Risk factors for the gastric cardia cancer: a case-control study in Fujian Province

AIM: The incidence of gastric cardia cancer has greatlyincreased in the past 2-3 decades, however, the risk factorsfor the disease are still not clearly understood. Theinvestigations among Chinese population on the risk factorsof gastric cardia cancer were also scarcely reported. Wetherefore conducted a case-control study in Fujian province,China, to investigate the potential risk and protective factorsof this disease.METHODS: 191 cardia and 190 non-cardia gastric cancercases, and a total of 222 control cases were included in thisstudy. Standard questionnaires were used in collectingepidemiological factors and the data were then analyzed bythe unconditional logistic regression model.RESULTS: As the factors such as age, gender, smoking,alcohol consumption, and family history of gastric cancerwere controlled, a multivariable analysis was conducted,which revealed that there was a significant correlationbetween the dietary habits such as irregular meal, over andfast eating, and the gastric cardia cancer with the odds ratios(ORs) of 4.2 (95 % confidence interval: 2.3-7.7), 4.7 (2.1-10.8), and 2.7 (1.3-5.3) respectively. Other correlations werealso observed between the gastric cardia cancer and theconsumption of salty fish or pickled vegetable, smoking,and the family cancer history with the ORs of 5.5 (1.4-19.5),1.8 (1.0-3.0), 2.1 (1.3-3.5), and 3.8 (2.3-6.2) respectively.In contrast, the negative correlations were found existingbetween the intake of fresh vegetables and fruits, the useof refrigerator, and the gastric cardia cancer, with the ORsof 0.4 (0.2-0.9), 0.2 (0.1-0.5), and 0.2 (0.1-0.4),respectively. However, dietary habits were associated lesswith non-cardia gastric cancer compared with its cardiacounterpart.CONCLUSION: Dietary habits might be one of the riskfactors for the cardia carcinogenesis among Chinesepopulation.

Cytochrome p450 2E1 polymorphisms and the risk of gastric cardia cancer

AIM: Genetic polymorphisms of drug-metabolizing enzymes have recently been shown to affect susceptibility to chemical carcinogenesis. Cytochrome P450 2E1 (CYP2E1)enzyme catalyzes the metabolism of many procarcinogens,such as N-nitrosamines and related compounds. The gene coding for this enzyme is polymorphic and thus may play a role in gastric cardia cancer (GCC) etiology. In this hospital-based case-control study, we evaluate the relationship between genetic polymorphisms of CYP2E1and the risk of GCC.METHODS: The study subjects comprised 159 histologically confirmed GCC cases identified via hospital cancer registry and surgical records at five hospitals in Fuzhou, Fujian Province, China, between April and November 2001.Controls were 192 patients admitted to the same hospitals for nonmalignant conditions. The genotypes of CYP2E1were detected by a PCR-based RFLP assay. The odds ratios were estimated by logistic regression analyses and were adjusted for potential confounding factors.RESULTS: The distribution of three genotypes of CYP2E1in GCC cases and controls was significantly different (X2 = 16.04, P＜0.01). The frequency of the CYP2E1 (c1/c1)genotype in GCC cases and controls was 60.4% and 40.1%,respectively. The CYP2E1 (c1/c1) genotype was associated with an increased risk for GCC (the adjusted (OR) was 2.37, 95% confidence interval (CI): 1.52-3.70). Subjects who carried the CYP2E 1 (c1/c1) genotype and were habitual smokers were at a significantly higher risk of developing GCC (OR = 4.68, 95%CI: 2.19-10.04) compared with those who had the CYP2E1 (c1/c2or c2/c2') genotype and did not smoke.CONCLUSION: These results suggest that the CYP2E 1genotype may influence individual susceptibility to development of GCC, and that the risk increases significantly in smokers.