Many diseases can mimic the symptoms of gastric cancer (GC). Therefore, misdiagnosis of GC is common. Our preliminary sequencing analysis revealed the altered expression of circSLIT2 in GC. In this study, we further explored the role of circSLIT2 in GC.

The research subjects included GC patients, patients with irritable bowel syndrome (IBS), patients with gastric ulcer (GU), patients with gastric tuberculosis (GT), patients with Crohn’s disease (CD), and healthy controls (HC). Accumulation of circSLIT2 RNA in both tissue and plasma samples was determined with RT-qPCR. The diagnostic and prognostic values of circSLIT2 for GC were explored by performing ROC and survival curve analysis. The χ2-test was applied for association analysis.

Increased circSLIT2 RNA accumulation was observed in GC tissues compared to non-tumor tissues. Compared to the HC group, increased plasma circSLIT2 RNA accumulation was only observed in the GC group, but not in the IBS, GU, GT, and CD groups. Plasma circSLIT2 showed a positive correlation with circSLIT2 in GC tissues but not circSLIT2 in non-tumor tissues. Using increased plasma circSLIT2 as a biomarker, GC patients were effectively separated from other disease groups and the HC group. Survival curve analysis revealed that most patients who died during the 5‑year follow-up had high levels of circSLIT2 accumulation in GC tissues and plasma. CircSLIT2 in plasma and GC tissue was only closely associated with distant tumor metastases, but not other clinical factors.

Increased circSLIT2 accumulation may serve as a novel diagnostic and prognostic biomarker for GC.