Serological Immunoglobulin G Antibody Titers to Helicobacter pylori in Japanese Brazilian and Non-Japanese Brazilian Gastric Cancer Patients and Controls in Sao Paulo

Helicobacter pylori (II. pylori) infection is considered a cause of gastric cancer (GC), though evidence for this association is scarce in high-risk areas. Possible case control and/or ethnic differences were investigated as to the presence of H. pylori and its immunogoblin G antibody tiler in the multi-ethnic city of Sao Paulo. where the incidence of GC is relatively high. We performed a cross-sectional comparison of antihody titers to H pylori in Japanese Brazilian, and non-Japanese Brazilian GC patients and their controls. Japanese Brazilian patients were matched by age. sex and ethnicity with two controls, while non-Japanese Brazilian patients were matched as above with one control. Among Japanese Brazilians 59 of 93 (63.4%) patients with GC and 127 of 186 (68.3%) controls were positive for H. pylori-specific antibody (odds ratio (OR)=0.80. 95% , confidence Interval (CI) =0.47-1.36), while among non-Japanese Brazilians, 171 of 228 patients with GC (75.7%) and 178 of 226 controls (78.8%) were positive (OR =0.84, 95% CI=0.54-1.30). The median serum antibody titer was lower in cases than in controls in both ethnic groups. A high titer (H pylori titer >50) was associated with less likelihood of (IC for both ethnic groups (for Japanese Brazilians. OR=0.39. 95%CI=0.16-0.92: for non-Japanese Brazilians. OR=036. 95%C1=031-1.02). The high titer can he regarded as a sign of the necessity of eradication, and low titer is regarded as a sign of the necessity of close screening for GC in both ethnic groups, because extended atrophy may cause spontaneous disappearance of H. pylori from the stomach