The mutation profiles of cell-free DNA in patients with oesophageal squamous cell carcinoma who were responsive and non-responsive to neoadjuvant chemotherapy

BACKGROUND: The aim of this study was to evaluate the clinical value of plasma cell-free DNA (cfDNA) mutation profiles in patients with oesophageal squamous cell carcinoma (OSCC) who received neoadjuvant chemotherapy. METHODS: Twenty-two OSCC patients received neoadjuvant chemotherapy and were divided into two groups according to their response to the therapy. Fifteen patients were in the responsive group, and seven patients were in the non-responsive group. The blood samples were collected, and the plasma cfDNA mutation profiles were sequenced by a cancer gene-targeted next-generation sequencing (NGS) panel. RESULTS: The driver gene molecular mutation burden (MMB) was significantly higher in the non-responsive group compared with the responsive group. Furthermore, we found that the differential MMB included the DNA damage response, Wnt, PI3K, Hippo, RTK/RAS, p53, and AHR pathway. The MMB yielded an area under the receiver operation characteristic (ROC) curve of 0.89 for predicting the response to neoadjuvant chemotherapy. The cfDNA copy number variations (CNVs) yielded an area under ROC curve of 1.0 for predicting the response to neoadjuvant chemotherapy. CONCLUSIONS: The driver gene MMB and CNVs in plasma cfDNA may be potential biomarkers for predicting the response to neoadjuvant chemotherapy in patients with OSCC.