Central lymph node dissection and permanent hypoparathyroidism after total thyroidectomy for papillary thyroid cancer: population-based study.

Abstract

BACKGROUND\nPapillary thyroid cancer is treated with total/near-total thyroidectomy (TT) with or without central lymph node dissection (CLND), depending on risk factors and tumour size. Balancing the risk of disease recurrence and surgical morbidity remains a challenge. A population-based nationwide study was undertaken to evaluate the risk of permanent hypoparathyroidism associated with CLND.\n\n\nMETHOD\nData on patients with stage pT1-3 papillary thyroid cancer, who underwent TT with or without CLND between 1 July 2004 and 30 June 2014 were retrieved from the Scandinavian Quality Register for Thyroid, Parathyroid and Adrenal Surgery. Drug use was ascertained by cross-linking with the Swedish Prescribed Drug Register. Permanent hypoparathyroidism was defined as treatment with active D vitamin or oral calcium drugs for more than 6\u2009months after surgery. Data were analysed separately for all patients and those who underwent TT\u2009+\u2009CLND. Univariable and multivariable logistic regression analyses were done, yielding odds ratios (ORs) with 95 per cent confidence intervals.\n\n\nRESULTS\nA total of 722 patients were included in the study. Permanent hypoparathyroidism was more common in the TT\u2009+\u2009CLND group than the TT group: 30 of 265 patients (6·6 per cent) versus six of 457 (2·3 per cent) (P\u2009=\xa00·011). In multivariable logistic regression analysis, CLND was a risk factor for permanent hypoparathyroidism (OR 3·74, 95 per cent c.i. 1·46 to 9·59, based on use of combined therapy 6\u2009months after surgery). In patients who had TT\u2009+\u2009CLND, node negativity was associated with a risk of permanent hypoparathyroidism (OR 3·08, 1·31 to 7·25).\n\n\nCONCLUSION\nCLND is an independent risk factor for permanent hypoparathyroidism. Node negativity is associated with a higher risk of permanent hypoparathyroidism.