Gastric cancer is classified into intestinal and diffuse types, the latter including a highly malignant form, linitis plastica. A two-stage genome-wide association study (stage 1: 85,576 SNPs on 188 cases and 752 references; stage 2: 2,753 SNPs on 749 cases and 750 controls) in Japan identified a significant association between an intronic SNP (rs2976392) in PSCA (prostate stem cell antigen) and diffuse-type gastric cancer (allele-specific odds ratio (OR) = 1.62, 95% CI = 1.38-1.89, P = 1.11 x 10(-9)). The association was far less significant in intestinal-type gastric cancer. We found that PSCA is expressed in differentiating gastric epithelial cells, has a cell-proliferation inhibition activity in vitro and is frequently silenced in gastric cancer. Substitution of the C allele with the risk allele T at a SNP in the first exon (rs2294008, which has r(2) = 0.995, D' = 0.999 with rs2976392) reduces transcriptional activity of an upstream fragment of the gene. The same risk allele was also significantly associated with diffuse-type gastric cancer in 457 cases and 390 controls in Korea (allele-specific OR = 1.90, 95% CI = 1.56-2.33, P = 8.01 x 10(-11)). The polymorphism of the PSCA gene, which is possibly involved in regulating gastric epithelial-cell proliferation, influences susceptibility to diffuse-type gastric cancer.

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The IL-1 beta-511 genetic polymorphism was not associated with gastric cancer in a multistep carcinogenesis model. However, in view of the results for the IM or CAG without H. pylori group, the presence of the C allele may also indicate a risk of mucosal atrophy of the stomach in the Japanese population.

A clinical pathway for gastrectomy patients proved useful to optimize their postoperative care, including medication management and diet education. It is suggested that the implementation of a standardized clinical pathway for gastrectomy patients reduced the length of the hospital stay and the medical costs.

We used Helicobacter pylori sero-positivity and mucosal atrophy as detected by the serum pepsinogen method to identify H. pylori infection-negative gastric cancer patients with or without atrophy. One hundred and six of 748 (14.2%) primary gastric cancer patients were infection-negative by a serum antibody detection system. Further, 121 (16.2%) of the 748 were negative for gastric mucosal atrophy by the pepsinogen method, of whom 15/748 (2.0%) were H. pylori-negative by pepsinogen I level (> > > >70 ng/mL) and pepsinogen I/II ratio (> > > >3.0). Twenty-seven of 782 (3.6%) gastric cancer patients were H. pylori-negative by antibodies and severe atrophy as determined by pepsinogen I level (< < < <30 ng/mL) and pepsinogen I/II ratio (< < < <2.0). H. pylori-negative gastric cancer patients with severe atrophy likely had a previous infection. These results indicate that the actual number of H. pylori-negative patients is 2.0% at minimum and 10.6% (14.2% minus 3.6%) at maximum in the general Japanese population. Five of 15 (33%) cases displaying neither anti-H. pylori antibodies nor atrophy were intestinal-type and 10 (67%) were diffuse-type adenocarcinomas. Thirteen surgical patients with primary gastric cancer displaying neither antibodies nor mucosal atrophy were further analyzed for pathological and phenotypic characteristics. The mucin phenotype was divided into four gastric, five gastric and intestinal, two intestinal and two null types, independent of histological classification. Intestinal phenotype elements were detected by Cdx2 immunohistochemical methods in nine of 13 (70%) cases examined. We conclude that a small fraction of gastric cancer patients displayed multifactorial carcinogenesis without H. pylori infection, indicating that gastric cancer risk still exists in the absence of H. pylori infection, at an incidence of 2.0% at minimum and 10.6% at maximum in the general Japanese population. (Cancer Sci 2007; 98: 790-794)T he prevalence of Helicobacter pylori (H. pylori) infection, which varies by ethnicity, location and race, is closely associated with the incidence of gastric cancer. One prospective study found that gastric cancer develops only in patients with H. pylori infection. (1)(2)(3) The gastric mucosa in infected persons is marked by severe atrophic changes associated with intestinal metaplasia. These pathological changes are reported as precursory lesions of gastric cancer, (4) and have raised the possibility of active prevention of the disease. (5,6) However, because H. pylori infection is diminished in severely atrophic mucosa, detection systems for H. pylori infection-negative status have not been fully established. Any conclusive finding of negativity is therefore problematic. Pathological analysis of gastric mucosa after gastrectomy in a series of Japanese patients found that only 2% of gastric cancers occurred in H. pylori-negative patients. (7) Other studies using multiple detection systems including pathological and serological diagnosis similarly found that only 2% of patients with ea...

Triacylglycerol (TG), the main component of edible oil, is oxidized by thermal-or photo-oxidation to form TG hydroperoxide (TGOOH) as the primary oxidation product. Since TGOOH and its subsequent oxidation products cause not only the deterioration of oil quality but also various toxicities, preventing the oxidation of edible oils is essential. Therefore understanding oxidation mechanisms that cause the formation of TGOOH is necessary. Since isomeric information of lipid hydroperoxide provides insights about oil oxidation mechanisms, we focused on dioleoyl-(hydroperoxy octadecadienoyl)-TG (OO-HpODE-TG) isomers, which are the primary oxidation products of the most abundant TG molecular species (dioleoyl-linoleoyl-TG) in canola oil. To secure highly selective and sensitive analysis, authentic OO-HpODE-TG isomer references (i.e., hydroperoxide positional/geometrical isomers) were synthesized and analyzed with HPLC-MS/MS. With the use of the method, photo-or thermal-oxidized edible oils were analyzed. While dioleoyl-(10-hydroperoxy-8E,12Z-octadecadienoyl)-TG (OO-(10-HpODE)-TG) and dioleoyl-(12-hydroperoxy-9Z,13E-octadecadienoyl)-TG (OO-(12-HpODE)-TG) were characteristically detected in photo-oxidized oils, dioleoyl-(9-hydroperoxy-10E,12E-octadecadienoyl)-TG and dioleoyl-(13-hydroperoxy-9E,11E-octadecadienoyl)-TG were found to increase depending on temperature in thermal-oxidized oils. These results prove that our methods not only evaluate oil oxidation in levels that are unquantifiable with peroxide value, but also allows for the determination of oil oxidation mechanisms. From the analysis of marketed canola oils, photooxidized products (i.e., OO-(10-HpODE)-TG and OO-(12-HpODE)-TG) were characteristically accumulated compared to the oil analyzed immediately after production. The method described in this paper is valuable in the understanding of oil and food oxidation mechanisms, and may be applied to the development of preventive methods against food deterioration.

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This study finds that the levels of two different carcinogen-DNA adducts vary in lung tissue (an important target tissue) in association with three separate genetic polymorphisms (i.e., CYP2D6, CYP2E1, and GSTM1). CYP2D6 and CYP2E1 genotypes are associated with higher 7-methyl-dGMP levels, while the GSTM1 null genotype is associated with higher numbers of PAH-dGMP adducts. These findings suggest that genetic polymorphisms are predictive of carcinogen-DNA adduct levels and would thus be predictive of an individual's lifetime response to carcinogen exposure.