Genomic alterations in biliary tract cancer predict prognosis and immunotherapy outcomes

• DOI: 10.1136/jitc-2021-003214
• Publication Date: 2021-11-18T16:33:22Z
• Authors: Xiaofeng Chen; Deqiang Wang; Jing Liu; Jingrong Qiu; Jun Zhou; Jieer Ying; Yan Shi; Zhaoxia Wang; Haizhou Lou; Jiuwei Cui; Jingdong Zhang; Yunpeng Liu; Fengjiao Zhao; Lanlan Pan; Jianyi Zhao; Dongqin Zhu; Shiqing Chen; Xiangcheng Li; Xue Li; Liuqing Zhu; Yang Shao; Yongqian Shu
• Keywords: Adult; Aged, 80 and over; Male; Neoplasms. Tumors. Oncology. Including cancer and carcinogens; Genomics; Middle Aged; Prognosis; 3. Good health; 03 medical and health sciences; Biliary Tract Neoplasms; 0302 clinical medicine; Immunotherapy Biomarkers; Tumor Microenvironment; Humans; Female; Immunotherapy; RC254-282; Aged; Retrospective Studies

BackgroundRecently, immunotherapy with immune checkpoint inhibitors (ICIs) has shown promising efficacy in biliary tract cancer (BTC), which includes gallbladder cancer (GBC) and cholangiocarcinoma (CHOL). Understanding the association between immunotherapy outcomes and the genomic profile of advanced BTC may further improve the clinical benefits from immunotherapy.MethodsGenomic tumor DNA was isolated from 98 Chinese patients with advanced BTC and used for targeted next-generation sequencing of 416 cancer-related genes to identify the genomic alterations common to advanced BTC. Thirty-four patients had received ICI camrelizumab plus gemcitabine and oxaliplatin (from theNCT03486678trial) as a first-line treatment. Tumor-infiltrating immune cells were evaluated using immunofluorescence staining.ResultsKRAS and TP53 mutations were much more frequent in the advanced-stage BTC cohort than in other cohorts with mostly early stage disease. Specifically, KRAS-TP53 co-mutations were favored in advanced CHOL, with a favorable response to immunotherapy, while single KRAS mutations predicted poor prognosis and immunotherapy outcomes for CHOL. Compared with GBC, CHOL had more mutations in genes involved in KRAS signaling; a high mutation load in these genes correlated with poor immunotherapy outcomes and may subsequently cause inferior immunotherapy outcomes for CHOL relative to GBC. Furthermore, a genomic signature including 11 genes was developed; their mutated subtype was associated with poor prognosis and immunotherapy outcomes in both CHOL and GBC. Transcriptome analyses suggested immune dysfunction in the signature mutated subtype, which was validated by tumor microenvironment (TME) evaluation based on detection of immune cell infiltration. Importantly, the signature wild-type subtype with favorable TME may be an advantageous population of immunotherapy.ConclusionsGenomic alterations in advanced BTC were associated with specific prognosis and immunotherapy outcomes. Combining genomic classification with TME evaluation further improved the stratification of immunotherapy outcomes.