Comparative survival outcomes of lobectomy versus total thyroidectomy in T1 and T2 papillary thyroid cancer with more than five positive lymph nodes.

The surgical approach for papillary thyroid cancer (PTC) by either lobectomy or total thyroidectomy (TT) has long been a topic of debate, especially for patients with intermediate-risk PTC, such as T1 and T2 stage patients with more than five positive lymph node metastases (LNM). This study analyzed a population-based retrospective cohort of T1 and T2 PTC patients with more than five positive LNM from the SEER database (2004-2017), comparing clinicopathologic features and survival outcomes between those undergoing lobectomy and TT. Cox proportional hazards regression analysis to explore prognostic factors of survival. Propensity score matching (PSM) was used to balance covariates. The study included 5,610 patients, with 5,322 (94.87%) receiving TT and 288 (5.13%) undergoing lobectomy. Patients in the TT group had higher rates of N1b stage diagnoses, multifocal lesions, and more lymph nodes examined and more lymph nodes positive. Survival analysis showed no difference in overall survival (OS) between the groups (p = 0.177), but a significant difference in cancer-specific survival (CSS) (p < 0.001). After 1:1 PSM, there were no significant difference in OS (p = 0.089) and CSS (p = 0.350). Additionally, stratified analysis showed no significant difference in OS and CSS between patients treated with TT plus radioactive iodine (RAI) ablation and those who underwent lobectomy (both p > 0.05). This cohort study suggests that T1 and T2 PTC patients with more than five positive LNM have no additional survival benefit of TT over lobectomy. If RAI ablation is not planned, lobectomy may be an effective alternative.