Junko Ueda

Comparative epidemiology of gastric cancer between Japan and China.

AIM To clarify the similarities and differences in gastric cancer epidemiology between Japan and China. METHODS A comprehensive literature search of the PubMed database was performed. The relevant literature published in China was also been cited. Data on incidence and mortality rates in 2008 were obtained from the Cancer Mondial database, published by International Agency for Research on Cancer at http://www-dep.iarc.fr/. RESULTS Gastric cancer remains a significant public health burden in both Japan and China. The prevalence of Helicobacter pylori (H. pylori) colonization is high in the adult populations of both countries. Accumulating evidence from intervention studies in both countries has shown the effectiveness of H. pylori eradication in reducing gastric cancer incidence. There are differences, however, in many aspects of gastric cancer, including patterns of incidence and mortality, trends in the prevalence of H. pylori infection, H. pylori strains, the magnitude of risk of gastric cancer related to H. pylori infection, and associations with dietary habits. Compared with China, Japan has seen a more rapid decline in H. pylori infection among adolescents. While Japanese cohort studies have dominated the literature concerning the associations between gastric cancer and dietary habits, numerous case-control studies in China suggest a positive association between a high intake of preserved fish and vegetables and gastric cancer risk. There is a need for a multidisciplinary research approach to understand the interactions between various strains of H. pylori, host factors, and other lifestyle and environmental factors in gastric carcinogenesis in both countries. CONCLUSION The shared high incidence of gastric cancer and high prevalence of H. pylori, as well as differences in many aspects of gastric cancer, provide an excellent opportunity to establish Sino-Japanese collaborations.

Prevalence of Helicobacter pylori Infection by Birth Year and Geographic Area in Japan

Helicobacter pylori (H. pylori)‐related diseases are responsible for a tremendous amount of morbidity and mortality in Japan. We estimated the prevalence of H. pylori infection by sex, birth year, and geographic area among Japanese adults.

Diagnostic Accuracy of the E-Plate Serum Antibody Test Kit in Detecting Helicobacter pylori Infection Among Japanese Children

Background A number of noninvasive diagnostic tests are available to detect Helicobacter pylori infection. Data on serologic testing of children are lacking, however, and thus it remains unclear whether the serology cutoff points used for adults are appropriate for children. Methods Serum and stool samples were obtained from 73 children who visited 5 hospitals in Japan between March 1993 and December 2009. Analysis of stool samples was carried out using an H pylori stool antigen enzyme-linked immunosorbent assay (HpSA ELISA), and serum antibodies to H pylori were examined using an antibody determination kit (E-Plate Eiken H pylori antibody). The validity of the serologic test was evaluated based on its sensitivity, specificity, and receiver operating characteristics curve. Results Of the 73 children included in this study, 34 were HpSA-positive and 39 were negative. Among the 34 HpSA-positive patients, 32 were IgG-positive and 2 were IgG-negative. Of the 39 patients who were HpSA-negative, 38 were IgG-negative and 1 was IgG-positive. The sensitivity, specificity, and positive likelihood ratio for IgG antibody testing were 91.2%, 97.4%, and 35.6, respectively, based on the recommended adult cutoff point of 10 U/ml. Among children, use of cutoff points in the range of 7 to 9 U/ml yielded optimal values for sensitivity and specificity, as well as a positive likelihood ratio. Conclusions The performance of the E-plate anti-H pylori IgG antibody test was comparable to that of the stool antigen test and is therefore suitable for epidemiologic studies of H pylori infection in large samples.

Association between variations in the fat mass and obesity-associated gene and pancreatic cancer risk: a case-control study in Japan

BackgroundIt is clear that genetic variations in the fat mass and obesity-associated (FTO) gene affect body mass index and the risk of obesity. Given the mounting evidence showing a positive association between obesity and pancreatic cancer, this study aimed to investigate the relation between variants in the FTO gene, obesity and pancreatic cancer risk.MethodsWe conducted a hospital-based case–control study in Japan to investigate whether genetic variations in the FTO gene were associated with pancreatic cancer risk. We genotyped rs9939609 in the FTO gene of 360 cases and 400 control subjects. An unconditional logistic model was used to estimate the odds ratio (OR) and 95% confidence interval (CI) for the association between rs9939609 and pancreatic cancer risk.ResultsThe minor allele frequency of rs9939609 was 0.18 among control subjects. BMI was not associated with pancreatic cancer risk. Compared with individuals with the common homozygous TT genotype, those with the heterozygous TA genotype and the minor homozygous AA genotype had a 48% (OR=1.48; 95%CI: 1.07–2.04), and 66% increased risk (OR=1.66; 95%CI: 0.70–3.90), respectively, of pancreatic cancer after adjustment for sex, age, body mass index, cigarette smoking and history of diabetes. The per-allele OR was 1.41 (95%CI: 1.07–1.85). There were no significant interactions between TA/AA genotypes and body mass index.ConclusionsOur findings indicate that rs9939609 in the FTO gene is associated with pancreatic cancer risk in Japanese subjects, possibly through a mechanism that is independent of obesity. Further investigation and replication of our results is required in other independent samples.

Multilocus sequence typing of DNA from faecal specimens for the analysis of intra-familial transmission of Helicobacter pylori

This study used multilocus sequence typing (MLST) of total DNA extracted from faecal specimens to genotype Helicobacter pylori to analyse intra-familial transmission. Faecal DNA was extracted and amplified by nested PCR. The products were analysed by direct sequencing and the allele type was determined using an MLST website. Mother-to-child transmission was suspected in at least two of three families, and father-to-child transmission was suspected in one family.

Reduced serum vascular endothelial growth factor receptor‐2 (sVEGFR‐2) and sVEGFR‐1 levels in gastric cancer patients

The relationship between gastric cancer and serum vascular endothelial growth factor receptor‐1 (sVEGFR‐1) and sVEGFR‐2, which are soluble form receptor proteins of vascular endothelial growth factor (VEGF), has not been extensively studied. VEGF, sVEGFR‐1 and sVEGFR‐2 were measured in the sera obtained before surgical operation from 164 gastric cancer patients and from 164 healthy controls matched for age and gender. Compared with controls, the cases showed elevated VEGF (P < 0.01) and reduced sVEGFR‐1 (P = 0.07) and sVEGFR‐2 (P = 0.02). The difference in VEGF levels was small among men and when the outcome was early cancer. The difference in sVEGFR‐1 levels was significant or borderline significant only in men and when the outcome was diffuse type cancer. The difference in sVEGFR‐2 levels was significant only in men and when the outcome was advanced or diffuse type cancer. The sensitivities and specificities of VEGF, sVEGFR‐1 and sVEGFR‐2 were all approximately 60%. For diffuse type cancer, sVEGFR‐2 showed a sensitivity of 62.4% and a specificity of 63.4%, which was similar to serum pepsinogen. In conclusion, elevated VEGF and reduced sVEGFR‐1 and sVEGFR‐2 in serum are characteristic of gastric cancer patients, and the value of serum sVEGFR‐2 in the diagnosis of diffuse type gastric cancer should be further evaluated. (Cancer Sci 2011; 102: 866–869)

Evaluation of a stool antigen test using a mAb for native catalase for diagnosis of Helicobacter pylori infection in children and adults.

Non-invasive diagnosis of Helicobacter pylori infection is important not only for screening of infection but also for epidemiological studies. Stool antigen tests are non-invasive and are convenient to identify H. pylori infection, particularly in children. We evaluated the stool antigen test, which uses a mAb for native catalase of H. pylori developed in Japan. A total of 151 stool samples were collected from participants (52 children and 99 adults) of the Sasayama Cohort Study and stored between -30 and -80 °C. The stool antigen test used was Testmate pylori antigen (TPAg), and was performed according to the manufacturers instructions. Furthermore, we conducted a quantitative real-time PCR test and compared the PCR results with those of the TPAg test. When compared with the results in real-time PCR, the sensitivity of TPAg was 89.5 % overall, 82.7 % for children and 92.4 % for adults, and the specificity was 100 %. The accuracy was 93.4 % overall, 90.4 % for children and 94.9 % for adults, and there was no significant difference in the accuracy of TPAg between children and adults. Five of 28 children (18 %) and five of 38 adults (13 %) were PCR positive with negative TPAg results. Four of five children with positive PCR and negative TPAg results were given a (13)C-urea breath test and all four children tested negative. No significant correlation was observed between the TPAg results and DNA numbers of H. pylori in faeces among children or adults. A stool antigen test (TPAg) using a mAb for native catalase is useful for diagnosis of H. pylori in children and adults. Additionally, this test has particularly high specificity.

Active and passive smoking and risk of death from pancreatic cancer: Findings from the Japan Collaborative Cohort Study

BACKGROUND There is uncertainty in the risk of pancreatic cancer with particular aspects of smoking, such as a dose-response relationship and cumulative amount, in Japanese men and women. Very few studies have addressed the role of passive smoking in pancreatic cancer among Japanese women. METHODS We examined the association between active or passive smoking and the risk of death from pancreatic cancer using data from the Japan Collaborative Cohort Study. The cohort participants (46,395 men and 64,190 women) were followed-up for mortality from baseline (1988-1990) through December 31, 2009. Cox proportional hazards regression models were used to estimate relative risks (RR) and 95% confidence intervals (CI). RESULTS During follow-up, we recorded 611 pancreatic cancer deaths. After adjustment for potential confounding factors, current smokers had a significantly increased risk of death from pancreatic cancer compared with non-smokers, with an RR of 1.70 (95% CI: 1.33-2.19). The risk of death from pancreatic cancer significantly increased with increasing numbers of cigarettes smoked per day. Exposure to environmental tobacco smoke (ETS) in public spaces was not associated with risk of death from pancreatic cancer. The RR for women who reported ETS exposure was 1.20 (95% CI: 0.87-1.67). Women exposed to ETS during childhood or adolescence had 1.21-fold increased risk, but the association was statistically insignificant. CONCLUSIONS Cigarette smoking is associated with an approximately 70% increase in the risk of death from pancreatic cancer. Further studies with improved exposure assessment are needed to better quantify the association between passive smoking and pancreatic cancer.

Case-control study of diabetes-related genetic variants and pancreatic cancer risk in Japan

AIM To examine whether diabetes-related genetic variants are associated with pancreatic cancer risk. METHODS We genotyped 7 single-nucleotide polymorphisms (SNPs) in PPARG2 (rs1801282), ADIPOQ (rs1501299), ADRB3 (rs4994), KCNQ1 (rs2237895), KCNJ11 (rs5219), TCF7L2 (rs7903146), and CDKAL1 (rs2206734), and examined their associations with pancreatic cancer risk in a multi-institute case-control study including 360 cases and 400 controls in Japan. A self-administered questionnaire was used to collect detailed information on lifestyle factors. Genotyping was performed using Fluidigm SNPtype assays. Unconditional logistic regression methods were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between these diabetes-associated variants and pancreatic cancer risk. RESULTS With the exception of rs1501299 in the ADIPOQ gene (P = 0.09), no apparent differences in genotype frequencies were observed between cases and controls. Rs1501299 in the ADPIOQ gene was positively associated with pancreatic cancer risk; compared with individuals with the AA genotype, the age- and sex-adjusted OR was 1.79 (95%CI: 0.98-3.25) among those with the AC genotype and 1.86 (95%CI: 1.03-3.38) among those with the CC genotype. The ORs remained similar after additional adjustment for body mass index and cigarette smoking. In contrast, rs2237895 in the KCNQ1 gene was inversely related to pancreatic cancer risk, with a multivariable-adjusted OR of 0.62 (0.37-1.04) among individuals with the CC genotype compared with the AA genotype. No significant associations were noted for other 5 SNPs. CONCLUSION Our case-control study indicates that rs1501299 in the ADIPOQ gene may be associated with pancreatic cancer risk. These findings should be replicated in additional studies.

1026 Prevalence of Helicobacter pylori Infection in Children and “Test and Treat” to Junior High School Students: Strategies for Extermination of Gastric Cancer in Japan

Table 1. Values are odds ratios (95% confidence interval) from logistic regression models. N represents total number of subjects. *p < 0.05. Models were adjusted for maternal educational level, history of asthma and atopy, smoking during pregnancy, and parity, and for childs gender, ethnicity, gestational age at birth, birth weight, breastfeeding habits, day care attendance, pet keeping, and lower respiratory tract infections.