25 Background: Liquid biopsy including circulating tumor cells (CTCs) and cell-free nucleic acids (cfNAs) has offered a minimally invasive approach for detection and measurement of gastric cancer (GC). Reports regarding associations between liquid biopsy and gastric cancer have been emerging rapidly in recent decades, yet their prognostic value still remains paradoxical. Methods: We searched Medline, Embase, Cochrane Central Register of Controlled Trials database for relevant studies that assessed the prognosis significance of CTCs and cfNAs in gastric cancer from peripheral blood(PB). Newcastle-Ottawa Scale (NOS) was used to assess the quality of evidence. Stata 12.0 was used for pooled analysis and subgroup analysis was performed to determine the association of CTCs or cfNAs’ presence and major clinical characteristics. Pooled results were displayed as hazard ratios (HRs) with their 95% confidence intervals (95% CI) with random effect models. Results: We identified 1258 studies, and then 43 were finally eligible for analysis. A total of 3792 patients were included for final evaluation. Pooled analysis showed that detection of certain CTCs, ctDNA or circulating miRNA was associated with poorer overall survival (OS) (CTCs, HR=2.05, 95%CI 1.65-2.55, p < 0.001; circulating miRNA HR=1.74, 95%CI 1.13-2.69, p=0.013; ctDNA, HR=1.77, 95%CI 1.28-2.44, p=0.001) and disease-free survival(DFS) (CTCs, HR=2.92, 95%CI 1.93-4.40, p < 0.001; circulating miRNA, HR=3.30, 95%CI 2.39-4.55, p < 0.001; ctDNA, HR=4.69, 95%CI 2.23-9.86, p < 0.001) of gastric cancer patients, regardless of the disease’s early or late stage. Conclusions: Several high-quality circulating biomarkers or detection methods for gastric cancer prognosis prediction were identified by subgroup analysis, including the Cellsearch system, cytokeratins, miR-20a, miR-200c, etc. Detection of these certain dysregulation circulating markers in patients’ PB indicates poor prognosis with advanced GC patients.
1489P Liquid biopsy forecasted disease progression and indicated therapeutic improvement for gastric cancer patients receiving HER2-targeted regimen
