Circulating tumor DNA (ctDNA) mutation detection
tumor, Tumor, Cancer
TUMOR, TUMOR, MUTATION, CANCER
In this clinical study, we collected biopsy tissue and blood samples from 37 patients (52.9% of all participants) at the Cancer Hospital Chinese Academy of Medical Sciences center. Tumor biopsy tissue samples were collected before neoadjuvant treatment by esophagogastroscopy. Peripheral blood samples were collected at pretreatment (baseline, C1D1, the first day of the first cycle before administration), the end of the first neoadjuvant treatment cycle (C2D1, the first day of the second cycle before administration), the end of the second cycle (C3D1), the end of the third cycle (C4D1), and the end of the fourth cycle (one day before the operation, preO). Tumor-specific mutations were identified from exome sequencing of tumor biopsy tissue-matched white blood cells. On average, 28 (7–50) mutations per patient were selected for the detection of ctDNA in plasma samples using a personalized assay based on Mutation Capsule, a mutation profiling technology [