Differences in Helicobacter pylori and CagA antibody changes after eradication between subjects developing and not developing gastric cancer

Abstract

We evaluated serological Helicobacter pylori and cytotoxin associated gene A (CagA) antibodies and endoscopic atrophy after eradication to identify factors predicting posteradication gastric cancer development. Thirtyfive patients with successful eradiation were divided into the posteradication gastric cancer (13 cases) and nongastric cancer (22 cases) groups. Serum Helicobacter pylori and CagA antibody titers and endoscopic atrophy before and six years after eradication were examined. Median Helicobacter pylori antibody titers had decreased significantly from baseline at 0.5–2 years after eradication in both groups (gastric cancer group, from 39.0 to 11.0 U/ml, p = 0.011; nongastric cancer group, from 29.6 to 4.97 U/ml, p<0.001), but were significantly higher in the gastric cancer than in the nongastric cancer group (p = 0.029). Median serum CagA antibody titers had also decreased signifi cantly at 0.5–2 years after eradication (gastric cancer group, from 6.35 to 3.23 U/ml, p = 0.028; nongastric cancer group, from 9.88 to 1.21 U/ml, p = 0.0045). Serum CagA in each group showed no significance. Endoscopic atrophy improved significantly after eradication in the nongastric cancer, but not the gastric cancer, group (p = 0.0007). In conclusion, changes in Helicobacter pylori and CagA antibody titers and endoscopic atrophy after eradication might be useful as predictive factors for posteradication gastric cancer.