Central Lymph Node Status has Significant Prognostic Value in the Clinically Node-Negative Tall-Cell Variant of Papillary Thyroid Cancer Regardless of T-Staging and Radioactive Iodine Administration: First Evidence From a Population-Based Study

摘要

Background The prognostic value of central lymph node (CLN) status in papillary thyroid cancer (PTC) remains controversial. This study aimed to provide the first evidence on this issue for the aggressive tall-cell variant (TCV) subtype. Methods The study identified TCV patients from the Surveillance, Epidemiology, and End Results database. The?Kaplan–Meier?method, log-rank test, and multivariate Cox regression models were used for analysis. Results Of the 744 patients?included, 404 were recorded as N0, which were pathologically or only clinically confirmed. Overall survival (OS) and cancer-specific survival (CSS)?did not differ significantly between the N0 and pN1a patients ( p? >?0.05). To investigate the reason, the N0 patients were subdivided according to the number of examined lymph nodes (ELN). The patients with a N0 diagnosis confirmed by two or more ELNs (N0-e2+) showed significantly better outcomes than the pN1a patients and their N0 counterparts without ELN (N0-e0) ( p? ?0.05). Moreover, the subgroup analyses showed that even among the patients with early T-staging (T1–T2) or receipt of radioactive iodine (RAI) therapy, the N0-e0 patients still demonstrated compromised OS compared with the N0-e2+ group ( p?