Anaplastic thyroid cancer (ATC) is an extremely rare and fatal endocrine malignancy. R0 surgical resection and adjuvant therapy, especially new targeted therapies, increase the life expectancy of patients. Determining the genetic landscape of patients with ATC will provide an advantage to the survival of patients with targeted therapies.

Patients diagnosed with ATC between 2000 and 2023 were retrospectively studied. Biopsy materials were analyzed by Illumina Miseq targeted NGS to assess single nucleotide variations in genes.

A total of 27 patients [21(77%) female, 6(23%) male] were included. The mean age was 68,6 years. Thyroidectomy was performed in 10 patients, debulking surgery in 4 patients, and only biopsy in 13 patients. Genetic analyses could be performed on the biopsy material of thirteen patients, and the variations detected were TP53(69,3%), STK11(30,7%), NRAS(23,1%), BRAF(15,4%), HRAS(15,4%), CDKN2A(15,4%), TERT(7,7%), AKT1 (7,7%). Twenty-six patients died, and only one patient survived. Median overall survival was 158.7 days (50,5 - 266,9 days). When analyzed by Cox regression analysis, there was no statistically significant difference in the effect of patient mutations on median survival (p=0,248). Median survival was 327,5 days for those receiving new targeted therapy and 145.3 days for those not receiving it. The Mann-Whitney U test shows that there is a survival advantage. (p=0,023)

In our study, new targeted therapies have been shown to prolong life expectancy in patients with ATC, supporting the literature. However, the type of somatic mutation detected alone did not affect life expectancies.