Prognostic value of FNA-Tg for local recurrence following lateral neck dissection in papillary thyroid carcinoma

Lymph node metastasis (LNM) characterized by high thyroglobulin measurement through fine-needle aspiration (FNA-Tg) is correlated with elevated tumor burden in papillary thyroid carcinoma (PTC). However, the prognostic significance of FNA-Tg remains incompletely understood. The aim of this study was to determine the prognostic significance of FNA-Tg for stratification of patients at high risk of local recurrence following therapeutic lateral neck dissection (LND) in PTC.

This study reviewed medical records of PTC patients with suspected lateral LNM, who underwent FNA-Tg and therapeutic LND. Logistic regression analyses were used to assess the relationships between clinical outcomes and FNA-Tg in lateral LNM. The prognostic value was evaluated using Cox regression and Kaplan-Meier survival curve analyses. Receiver operating characteristic (ROC) curve analysis was used to determine the cut-off values.

The median FNA-Tg levels of metastatic LNs were 500.00 ng/mL and 328.40 ng/mL in patients with and without recurrence, respectively. Multivariate analysis revealed that FNA-Tg > 397.00 ng/mL, multifocality, and lateral lymph nodes ratio (LLNR) > 0.161 as independent risk factors for local recurrence or persistence (p < 0.05). Notably, an FNA-Tg cut-off value of 397.00 ng/mL combined with multifocality and LLNR had a higher predictive value with an area under the ROC curve of 0.912. Additionally, all the three factors were associated with shorter recurrence-free survival (p < 0.05).

As an independent preoperative risk factor for predicting local recurrence or persistence, FNA-Tg assisted in guiding the extent of therapeutic LND and identifying patients at high-risk of postoperative recurrence.