Next generation sequencing in therapy-related myeloid neoplasms compared to de novo myeloid neoplasms

Therapy-related myeloid neoplasms (t-MN) are frequently categorized according to previous therapy or pattern of cytogenetic abnormalities. Our objective was to evaluate and compare the mutational profile of de novo and t-MN by next generation sequencing.

Sixty-four samples from patients with t-MN, previously treated for a solid tumor (mainly breast), or de novo AML, MDS, MDS/MPN were selected for our study. The library was prepared using diagnostic samples and the TruSight Myeloid sequencing panel targeting 54 genes. Samples were sequenced on a MiSeq. The classification system of the Belgian ComPerMed Expert Panel was used for the biological variant classification.

Taking only pathogenic, probably pathogenic variants and variants of unknown significance into account 141 variants in 33 genes were found in 52 of 64 samples (81%; mean number of variants per patient = 2; range = [1-11]; 67 variants in 25 genes in t-MN and 74 variants in 25 genes in de novo MN). Overall, the most frequently detected variants included TET2 (n = 22), TP53 (n = 12), DNMT3A (n = 10) and FLT3, NPM1, RUNX1 (n = 8 each).

Our study revealed a high variety of variants both in t-MN and de novo MN patients. There was a higher incidence of FLT3 and TP53 variants in t-MN compared to de novo MN.