Endocrine Abstracts

JOINT1827

Introduction: Advanced thyroid cancer is a rare disease with heterogeneous clinical and pathological characteristics. There is insufficient knowledge regarding this condition. The aim of our study is to investigate the clinicopathological features of advanced-stage thyroid cancer cases at our center.

Method: This retrospective, single-center study identified patients with advanced-stage thyroid cancer through medical records and electronic hospital systems. Demographic data, comorbidities, preoperative ultrasonographic findings, pathological results, treatments, and follow-up information were recorded. Clinicopathological evaluation was performed using descriptive statistics.

Results: A total of 16 patients were included in the study. The mean age of the patients was 61 (±17). 56.3% of the patients were female. Preoperative ultrasonographic examination was available for 8 patients. The average largest nodule diameter was 5 (±3) mm. Hyperechogenicity was found in 12.5%, cystic areas in 25%, hypoechoic halo in 12.5%, and calcifications in 37.5% of the patients, while 12.5% had a well-defined border. 37.5% underwent total thyroidectomy only, while remaining had total thyroidectomy combined with neck dissection. Papillary thyroid carcinoma(PTK) was diagnosed in 9 (56.3%) cases, medullary carcinoma in 2 cases, while anaplastic thyroid carcinoma(ATC)+papillary microcarcinoma, ATC+PTK, follicular carcinoma+papillary microcarcinoma, follicular carcinoma, and Hurthle cell carcinoma were each identified in 1 case. The average tumor size was 37 mm (±23). Among pathological high-risk features, lymphovascular invasion was present in 61.5% and extrathyroidal extension in 63.6%. A papillary carcinoma case exhibited Tall-cell variant, perineural invasion, and BRAFV600E mutation. Distant organ metastasis was present in 5 patients, with lung and bone being the most common. According to the ATA risk score, 12.5% of patients were classified as low, 50.0% as intermediate, and 37.5% as high risk. 75.0% (12 patients) received radioactive iodine (RAI) therapy. The patients who received RAI had a total average dose of 278 mCi (±220). Residual tissue was observed in 4 (30.8%) patients on post-surgical 131-Iodine whole-body scan (WBS). DOTA-PET was used in medullary cancer post-surgery, and FDG-PET in other types, with 3 (18.8%) patients showing uptake. 2 cases showed WBS positive and PET negative results, while 3 cases showed PET positive and WBS negative. 25% of the patients received targeted therapy. The median overall survival after surgery was 97 months.

Conclusion: In our country, advanced thyroid cancer most commonly presents with a papillary histology. 131-Iodine whole-body scan and PET scans may yield false-negative results during follow-up. Targeted therapy is an important treatment option. The survival rate and response to treatment are favorable.