Detection of gastric cancer using transabdominal ultrasonography is associated with tumor diameter and depth of invasion.

Gastric cancer is occasionally diagnosed using transabdominal ultrasonography (US) during screening or investigation of patients with abdominal symptoms. Therefore, the present study analyzed the association of the tumor diameter, pathological T (pT) staging and depth of invasion with the detection of gastric cancer using US. Patient records were analyzed retrospectively and 13 patients were enrolled, who underwent US screening prior to endoscopic mucosal resection, endoscopic submucosal dissection or surgery. In total, 5 patients were diagnosed with gastric cancer using US (positive detection group), while US was unable to detect the gastric cancer in 8 patients (negative detection group). The tumor diameter and depth of invasion were determined by pathologists. One-way analysis of variance or the χ2 test was performed. Wall thickness in gastric cancer cases ranged between 7 and 20 mm (mean, 12.2±5.9 mm), as measured using abdominal US. The hemoglobin level was significantly lower in the positive detection patients compared with the negative detection patients (P=0.0455). In addition, the diameters of the gastric wall in the negative and positive detection patients were 24.5±16.4 and 54.4±26.2 mm, respectively (P=0.0266). These results indicate that gastric cancer in the positive detection patients were at a more advanced-stage compared with that in the negative detection patients. Furthermore, gastric cancer with a stage over pT2 was diagnosed using abdominal US (P=0.0242), whereas stage pT1a gastric cancer was not detected by abdominal US. Gastric tumors invading deeper than the submucosa were diagnosed using US (P=0.0242). However, the gastric cancer cases limited to the mucosa remained undetected. In conclusion, the detection of gastric cancer correlated well with the tumor diameter, pT staging and depth of invasion.