Objective: To conduct a comprehensive quantitative analysis about the association between genetic polymorphisms of CYP 2E1 and susceptibility to Chinese gastric cancer in order to offer evidence-based evidence for the etiology of gastric cancer.
Methods: Using the keywords and entry terms of cytochrom P450 2E1, cytochrome P450, CYP 2E1, stomach neoplasms, individual susceptibility, gene polymorphism, risk factors in English and Chinese, we searched medical literature databases, such as Pub Med, Embase, CBM, VIP, CNKI, China Info, published from January 1 th, 1997 to December 31 th, 2016, the Chines population was selected as the research object. Metaanalysis was performed using Stata 14. 0 in literature that selected quality studies of original literatures of more than 6 stars.
Results: There were 10 high-quality original articles covering high, middle and low incidence areas of gastric cancer in our country, with 832 cases and 1018 controls were included, which fit the HWE test. The population with CYP 2E1 C1C2 genotype have a lower risk of developing gastric cancer than the population with CYP 2E1 C1C1 genotype( OR = 0. 650, P < 0. 001, 95% CI 0. 515-0. 821); Subgroup-analysis result reveals that, in smaller sample size population with CYP 2E1 C1C1 genotype have a gastric cancer risk of 2. 02 times the risk of having gastric cancer with CYP 2E1 C1C2 and C2C2 genotypes( P < 0. 001, 95% CI 1. 55-2. 64), in bigger sample size population with CYP 2E1 C1C1 genotype have a gastric cancer risk of0. 93 times the risk of having gastric cancer with CYP 2E1 C1C2 and C2C2 genotypes( P = 0. 586, 95% CI 0. 71-1. 22), in overall sample size population with CYP 2E1 C1C1 genotype have a gastric cancer risk of 1. 50 times the risk of having gastric cancer with CYP 2E1 C1C2 and C2C2 genotypes( P = 0. 006, 95% CI 1. 12-2. 00).
Conclusion: The size of the sample is an important factor affecting the result. The small sample size of the study tends to get positive result. Whether CYP 2E1 C1C1 genotype of the population is a risk factor for gastric cancer remains to be further studied.
Keywords: Meta-analysis; cytochrome P450 2E1; genetic polymorphism; individual/gegetic susceptibility; risk factors; stomach neoplasms.