Molecular analysis of Chinese oesophageal squamous cell carcinoma identifies novel subtypes associated with distinct clinical outcomes.

BACKGROUND

Oesophageal squamous cell carcinoma (ESCC) is a highly heterogeneous cancer with a distinct incidence and prognosis. Molecular events driving ESCC subtypes and prognosis have not been established, and little is known regarding Chinese ESCC patients in Xinjiang, China.

METHODS

Here, we first integrated the genomic and transcriptomic data of 125 Chinese ESCC patients from Xinjiang Tumor Hospital (Urumqi, China). Two independent datasets of GSE53624 and The Cancer Genome Atlas (TCGA) ESCC were used to confirm the results of this study. DNA mutation and overall survival (OS) were analysed independently in the Chinese ESCC cohorts.

FINDINGS

Genomic analyses revealed a consistent mutation signatures and discordance among mutated genes across the different ESCC cohorts. In addition, transcriptomic profiling identified three Chinese ESCC subtypes associated with clinical and molecular attributes, including patient survival, lymph node status and genetic profile. Moreover, Chinese ESCC subtypes have distinct metabolic, inflammatory, metastatic, and cell proliferation features and unique potential therapeutics. Furthermore, the expression of cell cycle- and/or cell proliferation-related genes was higher in cyclin D1 (CCND1)-amplified tumours than in CCND1-normal tumours from Chinese ESCC patients, suggesting that CCND1 amplification promoted cell proliferation.

INTERPRETATION

Our findings provide a framework to facilitate the rational categorization of ESCC in Chinese patients and a foundation for new therapies.

FUNDING

This study was supported by the Research Fund of Key Laboratory of Xinjiang oncology (Grant no.2017D04006) and the Outstanding Youth Science and technology training project fund of Xinjiang, China (Grant no. 2017Q058).