Landscape of FGFR2/3 alterations in hepatobiliary malignancies.

Abstract

e16152 Background: Genomic aberrations (GAs) in FGFRs are involved in the pathogenesis of Hepatobiliary Malignancies, and clinical trials have shown efficacy of FGFR inhibitors in treating hepatobiliary malignancies patients with FGFR GAs. However, the molecular profile of FGFR2/3 in hepatobiliary malignancies is still lacking. Here, we focused on mutational landscape of FGFR2/3 GAs in hepatobiliary malignancies. Methods: We prospectively sequenced 876 tumors and matched blood DNA from Chinese and TCGA patients with hepatobiliary malignancies using next-generation sequencing techniques. Comprehensive molecular characterization was analyzed. Results: 13.2% (116/876) hepatobiliary malignancies carried FGFR2/3 GAs, including somatic mutation (56, 6.4%), CNV (41, 4.7%), and fusion (23, 2.62%). In FGFR2/3 mutation cohorts, the five most frequently somatic mutated genes were TP53 (46%), NCOR2 (26%), LRP1B (18%), KMT2C (17%), and FAT1 (16%), except for FGFR2 and FGFR3 gene. For FGFR2/3 wildtype cohorts, the five most frequently mutated genes were TP53 (46%), NCOR2 (13%), CTNNB1 (12%), LRP1B (12%), and ARID1A (10%). 77 mutated genes were significant difference between FGFR2/3 mutation and FGFR2/3 wildtype cohorts, such as NCOR2, KMT2C, FAT1, ROS1 and KMT2B, excluding the FGFR2 and FGFR3 gene. In addition, patients with FGFR2/3 GAs harbored a significantly higher TMB than those in patients without FGFR2/3 GAs (12.6 vs 9.0, p=0.003). There was no significant difference in genomic instability between the FGFR3 mutant group and the wild group (p>0.05), including ploidy, wGII, and ITH. Conclusions: FGFR2/3 GAs are frequently altered in hepatobiliary malignancies. Comprehensive genomic profiling of FGFR2/3 GAs highlights the clinical and therapeutic implication. There were characterized the genomic differences and similarities, stratified by the FGFR2/3 status, which may reflect the hepatobiliary malignancies patients with FGFR2/3 GAs harbored specific molecular mechanism.