The expression and clinical significance of circ_0007167 in patients with gastric cancer
Authors: Zhu Feilong , Wu Yingting , Ye Zhen , Wu Xiaotian , Cao Xueping , Chen Huifen 
Published: May 2024

Background
Gastric cancer (GC) is one of the commonest malignant tumors worldwide including China. Data from epidemiological surveys showed that the new cases of GC were globally increased by 1 million per year, and 800,000 people died from gastric cancer every year. In recent years, it has been found that cyclic RNA plays an important role in the occurrence of GC, and it may be used as an evaluation index for the diagnosis and prognosis of GC. This study was conducted to assess the clinical application value of circ_0007167 for diagnosis and prognosis of GC.
Methods
GC group was collected from September 1, 2019 to November 30, 2020 at the Affiliated Hospital of Nantong University. There were 108 patients with GC confirmed by imaging and pathology, including 20 pairs of plasma from GC patients before and one week after surgery. There were 40 patients with benign gastric lesions and 79 healthy individuals from the physical examination center of the Affiliated Hospital of Nantong University. The expression levels of circ_0007167 in the plasma samples of the three groups were detected using qRT-PCR following validation of the method. The correlations between changes in plasma circ_0007167 levels and the clinical pathological parameters of GC patients were statistically analyzed. Meanwhile, the ROC curves of plasma circ_0007167, CEA and CA19-9 levels were analyzed to study the clinical value of single and combined detection in the diagnosis and prognosis of GC.
Results
The expression level of circ_0007167 in the plasma of patients with GC was significantly higher than that in the benign gastric lesions group and the healthy control group (both p < 0.001). There was no significant difference between benign gastric lesion group and healthy control group (p = 0.328). Further clinicopathologic features showed that plasma circ_0007167 was not related to gender (p = 0.687), age (p = 0.841), and differentiation degree of tumor (p = 0.9), but related to tumor size (p < 0.05), T stage (p < 0.001), metastasis (p < 0.001) and nerve/vascular invasion (p = 0.006). The diagnostic efficacy of ROC curve analysis showed that the area under the curve (AUC) of circ_0007167 was 0.881, significantly higher than that of CA19-9 (AUC = 0.679) and CEA (AUC = 0.698), and the diagnostic efficacy of circ_0007167 was better than that of traditional tumor markers CEA and CA19-9. There was no significant difference in diagnostic efficacy between CEA and CA19-9, but when circ_0007167 was combined with CEA, AUC was 0. 893; when circ_0007167 was combined with CA19-9, AUC was 0. 891; when circ_0007167 was combined with CEA and CA19-9 as diagnostic markers, diagnostic efficiency is the best with AUC = 0.896. The expression of circ_0007167 in plasma of GC patients decreased significantly after operation compared to that before operation (p < 0.001).
Conclusion
Plasma circ_0007167 in patients with GC is superior to traditional tumor markers CEA and CA19-9. Combined detection of circ_0007167 with CEA and CA19-9 can improve the assisted diagnosis of early GC. Moreover, the plasma circ_0007167 was decreased significantly following surgery, suggesting that plasma circ_0007167 may serve as a new biomarker for the diagnosis, treatment, and prognosis evaluation of GC.