Prophylactic central lymph node dissection for low-risk papillary thyroid cancer-Impact on subsequent therapy.

[BACKGROUND] For small papillary thyroid cancers (PTCs) with no lateral nodal involvement, American Thyroid Association guidelines recommend performing prophylactic central lymph node dissection (pCLND) if it influences further management. Our cohort study explored to what extent performing pCLND for small PTCs can de-escalate subsequent therapy including completion thyroidectomy and adjuvant radioactive iodine (RAI) ablation.

[METHODS] Adults with T1, T2, and cN0 PTCs were identified from 42 centers across the prospectively maintained Australian and New Zealand Thyroid Cancer Registry (ANZTCR) between 2017 and 2023. Patients were excluded if they had clinical nodal involvement or distant metastases. Subsequent therapy and complication rates were compared between patients with and without pCLND.

[RESULTS] Out of 1290 patients with T1, T2, and cN0 PTCs (78% female and median age 53 years), 660 (51%) received a total thyroidectomy and 630 (49%) received a hemithyroidectomy. Prophylactic CLND was performed for 477 patients (37%) and 36% uncovered occult lymph node metastases. After adjusting for differences in age, sex, and tumor characteristics, absence of lymph node metastasis after pCLND was independently associated with fewer completion thyroidectomies (adjusted relative risk [aRR] = 0.65 and p = 0.008) and reduced RAI ablation (aRR 0.55 and p < 0.001). Additionally, pCLND was not associated with higher risks of recurrent laryngeal nerve injury (p = 0.33), temporary hypocalcemia (p = 0.21), or permanent hypoparathyroidism (p = 0.48).

[CONCLUSIONS] In specialized settings across Australia and New Zealand, identifying negative lymph nodes from pCLND is associated with reduced completion thyroidectomies and RAI ablation amongst low risk cN0 PTCs. There were no additional complications rates when performed by experienced thyroid surgeons.