Objective:To investigate the serum level of insulin-like growth factor binding protein 7 (IGFBP7) in patients with gastric cancer and its diagnostic significance.Methods:A total of 100 gastric cancer patients (gastric cancer group) including 49 patients with early gastric cancer (early gastric cancer group) , who were hospitalized in Sun Yat-sen University Cancer Center from May to December 2019 were selected as the research subjects, and 94 physical examination subjects during the same period were selected as the normal control group. The levels of serum IGFBP7 were detected by enzyme-linked immunosorbent assay. At the same time, the laboratory carcinoembryonic antigen (CEA) test results were collected. The relationships between the level of serum IGFBP7 and the clinicopathological features of gastric cancer patients were analyzed. The diagnostic value was evaluated by receiver operating characteristic (ROC) curve.Results:The level of serum IGFBP7 in the gastric cancer group was (1.595±0.159) ng/ml, and that in the normal control group was (1.850±0.328) ng/ml, with a statistically significant difference ( t=-0.26, P<0.001) , and among them, the level of serum IGFBP7 in the early gastric cancer group was (1.601±0.153) ng/ml, and there was a statistically significant difference compared with the normal control group ( t=-0.26, P<0.001) . The level of serum CEA in the gastric cancer group was 2.230 (2.043) ng/ml, and that in the normal control group was 1.805 (1.020) ng/ml, with a statistically significant difference ( U=0.45, P=0.004) , and among them, the level of serum CEA in the early gastric cancer group was 2.220 (1.780) ng/ml, and there was a statistically significant difference compared with the normal control group ( U=0.53, P=0.002) . There were no significant correlations between IGFBP7 and CEA level ( χ2=0.36, P=0.547) , age ( χ2=0.16, P=0.688) , gender ( χ2=0.97, P=0.326) , depth of invasion ( χ2=0.30, P=0.585) , lymph node metastasis ( χ2=0.17, P=0.684) , distant metastasis ( χ2=0.09, P=0.767) and TNM stage ( χ2=0.38, P=0.537) . ROC curve analysis showed that the area under the curve (AUC) of IGFBP7 for gastric cancer diagnosis was 0.84 (95% CI: 0.78-0.89) , the AUC of CEA for gastric cancer diagnosis was 0.62 (95% CI: 0.54-0.70) , and there was a statistically significant difference ( Z=4.33, P<0.001) . The AUC of IGFBP7 combined with CEA for gastric cancer diagnosis was 0.85 (95% CI: 0.79-0.90) . Compared with CEA alone, there was a statistically significant difference ( Z=4.97, P<0.001) . Compared with IGFBP7 alone, there was no statistically significant difference ( Z=1.41, P=0.159) . The AUC of IGFBP7 in the diagnosis of early gastric cancer was 0.84 (95% CI: 0.78-0.91) , the AUC of CEA in the diagnosis of early gastric cancer was 0.66 (95% CI: 0.56-0.75) , and there was a statistically significant difference ( Z=3.11, P=0.002) . The AUC of IGFBP7 combined with CEA in the diagnosis of early gastric cancer was 0.85 (95% CI: 0.78-0.91) . Compared with CEA alone, there was a statistically significant difference ( Z=3.54, P<0.001) . Compared with IGFBP7 alone, there was no statistically significant difference ( Z=1.19, P=0.232) . Conclusion:The serum IGFBP7 level of gastric cancer patients is lower than that of normal controls. Compared with CEA, serum IGFBP7 has better diagnostic value for gastric cancer.