Endoscopic Determination of the Extent of Early Ulcerated Gastric Cancer by the Congo Red Test

The accuracy of the endoscopic Congo red test in the establishment of the extension of gastric cancer was determined in 35 patients with ulcerated early cancer. This test increased the diagnostic rate to 85.7 % from the rate of 40 % by routine endoscopy alone. In this test, the circumference of the oral side of the ulcerated tumors was observed as a “non-discolored” area surrounded by, or adjacent to, an acid-secreting area.