Prophylactic central neck dissection for papillary thyroid cancer.

BACKGROUND Prophylactic central neck dissection (CND) for papillary thyroid cancer (PTC) remains controversial. The aim of this study was to examine whether prophylactic CND for PTC affected long-term survival and locoregional control. METHODS This was a retrospective cohort study of patients who underwent total thyroidectomy (TT) with bilateral prophylactic CND. They were compared with patients who had TT without CND. Personalized adjuvant radioiodine treatment was used in both groups. Primary outcomes were overall and disease-specific survival, and locoregional control. Secondary outcomes were number of patients with negative serum thyroglobulin levels, and morbidity. RESULTS Of 640 patients with PTC included in this study, 282 (treated in 1993-1997) had TT without CND and 358 (treated in 1998-2002) underwent TT with CND. The 10-year disease-specific survival rate for patients who had TT without CND was 92·5 per cent compared with 98·0 per cent in patients with CND (P = 0·034), and the locoregional control rate was 87·6 and 94·5 per cent respectively (P = 0·003). In multivariable analysis, extrathyroidal extension was an independent predictive factor for locoregional recurrence (odds ratio 12·47, 95 per cent confidence interval 6·74 to 23·06; P < 0·001), whereas CND was an independent predictive factor for improved locoregional control at 10 years after surgery (odds ratio 0·21, 0·11 to 0·41; P < 0·001). No differences were seen in the rates of permanent hypoparathyroidism or recurrent laryngeal nerve injury between the groups. CONCLUSION Bilateral prophylactic CND for staging of the neck in PTC, followed by personalized adjuvant radioiodine treatment, improved both 10-year disease-specific survival and locoregional control, without increasing the risk of permanent morbidity. REGISTRATION NUMBER NCT01510002 (http://www.clinicaltrials.gov).