Electrogastrographic Study in Patients with Gastric Cancer according to Location and Depth of Invasion

Abstract

Gastric slow waves which reflect neuromuscular activity of stomach, are considered to originate from the circular muscle of the stomach or from the interstitial cells of Cajal on the greater curvature near the junction of the proximal and distal gastric corpus. Therefore, it is suggested that the gastric malignancy occurring at some region of the stomach may affect the gastric myoelectrical activity. Scarse information is available about the changes of myoelectrical activity in patients with gastric cancer. This study was aimed at investigaing the effect of gastric cancer on gastric myoelectrical activity according to the location and depth of invasion. Methods: Seventy patients(mean age: 54.9±12.9yr,M:F=44:26) with gastric cancer and seventy normal controls(mean age: 45.9±11.1yr, M:F=34:36) were included. Gastric myoelectrical activity was recorded via abdominal surface electrodes using an ambulatory electrogastrographic recorder (Digitrapper EGG, Syndics, Irving, TX). The record were analyzed based on running spectral analysis. Electrogastrography was recorded for at least 30-min during fasting and then 30-min after solid test meal(700 Cal, protein 32 gm, fat 15 g, carbohydrate 110 gm). Results: 1) The percentage of normal slow waves(2-4cpm) was 87.5±15.8% in early gastric cancer group(19), 95.4±18.9% in advanced gastric cancer group(81) and 91.3±9.9% in control group(70) in fasting state In postprandial state, the percentages were 85.9±12.7% 89.3±13.9% and 89.7±10.2% respectively. 2) In advanced gastric cancer, there was no statistical difference according to cancer location on gastric myoelectrical activity. 3) The power ratio defined as postprandial slow wave amplitude increment, was normal in most patients between early and advanced cancer group and control group. 4) In 11 patients with antral cancer and partial pyloric obstruction, the percentage of normal slow waves was 93.3±10.9% in fasting state and 92.8±11.2% in postprandial state and amplitude of slow waves in fasting state was significantly higher than in antral cancer without obstruction (p<0.05). Conclusions: There was no significant change in pattern of gastric myoelctrical activity in patients with gastric cancer according to the location and depth of invasion. However, the pyloric obstruction by cancer infiltration produced prominent increase of amplitude in slow waves similar to the effect of other benign obstruction.