Extent of Surgery for Papillary Thyroid Cancer Is Not Associated with Survival: An Analysis of 61,775 Patients

Abstract

Structured Abstract Objective—To examine the association between extent of surgery and overall survival (OS) in a large contemporary cohort of patients with papillary thyroid cancer (PTC). Background—Guidelines recommend total thyroidectomy for PTC tumors >1 cm based on older data demonstrating an OS advantage for total thyroidectomy over lobectomy. Methods—Adult patients with PTC tumors 1.0–4.0 cm undergoing thyroidectomy in the National Cancer Database, 1998–2006, were included. Cox proportional hazards models were applied to measure the association between extent of surgery and OS while adjusting for patient demographic and clinical factors, including comorbidities, extrathyroidal extension, multifocality, nodal and distant metastases, and radioiodine treatment. Results—Among 61,775 PTC patients, 54,926 underwent total thyroidectomy and 6,849 lobectomy. Compared to lobectomy, total thyroidectomy patients had more nodal (7% vs. 27%), extrathyroidal (5% vs.16%), and multifocal disease (29% vs. 44%), all p<0.001. Median follow-up was 82 months (60–179 months). After multivariable adjustment, OS was similar for total thyroidectomy vs. lobectomy in patients with tumors 1.0–4.0 cm (HR 0.96 [0.84–1.09], p=0.54), and when stratified by tumor size: 1.0–2.0 cm (HR 1.05 [0.88–1.26], p=0.61) and 2.1–4.0 cm (HR 0.89 [0.73–1.07], p=0.21). Older age, male gender, black race, lower income, tumor size, and presence of nodal or distant metastases were independently associated with compromised survival (p<0.0001). Conclusions—Current guidelines suggest total thyroidectomy for PTC tumors >1 cm. However, we did not observe a survival advantage associated with total thyroidectomy compared to lobectomy. These findings call into question whether tumor size should be an absolute indication for total thyroidectomy.