Excellent Prognosis of Central Lymph Node Recurrence‐Free Survival for cN0M0 Papillary Thyroid Carcinoma Patients Who Underwent Routine Prophylactic Central Node Dissection

Abstract Introduction In Japan, prophylactic central node dissection (p‐CND) for papillary thyroid carcinoma (PTC) has been routinely performed in many institutions, including ours (Kuma Hospital, Japan). We evaluated the recurrence to a central lymph node in patients with cN0M0 PTC who underwent routine p‐CND. Materials and methods We enrolled 4301 patients with cN0M0 PTC who underwent an initial surgery between 1987 and 2005 (median age 51 years). The postoperative follow‐up periods ranged from 4 to 362 months (median 164 months). Only 15 patients underwent radioactive iodine (RAI) ablation (≥30 mCi) after total or near total thyroidectomy. Results Of the 4301 patients with N0M0 PTC who underwent p‐CND, 2548 (59%) were diagnosed as pN1a on postoperative pathological examination. To date, only 52 cases (1.2%) showed recurrence to a central lymph node. The 10‐year and 20‐year central node recurrence‐free survival rates were excellent at 99.1 and 98.2%, respectively. On multivariate analysis, age ≥55 years, significant extrathyroid extension, tumor size >2 cm, and ≥5 pathologically confirmed central node metastases (but not the presence of central node metastasis) independently affected central node recurrence. Conclusions Under the situation of routine p‐CND, the central node recurrence‐free survival of cN0M0 PTC is excellent. However, future studies, including double‐arm studies from Japan, should examine whether the omission of p‐CND cN0M0 PTC is appropriate without RAI ablation in consideration of various factors, including the pros and cons of p‐CND.