Abstract: Objective To investigate the clinical value of long non-coding RNA (lncRNA 00707), carcinoembryonic antigen (CEA) and carbohydrate antigen (CA19-9) in peripheral blood in the diagnosis of gastric cancer in the elderly patients. Methods The serum samples of 40 patients with gastric cancer confirmed by pathology and 40 healthy subjects were collected. The relative expression level of serum lncRNA 00707 was detected by real-time fluorescence quantitative PCR (RT-qPCR). The levels of CEA, CA19-9 and the biochemical parameters were detected. The diagnostic efficacy of serum lncRNA 00707, CEA and CA19-9 alone and in combination was evaluated by receiver operating characteristic (ROC) curve. Results The expression of lncRNA 00707 was detected by RT-qPCR with high repeatability and stability. The serum level of LncRNA 00707 in the patients with newly diagnosed gastric cancer was significantly higher than that in the healthy subjects, and the combined detection of lncRNA 00707 and CEA could improve the diagnostic efficiency of gastric cancer. The expression level of lncRNA 00707 decreased in the patients with gastric cancer after surgery. Conclusions The expression level of serum lncRNA 00707 in the patients with newly diagnosed gastric cancer is significantly up-regulated. Detection of serum lncRNA 00707 can assist in the diagnosis of gastric cancer, and is expected to become a new target for the diagnosis and treatment of gastric cancer.

Key words: gastric cancer, peripheral blood, lncRNA 00707, real-time fluorescence quantitative PCR