Circulating SHIP2 mRNA as a novel biomarker in the diagnosis and prognosis of gastric cancer.

OBJECTIVE: Previous studies showed the aberrant expression of Src homology 2-containing inositol 5-phosphatase 2 (SHIP2) in GC tissue. However, the exact role of circulating SHIP2 in GC remains unclear. The aim of this manuscript was to analyze potential diagnostic and prognostic value of circulating SHIP2 levels in GC.

PATIENTS AND METHODS: Circulating SHIP2 expression was detected in the plasma of 156 GC patients and 60 healthy controls by qRT-PCR. The receiver operating characteristic (ROC) curves were plotted to explore the reliability of circulating SHIP2 in detecting GC. Survival curves were estimated using the Kaplan-Meier method, and differences between them were evaluated by the log-rank test. The influence of each variable on survival was examined by the Cox multivariate regression analysis.

RESULTS: Our research showed that the expression levels of circulating SHIP2 in plasma of GC patients were lower than in healthy controls (p < 0.05). Decreased circulating SHIP2 mRNA expression was negatively correlated with clinical stage (p = 0.004), lymph node metastasis (p= 0.003) and distant metastasis (p = 0.025). ROC curve analysis showed that circulating SHIP2 may be a useful marker for discriminating cases from healthy controls. In addition, patients with low circulating SHIP2 mRNA level had poorer overall survival than those with high circulating SHIP2 mRNA level (p = 0.006). Moreover, multivariate analysis indicated that the level of circulating SHIP2 mRNA expression was an independent prognostic indicator (p = 0.005) for the survival of patients with GC.

CONCLUSIONS: The present study indicated that decreased plasma SHIP2 mRNA level might be a novel diagnostic and prognostic biomarker for GC patients. This conclusion should be further assessed in randomized clinical trials.