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EIF1AX mutations in fatal non-anaplastic thyroid cancer.

Mutations in DNA damage control (A), RAS/PI3K/AkT/MTOR pathways (B), chromatin modifying genes (C) and receptor tyrosine kinase genes (RTKs) (D) in fatal non-anaplastic thyroid cancer.

List of 410 genes in IMPACT sequencing platform

Supplementary legend

Comparison of the most commonly mutated genes in fatal WDTC compared to nonfatal WDTC (TCGA)is shown in (A). Comparison of the most commonly mutated genes in fatal PDTC compared to nonfatal PDTC is shown in (B).

All IMPACT mutation calls. Tumors previously published by Landa et al (1) are highlighted in blue.

Purpose: Patients with anaplastic thyroid cancer (ATC) have a very high death rate. In contrast, deaths from non-anaplastic thyroid (NAT) cancer are much less common. The genetic alterations in fatal NAT cancers have not been reported.Experimental Design: We performed next-generation sequencing of 410 cancer genes from 57 fatal NAT primary cancers. Results were compared with The Cancer Genome Atlas study (TCGA study) of papillary thyroid cancers (PTCs) and to the genomic changes reported in ATC.Results: There was a very high prevalence of TERT promoter mutations, comparable with that of ATC, and these co-occurred with BRAF and RAS mutations. A high incidence of chromosome 1q gain was seen highlighting its importance in tumor aggressiveness. Two novel fusion genes DLG5–RET and OSBPL1A–BRAF were identified. There was a high frequency of mutations in MED12 and these were mutually exclusive to TERT promoter mutations and also to BRAF and RAS mutations. In addition, a high frequency of mutations in RBM10 was identified and these co-occurred with RAS mutations and PIK3CA mutations. Compared with the PTCs in TCGA, there were higher frequencies of mutations in TP53, POLE, PI3K/AKT/mTOR pathway effectors, SWI/SNF subunits, and histone methyltransferases.Conclusions: These data support a model, whereby fatal NAT cancers arise from well-differentiated tumors through the accumulation of key additional genetic abnormalities. The high rate of TERT promoter mutations, MED12 mutations, RBM10 mutations, and chromosome 1q gain highlight their likely association with tumor virulence. Clin Cancer Res; 23(19); 5970–80. ©2017 AACR.