Gastric cancer is one of the common malignant tumors in China, with relatively high incident
rate and mortality among the population. Surgery is the conventional treatment option for
early and intermediate-stage stage gastric cancer, but postoperative relapse is the major
issue. Circulating tumor DNA (ctDNA) is tumor-derived fragmented DNA with an average size of
166 bp, mixed with cell free DNA (cfDNA) of other sources in blood circulation.ctDNA is
reflecting the most up-to-date status of tumor genome. Hence, it is considered as a new
biomarker for tumor, which can be qualitative, quantitative and used for disease monitoring.
The present clinical trial aims to elucidate the correlation between the serum ctDNA status
and the prognosis of patients with early and intermediate-stage gastric cancer upon surgical
treatment, and explore the possibility of clinical utility of serum ctDNA as a clinical index
to predict postoperative relapse.