CORONADO, CALIF. – Expect significant enhancements to the updated thyroid cancer management guidelines from the American Thyroid Association, due to be released in early 2015.
Last updated in 2009, the goal of the new guidelines is to “be evidence based and helpful,” guidelines task force chair Dr. Bryan R. Haugen said at the annual meeting of the American Thyroid Association. For example, the new guidelines will contain 101 recommendations, up from 80 in the 2009 version; 175 subrecommendations, up from 103; and 998 references, up from 437. “Still, 59 of the existing 80 recommendations are not substantially changed, showing a general stability in our field over the past 5 to 6 years,” he said.
One enhancement is a definition of risk of structural disease recurrence in patients without structurally identifiable disease after initial therapy for thyroid cancer. Low risk is defined as intrathyroidal differentiated thyroid cancer involving up to five metastases less than 0.2 cm in size. Intermediate risk is defined as the presence of aggressive histology, minor extrathyroidal extension, vascular invasion, or more than five involved lymph nodes with metastases 0.2-0.3 cm in size. High risk is defined as the presence of gross extrathyroidal extension, incomplete tumor resection, distant metastases, or lymph node metastases greater than 3 cm in size.
The guidelines also include a table that defines a patient’s response to therapy as a dynamic risk assessment. “This best applies to the low- to intermediate-risk patients, although it definitely applies to high risk as well,” said Dr. Haugen, who heads the division of endocrinology, metabolism, and diabetes at the University of Colorado Health Sciences Center, Denver. “It’s [a] strong recommendation based on low-quality evidence to use this risk-based response to therapy. A lot of this data is generated from patients who’ve had a thyroidectomy and have received radioiodine. So we’re on a bit more shaky ground right now in a patient who’s had a thyroidectomy but no radioiodine, or a patient who’s had a lobectomy.”
Other changes include the concept that it’s not necessary to biopsy every nodule more than 1 cm in size. “We’re going to be guided by the sonographic pattern in who we biopsy and how we monitor them,” Dr. Haugen explained. “A new recommendation adds follow-up guidance for nodules that do not meet FNA [fine-needle aspiration] criteria. We’re also recommending use of the Bethesda Cytology Classification System for cytology.”
Changes in the initial management of thyroid cancer include a recommendation for cross-sectional imaging with contrast for higher-risk disease and the consideration of lobectomy for some patients with tumors 1-4 cm in size. “This is a controversial recommendation,” Dr. Haugen said. “We got some feedback from members asking if you do it, what’s the TSH target? Should we give them synthetic levothyroxine? We are revising the guidelines based on this feedback to help guide clinicians.”
The new guidelines also call for more detailed/standardized pathology reports, with inclusion of lymph node size, extranodal invasion, and the number of invaded vessels. “I’ve talked to a number of pathologists and clinicians who are very happy about this guidance,” he said. “We also need to look at tumor stage, recurrence risk, and response to therapy in our patients, and the use of selective radioiodine. There is some more information on considering lower administered activities, especially in the lower-risk patients.”
For the first time, the guidelines include a section on radioiodine treatment for refractory differentiated thyroid cancer, including tips on directed therapy, clinical trials, systemic therapy, and bone-specific therapy.
Dr. Haugen disclosed that he has received grants and research support from Veracyte and Genzyme.
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