AME) have quietly jointly released an important update to their "Medical Guidelines for Clinical Practice for the Diagnosis and Management of Thyroid Nodules," published online May 25 in Endocrine Practice.

The original AACE/ACE/AME thyroid-nodule management guideline was published in 2006 and first updated in 2010.

This new update incorporates recent scientific evidence and novel tools and treatments. It covers ultrasound-based classification of malignancy risk; indications for ultrasound-guided fine-needle-aspiration biopsy; classification of biopsy samples; immunocytochemistry and molecular testing; therapeutic options; and follow-up strategies.

It generally provides similar recommendations to those in the 2015 American Thyroid Association (ATA) Management Guidelines For Adult Patients With Thyroid Nodules And Differentiated Thyroid Cancer but goes into more detail, and there are a few minor differences, writing committee cochair and past president of the AACE and the ATA, Dr Hossein Gharib, from the Mayo Clinic College of Medicine, in Rochester, Minnesota, told Medscape Medical News.

Whereas with the ATA guideline "the emphasis clearly is on thyroid cancer — with some discussion (10% to 20%) on thyroid nodules," the AACE update focuses specifically on thyroid nodules and thus covers this topic in more depth — for example, it also covers nonsurgical treatments, Dr Gharib pointed out.

Dr Gharib said he was disappointed that the 2016 American Association of Clinical Endocrinologists (AACE) 2016 Annual Meeting he is currently attending did not include a session devoted to this document.

"We need to do a better job" of making sure that not only endocrinologists but also primary-care physicians, pediatricians, internists, and surgeons who deal with patients with thyroid nodules know that these evidence-based guidelines are available, he stressed.

Invited to comment, Dr Mark A Lupo, from the Thyroid & Endocrine Center of Florida, in Sarasota, who was not involved with the guidelines but gave a presentation at the AACE meeting about thyroid-nodule features seen on ultrasound, told Medscape Medical News that "when you drill down, [the two guidelines] are very similar."

One big difference is that the AACE guidelines use a three-tier malignancy-risk classification system for thyroid nodules seen by ultrasound and the ATA uses a five-tier system to determine which patients should have a fine-needle-aspiration biopsy. The former classification system may be easier for clinicians to use and the latter one may be more precise for research, Dr Lupo speculated.

AACE guideline update coauthor Dr Daniel S Duick, from the University of Arizona Phoenix and Tucson campuses, echoed these observations.

AACE's focus on thyroid nodules as opposed to nodules and cancer allows for a more in-depth review of certain topics, he told Medscape Medical News. However, "virtually all recommendations are similar or the same for both sets of guidelines," with the notable exception of the different number of risk categories used to determine the need to biopsy a thyroid nodule.

AACE vs ATA Thyroid-Nodule-Management Differences

Based on thyroid nodules' size and characteristics seen on ultrasound scans, AACE classifies them into three malignancy-risk categories: low, intermediate, and high. ATA goes further, classifying the risk categories as: benign, very low, low, intermediate, and high suspicion.

According to Dr Duick, this difference "most likely reflects decision making where, more commonly, the operator-based sonographer and performer of fine-needle aspiration is an endocrinologist/thyroidologist [in the AACE classification] rather than a radiology technologist, radiologist, or other," in the ATA classification.

The ATA guidelines recommend that nodules > 1 cm in diameter should be biopsied, but smaller nodules, even if they are suspicious for cancer, only should be followed closely, Dr Gharib said. In contrast, the AACE guideline is somewhat less restrictive and states, "Fine-needle aspiration should be considered for nodules < 10 mm (1 cm) diameter only when suspicious ultrasound signs are present, while nodules < 5 mm should be monitored rather than biopsied."

"Importantly, [both guidelines] highlight pattern recognition," Dr Lupo observed, adding that it is important "to have access to a video clip or do [the ultrasound] yourself, to be able to better distinguish a high-risk feature from an artifact."

And tests for molecular markers for thyroid cancer, a hotly debated area, are treated differently in the two guidelines, Dr Gharib noted. The ATA guidelines suggest that clinicians should order these tests if cytology findings are atypical, whereas the AACE guideline uses more cautious wording: "At present, no single cytochemical or genetic marker can definitely rule out malignancy in indeterminate nodules. Nevertheless, these tools should be considered together with clinical data."

There is no need to treat most thyroid nodules, and levothyroxine (LT4) suppression is not recommended, according to the AACE guideline update.

The document also discusses noninvasive treatment in more detail. "Percutaneous ethanol injection (PEI) should be the first-line treatment option for relapsing, benign cystic lesions, while [ultrasound]-guided thermal ablation treatments may be considered for solid or mixed symptomatic benign thyroid nodules," the AACE authors write.

"Minimally invasive procedures are much more commonly done in Europe than in the United States," Dr Gharib observed, adding that "we have to tell our colleagues" that alcohol ablation is easy to do and radiofrequency ablation is both effective and cost-effective.

Last, "surgery remains the treatment of choice for malignant or suspicious nodules," according to the AACE thyroid nodule management guideline update.

Need to Consider Individual Patient, Avoid Overtreatment

According to Dr Gharib, technologic advances are enabling clinicians to detect smaller nodules, which often leads to surgery, and "perhaps we are a little bit too aggressive with chasing small nodules."

In any case, "the individual patient situation may not conform to rigid guidelines," Dr Lupo noted. "You have to always use clinical judgment and tools that are available in your location."

Dr Gharib reports that he does not have any relevant financial relationships.

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Endocr Pract. 2016;22:622-639. Article


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