[Study on clinical diagnosis, treatment, and prognostic factors of poorly differentiated thyroid cancer]

Objective: To investigate factors associated with overall survival after surgery in patients with poorly differentiated thyroid carcinoma (PDTC). Methods: This retrospective case series study analyzed clinicopathological characteristics and follow-up data of 52 patients with PDTC who underwent surgical treatment at the Department of Thyroid Surgery, the First Affiliated Hospital of Zhengzhou University between January 2015 and April 2024. The cohort included 19 males and 33 females,with an age of (54.2±16.4) years (range: 10 to 79 years). Cumulative survival rates were estimated and survival curves plotted using the Kaplan-Meier method, and differences between groups were compared using the Log-rank test. Independent prognostic factors associated with overall survival (OS) were identified using a multivariable Cox proportional hazards regression model. Results: The 3-year and 5-year OS rates were 65.1% and 53.1%, respectively. Mean and median OS times were 76.3 months and 63.0 months, respectively. Kaplan-Meier survival analysis demonstrated that age (P=0.003), maximum tumor diameter (P=0.003), surgical procedure (P=0.002), extrathyroidal extension (P=0.002), cervical lymph node metastasis (P=0.007), distant metastasis (P=0.011), and Ki-67 index (P=0.003) were significant prognostic factors for OS in patients with PDTC. Multivariable Cox proportional hazards regression analysis demonstrated that total thyroidectomy was an independent protective factor for postoperative OS (HR=0.270, 95%CI: 0.107 to 0.682, P=0.006), whereas age at diagnosis ≥55 years (HR=2.593, 95%CI: 1.062 to 6.330, P=0.036), extrathyroidal extension (HR=4.598, 95%CI: 1.027 to 20.580, P=0.046), and Ki-67 index≥20% (HR=2.725, 95%CI: 1.059 to 7.011, P=0.038) were independent adverse prognostic factors for postoperative OS. Conclusions: Patients aged ≥55 years, those with extrathyroidal extension, and those with a high Ki-67 index (≥20%) have a poorer prognosis, highlighting the need for closer postoperative surveillance and management in these high-risk patients.