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Simple Summary: The analytic appropriateness and general applicability of lymph node-related risk factors used to predict long-term outcomes in patients with papillary thyroid carcinoma need to be validated. This study aimed to assess detailed lymph node-related risk factors and suggest new risk categories. In the present study, using the K-means clustering algorithm, we determined new cutoffs for lymph node variables besides extranodal extension: 0.2 cm and 1.1 cm for the maximal diameter of metastatic lymph node foci, 4 and 13 for the number of metastatic lymph nodes, and 0.28 and 0.58 for the metastatic lymph node ratio; new lymph node risk categories were suggested. The recurrence-free survival curves of each subgroup classified by these newly determined cutoffs showed significant differences. These newly developed risk categories might be considered when redefining risk stratification or staging systems. Background: Lymph node (LN)-related risk factors have been updated to predict long-term outcomes in patients with papillary thyroid carcinoma (PTC). However, those factors' analytic appropriateness and general applicability must be validated. This study aimed to assess LN-related risk factors, and suggest new LN-related risk categories. Methods: This multicenter observational cohort study included 1232 patients with PTC with N1 disease treated with a total thyroidectomy and neck dissection followed by radioactive iodine remnant ablation. Results: The median follow-up duration was 117 months. In the follow-up period, structural recurrence occurred in 225 patients (18.3%). Among LN-related variables, the presence of extranodal extension (p < 0.001), the maximal diameter of metastatic LN foci (p = 0.029), the number of retrieved LNs (p = 0.003), the number of metastatic LNs (p = 0.003), and the metastatic LN ratio (p < 0.001) were independent risk factors for structural recurrence. Since these factors showed a nonlinear association with the hazard ratio of recurrence-free survival (RFS) rates, we calculated their optimal cutoff values using the K-means clustering algorithm, selecting 0.2 cm and 1.1 cm for the maximal diameter of metastatic LN foci, 4 and 13 for the number of metastatic LN, and 0.28 and 0.58 for the metastatic LN ratio. The RFS curves of each subgroup classified by these newly determined cutoff values showed significant differences (p < 0.001). Each LN risk group also showed significantly different RFS rates from the others (p < 0.001). Conclusions: In PTC patients with an N1 classification, our novel LN-related risk estimates may help predict long-term outcomes and design postoperative management and follow-up strategies. After further validation studies based on independent datasets, these risk categories might be considered when redefining risk stratification or staging systems. [ABSTRACT FROM AUTHOR]

Objective: Primary tumour size (PTS) is known to be a significant prognostic factor in patients with papillary thyroid carcinoma (PTC) undergoing thyroidectomy. Although cutoff values of 2 and 4 cm are widely used in surgical extent decision and long‐term outcomes predictions, the effectiveness of arbitrary cutoff values in stratifying patients for target outcomes is questionable. This study aimed to determine new optimal cutoffs of PTS. Design, Patient And Measurements: Patients (n = 529) with PTC who underwent total thyroidectomy were retrospectively reviewed. After risk factor analysis for structural recurrence, the optimal cutoffs of PTS were automatically calculated using restricted cubic spline analysis and X‐tile software. Subgroups were classified based on the newly determined cutoff values. Both the recurrence‐free survival (RFS) and the proportion of patients in each response‐to‐therapy category, using the dynamic risk stratification system (DRS), were compared between the subgroups. Results: PTS was confirmed as an independent risk factor for structural recurrence. The optimal cutoff values were calculated as 1.4 and 3.0 cm. The subgroups stratified using these newly determined cutoffs showed significantly different RFS and DRS based on the response to initial therapy, but the subgroups classified using the cutoffs of 2 and 4 cm did not. Conclusions: The newly determined cutoff values of PTS may be useful in better stratifying patients with PTC undergoing thyroidectomy for target outcomes and can be considered as a new definition in staging and risk stratification systems. [ABSTRACT FROM AUTHOR]

Background For patients with papillary thyroid carcinoma (PTC), lymph node metastasis is associated with an increased recurrence rate. The purpose of this study was to investigate whether the vascular endothelial growth factor (VEGF), microvessel density (MVD), and vascular index (VI) can predict lymph node metastasis in patients with PTC. Methods From January 2011 to October 2011, 202 patients with PTCs underwent preoperative staging ultrasound evaluation. To evaluate vascularity, we measured the VI, VEGF expression, and MVD. Results The VI was significantly correlated with MVD ( p = .009). On multivariate analysis, young age showed a significant correlation with lymph node metastasis ( p < .001; p < .001; p < .001). However, the other clinicopathologic features, VEGF, MVD, and VI failed to show any significant correlations with lymph node metastasis. Conclusion Although the VI showed significant correlation with MVD, it was not significantly correlated to lymph node metastasis. © 2016 Wiley Periodicals, Inc. Head Neck 39: 334-340, 2017 [ABSTRACT FROM AUTHOR]