Abstract 370P
Background
In this study, we examined the TMB landscape of 5,660 pan-cancer cases in Chinese population, using NGS panel. We established cancer-specific and histology-specific biological pathways associated with the TMB status. In addition, as a proof on concept, an unsupervised algorithm was conducted using stepwise logistic regression to generate TMB-predicting signatures from both lung adenocarcinoma and lung squamous cell carcinoma.
Methods
Patients: 5,660 Chinese cancer patients across 11 cancer types Panel: Targeted sequencing was performed on tissue samples using a panel consisting of 295 or 520 cancer-related genes, spanning 1.4 and 1.6Mb of human genome, respectively. An average sequencing depth of 1,000X and 10,000x were achieved for tissue and plasma samples, respectively. Tumor mutation burden: calculated as the ratio of mutation count to the size of coding region of the panel, excluding CNV, fusions, large genomic rearrangements and mutations occurring on the kinase domain of EGFR and ALK.
Results
Across the 11 cancer types included in the analysis, lung squamous cell carcinoma had the highest average TMB, whereas sarcoma has the lowest TMB. High microsatellite instability, DNA damage response deficiency, and homologous recombination repair deficiency indicated significantly higher TMB.The independent predictive power for TMB 26 biological pathways was tested in 11 cancer types. Mismatch repair, DNA damage response, homologous recombination repair, and PI3K-AKT signaling pathway were most commonly correlated with high-TMB. In contrast, ERBB signaling pathway, and adhesion-related pathways were most commonly correlated with low-TMB. Moreover, we developed a 23- and 16-gene signature for TMB prediction for LUAD and LUSC, respectively, with 12 genes shared by both signatures, indicating a histology- specific mechanism for driving high- TMB in lung cancer.
Conclusions
The findings extended the knowledge of the underlying biological mechanisms for high TMB and might be helpful for developing more precise and accessible TMB assessment panels and algorithms in more cancer types.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Burning Rock Biotech.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
371P - Clinical utility of Encyclopedic tumour analysis to treat patients advanced refractory head and neck cancers
Presenter: Rajnish Nagarkar
Session: Poster display session
Resources:
Abstract
372P - Real-world fusion landscape in advanced Chinese pancreatic cancer using next generation sequecing: A multicenter study
Presenter: Yiyu Shen
Session: Poster display session
Resources:
Abstract
373P - Molecular profiling of non-small cell lung cancer (NSCLC) in Asia with targeted next-generation sequencing (NGS): Interim analysis of a co-operative group study (ATORG-001)
Presenter: Aaron Tan
Session: Poster display session
Resources:
Abstract
374P - Circulating tumour DNA (ctDNA) identifies actionable genetic alterations in Middle Eastern and Asian (MEA) patients diagnosed with carcinoma of unknown primary (CUP)
Presenter: Nir Peled
Session: Poster display session
Resources:
Abstract
375P - Whole-exome sequencing of tumour-only samples reveals the association between somatic alterations and clinical features in pancreatic cancer
Presenter: Huixin Lin
Session: Poster display session
Resources:
Abstract
376P - Adoption of molecular testing in breast cancer in a tertiary care center in a developing country
Presenter: Prasanta Dash
Session: Poster display session
Resources:
Abstract
377P - NGS in advanced NSCLC in a developing country: Ready for prime time?
Presenter: Amrith B P
Session: Poster display session
Resources:
Abstract
378P - Germline BRCA1/2 testing: Trend in Tan Tock Seng Hospital Singapore
Presenter: Chia Wei Lim
Session: Poster display session
Resources:
Abstract
379P - Study of germline mutations in high risk cancer patients from a tertiary care center in India
Presenter: Padmaj Kulkarni
Session: Poster display session
Resources:
Abstract
380P - Ventricular–Subventricular zone involvement: A predictive factor for survival in glioblastoma
Presenter: Vibhay Pareek
Session: Poster display session
Resources:
Abstract