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Objectives: In a population-based case–control study in Yangzhong, China, we investigated the relationship between genetic polymorphisms of GSTP1 and susceptibility to gastric cancer and its premalignant lesion, chronic gastritis. The possible gene–gene interactions between GSTP1 polymorphisms and GSTM1, GSTT1 genes were explored. Methods: Epidemiologic data were collected by standard questionnaire from 133 gastric cancer cases, 166 chronic gastritis cases, and 433 cancer-free population controls. Blood samples for Helicobacter pylori and molecular marker assays were collected from 84 gastric cancer cases, 146 chronic gastritis, and 429 population controls. GSTP1 polymorphisms were determined by the PCR-RFLP method and H. pylori infection was measured by the ELISA method. Associations between certain GSTP1 genotypes and both gastric cancer and chronic gastritis were assessed by odds ratios (ORs) and 95% confidence intervals (CIs) derived from logistic regression. Results: The distributions of three GSTP1 genotypes, Ile/Ile, Ile/Val, and Val/Val, were similar in gastric cancer cases, chronic gastritis, and controls. After adjusting for age, gender, education, body mass index, pack-year of smoking, alcohol drinking, H. pylori infection, salt and fruit intakes, the adjusted ORs of Val/Val were 1.3 (95% CI: 0.1–11.2) for gastric cancer and 0.9 (95% CI: 0.2–4.8) for chronic gastritis. Combining the Val alleles (Val/Val and Ile/Val) into one group, no association was observed between GSTP1 and both gastric cancer and chronic gastritis. In addition, the allelism at the GSTP1 locus did not increase gastric cancer and chronic gastritis risks associated with the GSTM1 or GSTT1 genotypes. Conclusion: Our data suggest that the GSTP1 genotype seems not to be associated with the risk of gastric cancer and chronic gastritis in a high-risk Chinese population.

Background A pathway-based genotyping analysis suggested rs2078486 was a novel TP53 SNP, but very few studies replicate this association. TP53 rs1042522 is the most commonly studied SNP, but very few studies examined its potential interaction with environmental factors in relation to lung cancer risk. This study aims to examine associations between two TP53 single-nucleotide polymorphisms (SNPs) (rs2078486, rs1042522), their potential interaction with environmental factors and risk of lung cancer. Methods A case–control study was conducted in Taiyuan, China. Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs). Multiplicative and additive interactions between TP53 SNPs and lifestyle factors were evaluated. Results Variant TP53 rs2078486 SNP was significantly associated with elevated lung cancer risk among smokers (OR: 1.70, 95% CI: 1.08 - 2.67) and individuals with high indoor air pollution exposure (OR: 1.51, 95% CI: 1.00-2.30). Significant or borderline significant multiplicative and additive interactions were found between TP53 rs2078486 polymorphism with smoking and indoor air pollution exposure. The variant genotype of TP53 SNP rs1042522 significantly increased lung cancer risk in the total population (OR: 1.57, 95% CI: 1.11-2.21), but there was no evidence of heterogeneity among individuals with different lifestyle factors. Conclusions This study confirmed that TP53 rs2078486 SNP is potentially a novel TP53 SNP that may affect lung cancer risk. Our study also suggested potential synergetic effects of TP53 rs2078486 SNP with smoking and indoor air pollution exposure on lung cancer risk.

The effect of drinking Chinese green tea on the risk of stomach cancer was evaluated in a population-based case-control study conducted in Shanghai, China, from October 1991 to December 1993. Eligible cases were incident cases of primary stomach cancer diagnosed during the study period among residents of Hongkou district and Nanhui county aged under 80 years. Controls were selected from the same street or commune where the case resided and were matched to the cases on age (within three years) and gender. A total of 711 cases and 711 matched controls, more than 90 percent of the eligible subjects, completed the interview. Information was obtained on the types of tea used, age when habitual tea drinking started, frequency of new batches of tea leaves used per day, number of cups brewed from each batch, total duration of drinking for each batch, strength and temperature of the tea consumed. Statistical analysis was based on modelling through conditional logistic regression. After adjusting for age, gender, place of residence, education, birthplace, alcohol consumption, and cigarette smoking, the odds ratio (OR) comparing drinkers of green tea with nondrinkers was 0.71 (95 percent confidence interval = 0.54-0.93). The adjusted OR decreased with increasing number of new batches of the green tea consumed each day (P value trend = 0.006). With the largest series of stomach cancer cases to date, this study found green-tea consumption associated with lower risk of stomach cancer. Among drinkers of green tea, the risk of stomach cancer did not depend on the age when habitual green-tea drinking started. Green tea may disrupt gastric carcinogenesis at both the intermediate and the late stages.