Next-Generation Sequencing Characterizes the Landscape of Somatic Mutations and Pathways in Metastatic Bile Tract Carcinoma

Purpose. Tumor metastasis remains the leading cause of cancer-related mortality in biliary tract cancer. The etiology and mechanism of bile tract carcinoma metastasis are unclear. Methods. The primary tumor and blood samples of 14 patients with biliary tract cancer were collected, followed by nucleic acid extraction and library construction. Target sequencing with 556 panel genes and WES were performed to detect the hot spot genes variations. Bioinformatics was used to comprehensively analyze the sequencing data of these samples, including the differences of tumor mutation burden and signaling pathways. Results. The results showed that the mutation frequency of TP53 gene was the highest and the mutations of CTNNB1, EPHA7, ARID2, and PIK3CA were only found in metastatic samples. The TMB mean values of metastatic and non-metastatic groups were 12.97 and 10.38 mutations per Mb, respectively. There were significant differences in the enrichment pathways of cellular components between the tumor metastasis and non-metastatic samples. Conclusions. We identified multiple pathway differences, which helps us better understand metastatic biliary tumors and design clinical therapy for personalized medicine.