CLINICOPATHOLOGICAL CHARACTERISTICS AND TREATMENT OUTCOME OF PATIENTS WITH METASTATIC DIFFERENTIATED THYROID CANCER

Abstract

OBJECTIVE: To assess the clinicopathological characteristics and treatment outcomes of metastatic differentiated thyroid cancer (DTC) in our population. 

METHODS: In this retrospective, real world, single centered study was carried out at Aga Khan University Hospital, Karachi, Pakistan. Data from December 2020 to January 2000 was retrieved about 117 patients with metastatic DTC regarding age at diagnosis, gender, tumor size, extent & spread of tumor and its histological characteristic. The treatment they received and the outcome in terms of status at last follow up was also recorded.

RESULTS: Mean age at diagnosis was 46.6±17.2 years with equal male to female ratio (1:1). Most common site of metastasis was lung (n=15; 12.8%) followed by bone (n=11; 9.4%). Papillary carcinoma was the most common subtype (n=105; 89.7%) followed by follicular carcinoma occurring (n=9; 7.7%), hurthle cell carcinoma (n=2; 1.7%) and diffuse sclerosing variant carcinoma (n=1; 0.9%). Tumor size was <4 cm in 54 (46.2%) patients and ≥4 cm in 63 (53.8%) patients. Cervical metastasis was found in 85 (72.6%) patients while extra thyroidal extensions outside the thyroid bed into the surrounding structures was present in 64 (54.7%) patients. The overall survival was 5.6±2.6 years. Ninety-six percent had complete surgical resection followed by radioactive iodine in 107 (91.5%) patients with 65 being given a dose of 150 mCi, 38 given a dose of 100 mCi and 4 given a dose of 50 mCi.

CONCLUSION: Most significant factors in predicting outcome in metastatic DTC are age, extra thyroidal extension of primary tumor and distant metastasis.