Endocrine Abstracts

Objectives: In May 2016, the local thyroid cancer tumor group proposed and adopted specific thyroid lobectomy recommendations based on the 2015 ATA guidelines. ThyroSPEC molecular testing was introduced for all Bethesda III and IV lesions in August 2020. The goal of this study was to evaluate the implementation of the ATA lobectomy guidelines and the introduction of ThyroSPEC molecular testing on rates of upfront total thyroidectomy (TTx), diagnostic lobectomy for Bethesda I-IV (DxL), therapeutic lobectomy for Bethesda V-VI or high-risk/malignant molecular mutation (TxL), and completion thyroidectomy (CTx) by reviewing data from a tertiary thyroid cancer referral setting.

Methods: Data were collected from a prospective thyroid cancer database from April 2017 to October 2022. Patients with non-differentiated thyroid cancer, those who underwent subtotal thyroidectomy, no surgery, or who had undergone surgery at an outside center were excluded. Patients were classified as having TTx, DxL, TxL, or CTx.

Results: A total of 724 differentiated thyroid cancer patients were included in this study. There were 531 (73%) TTx and 193 (27%) lobectomies as the initial surgery, with 107 (55%) patients undergoing DxL, and 86 (45%) patients undergoing TxL. CTx was most often indicated due to postoperative findings of ATA intermediate or high recurrence risk thyroid cancer. 56/107 (52%) of the DxL patients underwent CTx, with 39/63 (62%) occurring pre-ThyroSPEC and 17/44 (39%) occurring post-ThyroSPEC (P < 0.05). Of the TxL, 26/86 (30%) underwent CTx, with a similar rate pre- and post-ThyroSPEC (29% and 32%, P = 0.788). Meanwhile, there was an increase in upfront TTx from 28% pre-ThyroSPEC to 47% post-ThyroSPEC (P < 0.05) for Bethesda III and IV nodules, with 12 patients with Bethesda III or IV undergoing upfront TTx due to malignant molecular markers or high-risk mutations in the post-ThyroSPEC group. There was also an increase in initial lobectomies (DxL and TxL) that did not require CTx from 14% to 22% (P < 0.05) pre- and post-ThyroSPEC.

Conclusions: The introduction of specific thyroid lobectomy recommendations and ThyroSPEC molecular testing resulted in an increase in upfront total thyroidectomies due to malignant molecular markers or high-risk mutations and a decrease in patients requiring completion thyroidectomy post lobectomy. This translates to more patients receiving an appropriate diagnostic or therapeutic surgery upfront and fewer second operations for completion thyroidectomy. This decreases the cost to the patient in terms of anxiety, time off work, and need for recurrent surgery, as well as cost to the health care system.