Predictive factors for re-recurrence in papillary thyroid carcinoma following reoperation: a retrospective analysis.

Background: Papillary thyroid carcinoma (PTC) generally has a favorable prognosis; however, recurrence occurs in up to 30% of cases following initial management. Re-recurrence presents additional clinical challenges, making it crucial to distinguish between persistent disease and true recurrence in order to optimize management strategies and improve patient outcomes. Despite its significance, studies focusing on the risk factors for re-recurrence in PTC are limited. This study aimed to identify the risk factors for re-recurrence in PTC patients who underwent total thyroidectomy and central neck dissection, with or without lateral neck dissection, as the initial operation. Methods: A retrospective review was conducted on the medical records of 158 PTC patients who underwent reoperation for recurrence at a single institution between February 2006 and October 2020. Predictive factors for re-recurrence were identified using Cox proportional hazards models and Kaplan-Meier survival analyses. Results: During a median follow-up of 101.3 months after reoperation, re-recurrence occurred in 27 (17.1%) patients. Univariate analysis revealed that initial T4 stage (P=0.006), initial lymph node ratio >0.7 (P=0.049), and unstimulated thyroglobulin (Tg) ≥1 ng/mL (P=0.02) were significantly associated with worse recurrence-free survival after reoperation. In multivariate analysis, T4a stage [vs. T1-T3b; hazard ratio (HR), 2.782; 95% confidence interval (CI): 1.201-6.447; P=0.02] and unstimulated maximal Tg ≥1 ng/mL after reoperation (vs. <1 ng/mL; HR, 2.427; 95% CI: 1.054-5.588; P=0.04) were strong predictors of re-recurrence. Conclusions: Short-term follow-up with appropriate imaging modalities is necessary for patients with T4a stage disease and for those who had elevated Tg levels after the first reoperation due to PTC.