Circulating serum exosomal as a novel biomarker for early diagnosis of gastric cancer.

Gastric cancer (GC) is one of the common malignant tumors with high mortality. The abundance of miRNAs in serum exosomes has proved to have a high application value as a new noninvasive diagnostic method. The purpose of this study was to investigate whether serum exosomal could be used as a new biomarker for early diagnosis of GC and evaluate its clinical application value by detecting the expression of serum exosomal in 131 patients with primary GC and 122 healthy controls by real-time quantitative (qRT)-PCR. The results showed that the expression level of serum exosomal in GC patients was significantly lower than that in normal controls (p < 0.0001). In addition, the level was closely correlated with lymph node metastasis and tumor node metastasis stage of GC patients. The area under the curve for serum exosomal was 0.829, significantly higher than for other indicators. Furthermore, combined detection of serum exosomal , CEA and CA19-9 was more sensitive than any of the three alone or any pair. These results showed that serum exosomal could be used as a novel new tumor biomarker to improve diagnostic efficiency in GC.