Recognizing Persistent Disease in Well-Differentiated Thyroid Cancer and Association with Lymph Node Yield and Ratio.

Abstract

To establish the association between lymph node yield and ratio in neck dissection for well-differentiated thyroid cancer and risk for persistent postoperative disease. Retrospective cohort study of patients undergoing lymphadenectomy for thyroid carcinoma. Tertiary referral center. Included patients underwent central and/or lateral neck dissection for papillary thyroid carcinoma at our institution between 1994 and 2015. They were divided into a persistent disease group with biochemical and structural disease (49 patients) and a disease-free group with no disease after a minimum 2 years of follow-up (175 patients). Demographic characteristics, adjuvant therapy, tumor, and lymph node features were compared. There were no significant differences in demographic characteristics between the groups. The mean nodal yield of patients with central and lateral neck persistence was significantly lower than that of patients remaining disease free (4.8 vs. 11.9: odds ratio [OR] 0.69; 95% CI, 0.59 to 0.8; <i>P</i> < .001; 14.8 vs. 31.0: OR, 0.89; 95% CI, 0.84-0.94; <i>P</i> < .001, respectively). Nodal ratio was higher in patients with persistence in the central and lateral neck (74.2% vs 29.4%: OR, 1.06; 95% CI, 1.04-1.08; <i>P</i> < .001; 54.2% vs 19.8%: OR, 1.08; 95% CI, 1.04-1.12; <i>P</i> < .001, respectively). Lower lymph node yield and higher node ratio from cervical lymph node dissections are associated with persistent disease and have potential applications in surgical adequacy.