Less extensive surgery for low-risk papillary thyroid cancers post 2015 American Thyroid Association guidelines in an Australian tertiary centre.

Abstract

INTRODUCTION\nThe 2015 American Thyroid Association guidelines (ATA15) consider hemithyroidectomy (HT) a viable treatment option for low-risk papillary thyroid cancers (PTCs) between 1 and 4\xa0cm. We aimed to examine the impact of ATA15 in a high-volume Australian endocrine surgery unit.\n\n\nMETHODS\nA retrospective study of all patients undergoing thyroidectomy from January 2010 to December 2019.\n\n\nINCLUSION CRITERIA\nPTC histopathology, Bethesda V-VI, size 1-4\xa0cm, and absence of clinical evidence of lymph node or distant metastases pre-operatively. Primary outcome was rate of HT before and after ATA15.\n\n\nRESULTS\nOf 5408 thyroidectomy patients, 339 (6.3%) met the inclusion criteria - 186 (54.9%) pre-ATA15 (2010-2015) and 153 (45.1%) post-ATA15 (2016-2019). The patient groups were similar; there were no significant differences between groups in age, sex, tumour size, proportion with Bethesda VI cytology, compressive symptoms, or thyrotoxicosis. Post-ATA15, there was a significant increase in HT rate from 5.4% to 19.6% (P\xa0=\xa00.0001). However, there was no corresponding increase in completion thyroidectomy (CT) rate (50.0% versus 27.6%, P\xa0=\xa00.2). The proportion managed with prophylactic central neck dissection (pCND) fell from 80.5% to 10.8% (P\xa0<\xa00.0001). Pre-ATA15, the only factor significantly associated with HT was Bethesda V. In contrast, post-ATA15, HT was more likely in patients with younger age, smaller tumours, and Bethesda V.\n\n\nCONCLUSION\nAfter the release of 2015 ATA guidelines, we observed a significant increase in HT rate and a significant decrease in pCND rate for low-risk PTCs in our specialised thyroid cancer unit. This reflects a growing clinician uptake of a more conservative approach as recommended by ATA15.