NTRK genomic alterations in Latin-American cancer patients.

e15088 Background: The neurotrophic receptor tyrosine kinase genes NTRK1-3 encode the tropomyosin receptor kinase proteins TRKA, TRKB, and TRKC, respectively. TRK fusions lead to overexpression of the chimeric protein, resulting in constitutively active, ligand-independent downstream signaling. NTRKs act as oncogenes, they can be targeted, and it is estimated that they are present in up to 0.3% of tumors. The incidence of actionable alterations in these genes is currently unknown in Latin-American patients. We investigated the presence of NTRK1-3 mutations/rearrangements in 3 independent patient series from several tertiary hospitals from Chile, Brazil and Peru. Methods: 1795 FFPE tumor samples from multiple institutions divided in 3 series were analyzed using 2 NGS panels: Oncomine Focus Assay (OFA; 52 genes) and Oncomine Comprehensive Assay (OCA; 161 genes. Data on NTRK1-3 SNVs, indels, CNVs and fusions was obtained. Bioinformatic workflows were used to study the biologic significance of these alterations. Results: Using OCA (series 1-2), 31 somatic variants were found in gastric, CRC, gallbladder, lung and pancreatic cases out of 300 patients. From these, 13 were located in the tyrosine kinase domain. Using OFA, no NTRK alteration were detected (series 3, 1495 NSCLC cases). Conclusions: NTRK alterations are rare events in Latin-American cancer patients. In 3 series including 1,795 patients, 31 somatic variants were detected. No NTRK fusions or CNVs were identified. The presence of NTRK mutations in the tyrosine kinase domain warrants further research into their potential to benefit from FDA/EMA-approved targeted therapies. [Table: see text]