Circulating tumor cells (CTCs) detected by RT-PCR and its prognostic role in gastric cancer: a meta-analysis of published literature.

OBJECTIVE

The prognostic significance of circulating tumor cells (CTCs) is controversial in gastric cancer (GC). We performed a meta-analysis of available studies to assess its prognostic value detected by RT-PCR for patients diagnosed with GC.

METHODS

EMBase, PubMed, Ovid, Web of Science, Cochrane library and Google Scholar database search was conducted on all studies reporting the outcomes of interest. The studies were set up according to the inclusion/exclusion criteria. Meta-analysis was performed by using a random-effects model; hazard ratio (HR), risk ratio (RR) and their 95% confidence intervals (95% CIs) were set as effect measures. The information about trial design, results from the data was independently extracted. Heterogeneity of the studies was tested for each pooled analysis.

RESULTS

Nineteen studies published matched the selection criteria and were included in this meta-analysis. CTCs positivity was significantly associated with poor relapse free survival (RFS) (HR 2.42, 95% CI: [1.94-3.02]; P<0.001) and poor overall survival (OS) (HR 2.42, 95% CI: [1.94-3.02]; P<0.001). CTCs positivity were also significantly associated with regional lymph nodes (RLNs) metastasis (RR 1.42, 95% CI: [1.20-1.68]; p<0.0001), depth of infiltration (RR 1.51, 95% CI: [1.27-1.79]; p<0.0001), vascular invasion (RR  = 1.43, 95% CI: [1.18-1.74], p = 0.0002) and TNM stage(I,II versus III) (RR 0.63, 95% CI [0.48-0.84]; p = 0.001).

CONCLUSION

Preoperative CTCs positivity indicates poor prognosis in patients with gastric cancer, and associated with poor clinicopathological prognostic factors.