H pylori status and angiogenesis factors in human gastric carcinoma

AIM： To investigate H pylori expression in gastric cancer patients in relation to primary tumor angiogenic markers, such as microvessel density （MVD）, thymidine phosphorylase （TP）, vascular endothelial growth factor receptor-1 （VEGF-R1）, p53 and circulating VEGF levels. METHODS： Angiogenic markers were analyzed immunohistochemically in 56 primary gastric cancers. H pylori cytotoxin （vacA） and the cytotoxin-associated gene （cagA） amplification were evaluated using PCR assay. Serum H pylori IgG antibodies and serum/plasma circulating VEGF levels were detected in 39 and 38 patients by ELISA, respectively. RESULTS： A total of 69% of patients were positive for circulating IgG antibodies against Hpylori. cagA-positive H pylor/strains were found in 41% of gastric patients. vacA was found in 50% of patients; s1 strains were more highly expressed among vacA-positive patients. The presence of the s1 strain was significantly associated with cagA （P = 0.0001）. MVD was significantly correlated with both tumor VEGF expression （r = 0.361, P = 0.009） and serum VEGF levels （r = -0.347, P = 0.041）.Conversely, neither VEGF-R1 expression nor MVD was related to p53 expression. However, H pylori was not related to any angiogenic markers except for the plasma VEGF level （P = 0.026）. CONCLUSION： H pylori antigen is related to higher plasma VEGF levels, but not to angiogenic characteristics. It can be hypothesized that the toxic effects of H pylori on angiogenesis occurs in early preclinical disease phase or in long-lasting aggressive infections, but only when high H pylori IgG levels are persistent.