A case-control study on the relationship between methyl-tetra-hydrofolic acid reductase 677 gene polymorphism and the risk of stomach cancer / 中华流行病学杂志

<p><b>OBJECTIVE</b>To explore the relationship between methyl-tetra-hydrofolic acid (MTHFR) 677 gene polymorphism and the risk of stomach cancer.</p><p><b>METHODS</b>A population based case-control study was conducted and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used to detect its genotypes.</p><p><b>RESULTS</b>Among cases with stomach cancer, the frequency of C/C, C/T, T/T genotype were 25.8%, 54.6%, 19.6%, compared with controls as 34.5%, 50.9%, 14.6% respectively. Using C/C genotype as reference, the OR of C/T or T/T genotype was 1.52 (95% CI: 1.04 - 2.23). 53.3% C and 46.7% T allele were distributed in stomach cancer cases, while 60.0% C and 40.0% T in controls. The OR for T allele in relation to C allele was 1.31 (1.02 - 1.69) when C allele was used as reference. In addition, the present study showed that MTHFR677 AnyT genotype might interact with smoking, moldy food intake, wheat porridge intake, eating salty food and Hp CagA infection to increase the risk of stomach cancer. No interaction was observed between MTHFR677 AnyT genotype and alcohol drinking or green tea intake.</p><p><b>CONCLUSION</b>MTHFR677 AnyT genotype, might increase the risk of stomach cancer development and the genotype might also interact with other environmental risk factors to increase the risk of stomach cancer.</p>

A case-control study on drinking green tea and decreasing risk of cancers in the alimentary canal among cigarette smokers and alcohol drinkers / 中华流行病学杂志

<p><b>OBJECTIVE</b>To explore the role of green tea in decreasing the risks of gastric cancer, liver cancer, esophageal cancer among alcohol drinkers or cigarette smokers.</p><p><b>METHODS</b>A population based case-control study was conducted in Taixing, Jiangsu province.</p><p><b>RESULTS</b>In Taixing city, identified cases of stomach, liver and esophageal cancers were chosen with informed consent. The numbers were 206, 204, 218 respectively. Controls were chosen from normal population having lived in the area for longer than 10 years, also with informed consent. Green tea drinking seemed to have decreased 81%, 78%, 39% risk for the development of gastric cancer, liver cancer and esophageal cancer among alcohol drinkers. It might also have decreased 16%, 43%, 31% on the risks of developing the three kinds of cancers among cigarette smokers. Interaction assessment showed that drinking green tea could significantly decrease the risk of gastric cancer and liver cancer among alcohol drinkers, with ORs of interaction item 0.23 (95% CI: 0.10 - 0.55) and 0.25 (95% CI: 0.11 - 0.57) respectively.</p><p><b>CONCLUSION</b>Habit of drinking green tea seemed to have significant protective effects on the development of both gastric and liver cancer among alcohol drinkers while, green tea also having some protective effect on esophageal cancer among alcohol drinkers and on three kinds of cancers among cigarette smokers.</p>