-765G > C COX-2 polymorphism may be a susceptibility marker for gastric adenocarcinoma in patients with atrophy or intestinal metaplasia

AIM： To investigate the relationship between the -765G 〉 C COX-2 polymorphism and the development of different gastric lesions： atrophy or intestinal metaplasia and gastric adenocarcinoma. METHODS： A cross-sectional study was performed involving 320 Portuguese individuals （210 without evidence of neoplastic disease, 73 patients with gastric adenocarcinomas and 37 with atrophy or intestinal metaplasia） using a PCR-RFLP method.RESULTS： -765C allele was overrepresented in the patients with gastric adenocarcinoma （51%） when compared either with the control group （38%） or patients with atrophy or intestinal metaplasia （27%）. Callele was found to be very common in our population （0.22）, and a multivariate logistic regression analysis revealed nearly 3-fold increased risk for the progression to gastric adenocarcinoma in patients with atrophy or intestinal metaplasia carrying the -765C allele （OR = 2.67, 95% CI = 1.03-6.93; P = 0.04）.CONCLUSION： -765C carrier status should be considered as another susceptibility marker for gastric adenocarcinoma development in patients with atrophy or intestinal metaplasia.

Gastric cancer in a Caucasian population: Role of pepsinogen C genetic variants

AIM： To study the role of an insertion/deletion polymorphism in the pepsinogen C （PGC） gene, an effective marker for terminal differentiation of the stomach mucosa, in the susceptibility to the development of gastric lesions. METHODS： The study was performed with 99 samples of known gastric lesions and 127 samples without evidence of neoplastic disease. PCR was employed and the 6 polymorphic alleles were amplified： Allele 1 （510 bp）, Allele 2 （480 bp）, Allele 3/4 （450/460 bp）, Allele 5 （400 bp） and Allele 6 （310 bp）. RESULTS： Our results revealed that Allele 6 carriers seemed to have protection against the development of any gastric lesion （OR = 0.34; P 〈 0.001）, non-dysplastic lesions associated with gastric adenocarcinoma such as atrophy or intestinal metaplasia （OR = 0.28; P 〈 0.001） or invasive GC （OR = 0.39; P = 0.004）. CONCLUSION： Our study reveals that the Allele 6 carrier status has a protective role in the development of gastric lesions, probably due to its association with higher expression of PGC. Moreover, the frequency of Allele 6 carriers in the control group is far higher than that obtained in Asian populations, which might represent a genetic gap between Caucasian and Asian populations.