Background: At our institution, thyroid lobectomy is employed as a definitive operation for unifocal intrathyroidal low risk cancers and thus completion thyroidectomy is rarely performed. The purpose of this study was to identify the indications for selective completion thyroidectomy and to report oncologic outcomes.
Methods: A retrospective review was performed to identify patients who underwent planned completion thyroidectomy for well-differentiated thyroid carcinoma (WDTC) from 2001 to 2010 based on initial lobectomy pathology. Assessment for risk of recurrence was based on the American Thyroid Association Initial Risk Stratification.
Results: During the 10-year study period, 79 patients underwent completion thyroidectomy for WDTC. Forty-four (56 %) patients were low risk and 35 (44 %) were intermediate risk. Completion thyroidectomy was recommended for 64 patients, whereas 15 patients were given an option of surveillance but ultimately decided to have surgery. Patients in the "recommended group" had more T3 tumors and fewer T1a tumors (p = 0.005 and 0.006, respectively). These patients also were more likely to be intermediate risk (p = 0.008) and to present with aggressive histology (p = 0.002). The rate of contralateral tumors (n = 27) was similar between both groups (35 and 33 %, respectively). Contralateral cancers were micropapillary in 24 of 27 (89 %) patients, 10 (40 %) of whom had multifocal disease. There were two pulmonary recurrences and no local-regional recurrences (median follow-up of 42.3 months).
Conclusions: Completion thyroidectomy is infrequent and performed for a select group of intermediate and low risk WDTCs at our institution with low recurrence rates. Incidental multifocal and unifocal contralateral cancers are common after completion thyroidectomy.