Risk Factors for Recurrence of Papillary Thyroid Carcinoma with Clinically Node-Positive Lateral Neck

Papillary thyroid carcinoma (PTC) with clinically node-positive lateral neck is more likely to recur after surgery than node-negative PTC. The present study investigated the risk factors for recurrence in PTC patients with clinically node-positive lateral neck. This study involved 136 patients with pathologically confirmed PTC and a clinically lymph node (LN)-positive lateral neck but no initial distant metastasis who underwent total thyroidectomy with therapeutic central and lateral neck dissection. Clinicopathologic characteristics, intraoperative findings, postoperative thyroglobulin (Tg) levels, and post-treatment recurrences were examined. Univariate and multivariate analyses were performed to identify factors associated with recurrence-free survival (RFS). During a median follow-up of 62 months (range 33-90 months), 27 (19.9 %) patients had locoregional or distant recurrences. Univariate analyses showed that primary tumor size (p = 0.049), recurrent laryngeal nerve invasion (p = 0.035), the maximal size of metastatic LN foci (a parts per thousand yen1.5 cm; p = 0.012), extranodal extension (p = 0.025), total LN ratio (a parts per thousand yen0.26; p = 0.008), American Thyroid Association (ATA) risk categories (p < 0.001), and stimulated serum Tg level (a parts per thousand yen4.4; p < 0.001) at the time of radioactive iodine ablation therapy just after thyroidectomy were significant predictors of RFS. Multivariate analyses showed that the maximal size of metastatic foci (p = 0.037), ATA risk categories (p < 0.001), and stimulated Tg level (p < 0.001) were independent predictors of RFS. Maximal size of metastatic foci, ATA risk categories, and stimulated serum Tg levels are predictive of recurrence after surgery. Careful follow-up of patients with these risk factors is therefore recommended.