Applying Criteria of Active Surveillance to Low-Risk Papillary Thyroid Cancer over a Decade: How Many Surgeries and Complications Can Be Avoided?

Background: The 2015 American Thyroid Association guidelines acknowledged that "an active surveillance management approach can be considered as an alternative to immediate surgery" in patients with low-risk papillary thyroid carcinoma (PTC). The aim of this study was to determine the proportion of PTC that would meet the criteria for active surveillance and the surgeries and complications that could have been avoided. Methods: A total of 681 patients with thyroid cancer who underwent thyroid surgery from 2003 to 2012 were retrospectively reviewed. A decision-making framework for active surveillance was applied to patients with PTC in nodules measuring ≤1.5 cm on ultrasound. Patients were identified as suitable for active surveillance based on imaging and patient characteristics. These patients were reviewed for management and outcomes. Results: PTC was diagnosed based on fine-needle aspiration histology of Bethesda V or VI in thyroid nodules in 243 patients. Of these, 77 patients had nodules measuring ≤1.5 cm on ultrasound, and 56/77 (23%) patients met the criteria for surveillance: 15/243 (6%) patients met the criteria with a ≤1 cm size threshold, and 41/243 (17%) met the criteria with a 1.1-1.5 cm threshold. Of the 56 patients who met the criteria for active surveillance, 52 underwent total thyroidectomy, and four had a lobectomy. Forty-five (80%) patients had elective central nodal dissection, and 14 had nodal metastases on pathology (all <4 mm). Three patients had permanent complications from surgery, including vocal cord paralysis, hypoparathyroidism, and a chipped tooth from intubation. No patients died or had recurrent disease. Conclusion: Future programs in the United States should consider increasing the size threshold for active surveillance of PTC to 1.5 cm, since this will allow up to one quarter of patients to be eligible instead of only 6% with a 1 cm size threshold. Without an active surveillance program, the majority of patients with low-risk cancers have thyroidectomy and carry a small risk of permanent complications.