A Panel of Circulating microRNAs as a Potential Biomarker for the Early Detection of Gastric Cancer.

Background: The high mortality rate of Gastric Cancer (GC) is a consequence of delayed diagnosis. The early diagnosis of GC could increase the five-year survival rate among patients. We aimed to find a panel of microRNAs (miRNA) for the detection of GC in the early stages. Methods: In this case-control study, we selected consistently upregulated miRNAs from the results of 12 high-throughput miRNA profiling studies in GC. In the profiling phase, the differential expressions of 13 candidate miRNAs were analyzed by quantitative reverse-transcription PCR (qRT-PCR) in two pooled RNA samples prepared from the plasma of eight GC patients and eight matched controls. In the validation phase, significantly upregulated miRNAs from the profiling phase were further evaluated in the plasma samples of 97 patients with stage I-IV gastric adenocarcinoma and 100 healthy controls. Results: In the profiling phase, six miRNAs (miR-18a, 21, 25, 92a, 125b and 221) were significantly upregulated in the GC patients compared to the controls (p<0.05). However, in the validation phase, only significant up-regulation of miR-18a, 21 and 125b was confirmed (p<0.05). A panel of miR-18a/21/125b was able to detect GC patients with stage I-IV from the controls (p<0.001; AUC=0.92, sensitivity=86%; specificity=85%). In addition, the panel could distinguish the early-stage GC (I+II) from the control group with an AUC of 0.83, a sensitivity of 83%, and a specificity of 75%. Conclusion: A panel of circulating miR18a/21/125b could be suggested as a potential biomarker for the early detection of GC.