Technology in Cancer Research & Treatment (Dec 2021)

Tumor Mutational Burden as a Biomarker for Advanced Biliary Tract Cancer

  • Hongsik Kim MD,
  • Hana Kim MD,
  • Ryul Kim MD, PhD,
  • Hyunji Jo MD,
  • Hye Ryeon Kim MD,
  • Joohyun Hong MD, PhD,
  • Joon Oh Park MD, PhD,
  • Young Suk Park MD, PhD,
  • Seung Tae Kim MD, PhD

DOI
https://doi.org/10.1177/15330338211062324
Journal volume & issue
Vol. 20

Abstract

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Background : High tumor mutational burden (TMB-H) has been reported as a predictive marker to immunotherapy or prognostic marker in various tumor types. However, there has been little study of the role of TMB-H in advanced biliary tract cancer (BTC). Methods : We analyzed 119 advanced BTC patients who received Gemcitabine/Cisplatin (GP) as a first-line treatment between November 2019 and April 2021. Next-generation sequencing (NGS), including TMB analysis, as a routine clinical practice was performed in 119 patients. The TruSight TM Oncology 500 assay from Illumina was used as a cancer panel. Results : Among 119 patients, 18 (18.5%) had a tumor with high TMB (≥ 10 Muts/Mb). There were no significant differences between the status of TMB and clinical outcomes with GP, including objective response rate (ORR) ( P = .126), disease control rate (DCR) ( p = .454), and median progression-free survival (PFS) ( p = .599). The median overall survival (OS) was not different between patients with TMB-H and no TMB-H ( p = .430). In subgroup analysis of 32 patients receiving immune checkpoint inhibitor (ICIs), there were significant differences in ORR ( p = .034) and median PFS ( p = .025) with ICIs between patients with and without TMB-H. Conclusions : This study revealed that TMB-H in advanced BTCs did not have a prognostic or role in the standard first-line treatment. However, TMB-H might be a predictive biomarker for response to ICIs in advanced BTC.