Management of 2-4 cm Papillary Thyroid Carcinoma: Risk of Recurrence Compared to 1-2 cm and >4 cm

Purpose Clinicians still debate how to manage 2-4 cm papillary thyroid carcinoma (PTC). To understand the characteristics and prognosis of these tumors, we compared clinicopathological prognostic factors and prognosis among 1-2 cm, 2-4 cm, and >4 cm PTC. Methods We retrospectively reviewed the medical records of 2,079 patients with primary PTC >1 cm who were diagnosed between 2002 and 2017. Results The patients mean age was 47.9±12.5 years, and 83.2% were women. The follow-up period was 81.1±41.8 months. The tumor recurred in 138 patients (6.6%), and thyroid cancer-related death developed in 3 cases (0.1%). As tumor size increased, so did the proportion of male patients, lymphovascular invasion, resection margin positivity, lymph node (LN) metastasis, metastasis in >5 LNs, T4, N stage, and M stage. Recurrence increased linearly according to tumor size, as did distant metastasis as first recurrence and progression to distant metastasis. Tumor size, N stage, metastasis in >5 LNs, and LN metastasis were significant independent risk factors for PTC recurrence. The recurrence rate of 2-4 cm PTC was 13.4%, while the risk of recurrence was 3 times higher than in 1-2 cm PTC. The 5-year recurrence free survival (RFS) rates of 1-2 cm, 2-4 cm, and >4 cm PTC were 97.0%, 88.0%, and 74.0%, respectively, while the 10-year RFS rates were 95.0%, 84.0%, and 71.0%. Conclusion The 2-4 cm PTC may be pathologically distinct from 1-2 cm PTC and should be treated differently.