Frequency of Helicobacter pylori and CagA antibody in patients with gastric neoplasms and controls: The Indian enigma

Background: Despite association between H. pylori and gastric neoplasm (GN) from the developed world, studies from India, where infection is more common and acquired early, are scant and contradictory. Methods: Two hundred and seventy-nine patients with GN from two northern and one eastern Indian centers during the period 1997-2005, 101 non-ulcer dyspepsia (NUD), and 355 healthy volunteers (HV) were evaluated for H. pylori [rapid urease test (RUT), histology and anti-H. pylori, and CagA IgG serology]. Results: Patients with GN [263 gastric carcinoma and 16 (6%) primary gastric lymphoma, 208 male] were older than HV (n = 355, 188 male) and NUD (n = 101, 54 male) patients (53 ± 12 versus 44 ± 17 and 43 ± 13 years, respectively; P < 0.001). Eastern Indian patients with GN (n = 145) were younger than those from northern India (n = 134; 52 ± 12 versus 55 ± 12 years; P < 0.007, t-test). In GN and NUD patients H. pylori positivity by RUT [86/225 (38%) versus 46/101 (46%)], anti-H. pylori IgG [154/198 (78%) versus 85/101 (84%)], and histology [136/213 (64%) versus 55/101 (55%)] were comparable (χ ²-test). Serum IgG anti-H. pylori antibody was more common among HV than among GN patients [300/355 (85%) versus 154/198 (78%); P = 0.04, χ ²-test]. Intestinal metaplasia was more common in GN than in NUD patients [101/252 (40%) versus 2/98 (2%), P < 0.000, χ ²-test]. CagAIgG was more common in GN than in NUD patients [124/163 (76%) versus 64/101 (63%)] but comparable to that in HV patients [87/98 (89%), P = NS]. Conclusion: Frequency of H. pylori as detected using endoscopy and serology-based tests is not higher among patients with GN as compared with controls in India.