Anaplastic Thyroid Carcinoma in the Modern Era: A Population-Based Provincial Analysis

Anaplastic thyroid carcinoma (ATC) is a rare and aggressive malignancy. The purpose of this study was to update the outcomes of ATC in a large provincial database in a modern cohort.

All patients diagnosed with ATC in British Columbia between 2000 and 2022 were included in this retrospective analysis. Charts were reviewed for demographic, staging, treatment, and outcomes data. Statistical analysis was performed using the Kaplan-Meier method for overall survival. The Fine and Gray method was used to determine factors associated with progression.

A total of 127 patients were included, with a median age of 73 years. At diagnosis, 22% had stage IVA, 42% stage IVB, and 36% stage IVC disease. Surgery was performed in 43% of patients, and 66% received radiotherapy. Molecular testing was conducted in 13%, with 5 patients testing positive for BRAF mutations. Chemotherapy was used in 15 patients, either concurrently with radiotherapy or palliatively. Median OS was 5.7 months (stage IVA), 4.3 months (IVB), and 2.5 months (IVC). Improved OS was associated with better ECOG performance status, surgery, radiotherapy, and higher radiation doses (P<0.05). Improved progression-free survival was linked to better ECOG status, absence of metastases, and higher radiation dose (P<0.05). Only 3% of patients survived longer than 3 years.

In this large population-based cohort, ATC remains associated with poor survival, with outcomes strongly influenced by stage and performance status at diagnosis. Surgery and radiotherapy, particularly higher radiation doses, were associated with improved survival outcomes in selected patients.