Surgery for Neck Recurrence of Differentiated Thyroid Cancer: Outcomes and Risk Factors.

Background: Persistent/recurrent disease in the neck is frequent in patients with differentiated thyroid cancer (DTC). Objective: Assess efficacy, safety, and prognostic factors of first neck reoperation in DTC.
Methods: Retrospective study of consecutive patients undergoing neck reoperation for recurrent/persistent DTC in a referral cancer center. Response after reoperation was defined according to the 2015 American Thyroid Association guidelines. Findings: One hundred sixty-one DTC patients were enrolled (64% females, median age 35 years, 96% papillary DTC). Initial stage was pT3 in 43% and pT4 in 10%, pN1 in 74%. Aggressive histology was present in 25% of the patients, in both primary and persistent/recurrent tumor. Four patients had no malignancy in the reoperative specimen, and 1 patient died due to postoperative hematoma and was excluded from further analysis. Following reoperation, 15 patients (10%) had persistent structural disease, 16 (10%) had biochemical incomplete response, 26 (17%) had indeterminate response, and 99 (63%) had complete response (CR), among whom 24 relapsed later. After a median follow-up of 5 years, only 83 patients (53%) had CR without the need for further treatments. The rate of permanent complications was: hypoparathyroidism 2%, laryngeal nerve palsy 0.6%, other 6%. Age ≥45 years, aggressive histology, and lymph node ratio ≥0.6 at initial surgery were independent risk factors for incomplete response after reoperation. Male sex, aggressive histology, and ≥10 metastases at reoperation were independent risk factors of secondary relapse following CR achieved with reoperation.
Conclusion: A careful risk-benefit analysis should guide surgical decision, particularly in patients with risk factors for incomplete response.