Ongoing discussion: Is prophylactic central neck dissection necessary in _cT_1a-b,2N₀ papillary thyroid cancer?

To analyze the central lymph node metastasis (CLNM) rates of patients who underwent prophylactic central lymph node dissection (pCLND) with total thyroidectomy for cT1-2N0 papillary thyroid cancer in our clinic, to evaluate the conditions associated with lymph node metastasis, and to examine the necessity of pCLND in these patient groups.

This study includes a retrospective review of the medical data of patients who underwent bilateral/unilateral central lymph node dissection (CLND) (b/uCLND) with total thyroidectomy in our center between 2013 and 2021, whose fine needle aspiration biopsy result was reported as malignant, who were detected as cT1a-1b-2N0 on thyroid and neck ultrasonography.

Of the 251 patients included in the study, 63 (25%) had CLNM (49 (19.5%) ipsilateral and 14 (5.5%) had contralateral CLNM). Twenty-two (20.1%) of 109 patients with cT1a, 30 (28.3%) of 106 patients with cT1b, and 11 (30.5%) of 36 patients with cT2 had CLNM, and metastasis rates increased with increasing cT category. CLNM rates increased with increasing pT category (p=0.005). CLNM was present in 21 (38.8%) of 54 patients (21.5%) with collision tumors, and metastasis rates increased significantly compared to the presence of a single histopathologic tumor (p=0.006). CLNM rates were higher in patients with multicentric tumor localization than in those with unicentric localization (p=0.006).

Multicentricity, bilaterality, capsule invasion, collision tumors and tumors larger than 1 cm increase the risk of CLNM. uCLND for tumors larger than 1 cm, bCLND for tumors larger than 2 cm can be considered. We believe that patients with unilateral CLNM also have an increased risk of contralateral metastasis.