Lobectomy and completion thyroidectomy rates increase after the 2015 American Thyroid Association Differentiated Thyroid Cancer Guidelines update

Background The 2015 American Thyroid Association (ATA) Guidelines permit thyroid lobectomy (TL) or total thyroidectomy in the management of low-risk papillary thyroid cancer (PTC). As definitive risk-stratification is only possible post-operatively, some patients may require completion thyroidectomy (CT) after final histopathological analysis. Methods A retrospective cohort study of patients undergoing surgery for low-risk PTC in a tertiary referral centre was undertaken. Consecutive adult patients treated from January 2013 to March 2021 were divided into two groups (pre- and post-publication of ATA Guidelines on 01/01/2016). Only those eligible for lobectomy under rule 35(B) of the ATA Guidelines were included: Bethesda V/VI cytology, 1–4 cm post-operative size and without pre-operative evidence of extrathyroidal extension or nodal metastases. We examined rates of TL, CT, local recurrence and surgical complications. Results There were 1488 primary surgical procedures performed for PTC on consecutive adult patients during the study period, of which 461 were eligible for TL. Mean tumour size ( P = 0.20) and mean age ( P = 0.78) were similar between time periods. The TL rate increased significantly from 4.5 to 18% in the post-publication period ( P < 0.001). The proportion of TL patients requiring CT (43 vs 38%) was similar between groups ( P = 1.0). There was no significant change in complications ( P = 0.55) or local recurrence rates ( P = 0.24). Conclusion The introduction of the 2015 ATA Guidelines resulted in a modest but significant increase in the rate of lobectomy for eligible PTC patients. In the post-publication period, 38% of patients who underwent TL ultimately required CT after complete pathological analysis.