OBJECTIVEThis study was designed to investigate the interaction between pepsinogen C(PGC) insertion/deletion polymorphism and Helicobacter pylori(Hp) infection, together with its different subtype strains, in the development of gastric cancer (GC).

METHODSPGC Genotypes were determined by polymerase chain reaction (PCR) assay in 564 subjects with superficial gastritis (NOR), gastric ulcer (GU), atrophic gastritis (AG) and GC, who were frequency-matched as 1:1. Serum Hp-IgG antibodies were determined by an enzyme linked immunoadsorbent assay (ELISA). Hp genetic subtypes in 171 patients with Hp infection were determined by PCR methods.

RESULTSIn GU, AG and GC, the OR of interaction was 8.69 (P = 0.049), 11.16 (P = 0.02), and 10.61 (P = 0.03), respectively; the interaction index of PGC homozygous allele 1 genotype and Hp infection was 5.40, 6.48 or 4.34, respectively; the attributable proportions were 0.721, 0.770 and 0.697, respectively. In AG and GC, no significant interactions were observed between PGC polymorphism and Hp genetic subtypes.

CONCLUSIONThe findings of this study suggest that PGC insertion/deletion polymorphism and Hp infection seem to present a positive interaction in the development of gastric cancer. While no interactions may be present between PGC polymorphism and Hp genetic subtypes.