Clinicopathological and prognostic significance of circulating tumor cells in patients with gastric cancer: A meta-analysis

Abstract

The prognostic significance of circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) in patients with gastric cancer (GC) is controversial. The aims of our meta-analysis are to assess its correlation with clinicopathological characteristics and prognostic significance in GC. PubMed, Embase, the Cochrane database, the Science citation index, the CNKI database and the references of relevant studies were systematically searched (up to November, 2013). Using the random-effect model, the meta-analysis was completed with odds ratio (OR), risk ratio, hazard ratio (HR) and 95% confidence intervals (CI) as effect values. Twenty-six studies containing 2,566 patients with GC were analyzed. The overall analysis showed that the incidence difference of tumor cells (CTCs/DTCs) was significant when comparing the stage I/II group to the stage III/IV group (OR = 0.36, CI [0.23, 0.56]), the Lauren diffuse group to the intestinal group (OR = 2.06, CI [1.06, 4.00]), the poorly differentiated group to the well/moderate group (OR = 1.65, CI [1.10, 2.50]), the lymphatic involvement positive group to the positive group (OR = 2.92, CI [1.00, 8.55]). The detection of CTCs/DTCs was significantly related with the disease-free survival of patients (HR = 3.42, CI [2.39, 4.91]) and the detection of CTCs in peripheral blood was significantly related with the overall survival of patients (HR = 2.13, CI [1.13, 4.03]). Our meta-analysis indicates that detection of CTCs/DTCs is associated with prognosis for patients with GC and thus could act as a basis for GC staging. What's new? Tumor cells that make their way into the bloodstream or bone marrow are known, respectively as circulating tumor cells (CTCs) and disseminated tumor cells (DTCs). In gastric cancer, both CTCs and DTCs are possible indicators of poor outcome, though their prognostic significance is controversial. Following assessment of correlations between CTCs, DTCs, and gastric cancer prognosis, the authors of the present meta-analysis conclude that the detection of the wayward cells could assist with gastric cancer staging. Correlations were significant specifically between overall survival and CTC detection in peripheral blood and between disease-free survival and both CTC and DTC detection.