测定血浆外泌体circLPAR1在胃癌患者血清中的表达水平，分析circLPAR1在胃癌中的诊断及预后评估中的临床价值。

采用回顾性队列研究设计，选取2018年3月至2019年3月于安徽医科大学第一附属医院东城院区首次确诊的胃癌患者98例，同期选择慢性胃炎患者60例，健康体检者60例。实时荧光定量聚合酶链反应法检测各组血浆外泌体circLPAR1表达水平，根据表达水平分为circLPAR1高表达组和低表达组。分析血浆外泌体circLPAR1、血清癌胚抗原（CEA）及糖类抗原19-9（CA19-9）在胃癌中的诊断价值。分析血浆外泌体circLPAR1与胃癌患者临床病理特征的关系，Kaplan-Meier法绘制生存率曲线。

胃癌患者血浆外泌体circLPAR1表达水平低于慢性胃炎患者和健康体检者，差异有统计学意义（P<0.05）。血浆外泌体circLPAR1水平与组织分化、肿瘤直径、血管浸润、淋巴结转移、TNM分期相关（P<0.05），血清外泌体circLPAR1高表达组的胃癌患者，平均生存时间长于circLPAR1低表达组。受试者工作特征（ROC）曲线分析显示，血浆外泌体circLPAR1指标下的ROC曲线下面积（AUC）为0.960（95% CI 0.916~0.984），明显高于单一血清CEA检测AUC值0.708（95% CI 0.630~0.777）和单一血清CA19-9检测AUC值0.724（95% CI 0.647~0.792）。

胃癌患者血浆外泌体circLPAR表达水平升高，其表达水平与胃癌患者临床病理特征、预后有关，对诊断胃癌具有较高的灵敏度、特异度，具有一定临床应用价值。

To measure the expression level of plasma exosome circLPAR1 in the serum of gastric cancer patients, and to analyze the clinical value of circLPAR1 in the diagnosis and prognosis assessment of gastric cancer.

A retrospective cohort study design was adopted. A total of 98 gastric cancer patients newly diagnosed at the Dongcheng Campus of the First Affiliated Hospital of Anhui Medical University from March 2018 to March 2019 were selected as the research subjects. At the same time, 60 patients with chronic gastritis and 60 healthy examinees were selected. The expression level of plasma exosomal circLPAR1 in each group was detected by real-time quantitative polymerase chain reaction (RT-qPCR). The diagnostic values of plasma exosomal circLPAR1, serum carcinoembryonic antigen (CEA), and serum carbohydrate antigen 19-9 (CA19-9) in gastric cancer were analyzed. The relationship between plasma exosomal circLPAR1 and the clinicopathological characteristics of gastric cancer patients was analyzed, and the survival curve was drawn by the Kaplan-Meier method.

The expression level of plasma exosomal circLPAR1 in gastric cancer patients was lower than that in patients with chronic gastritis and healthy examinees, with statistically significant differences (P<0.05). The level of plasma exosomal circLPAR1 was correlated with tissue differentiation, tumor diameter, vascular invasion, lymph node metastasis, and TNM stage (P<0.05). The average survival time of gastric cancer patients with high expression of serum exosomal circLPAR1 was longer than that of the low expression group. Receiver operating characteristic (ROC) curve analysis showed that the area under the ROC curve (AUC) of plasma exosomal circLPAR1 was 0.960 (95% CI: 0.916-0.984), which was significantly higher than the AUC value of single serum CEA detection (0.708, 95% CI: 0.630-0.777) and single serum CA19-9 detection (0.724, 95% CI: 0.647-0.792).

The expression level of plasma exosomal circLPAR is increased in gastric cancer patients. The level of plasma exosomal circLPAR is related to the clinicopathological characteristics and prognosis of gastric cancer patients. The detection of plasma exosomal circLPAR has high sensitivity and specificity in the diagnosis of gastric cancer, and has certain clinical application value.