An association between CYP1A1 polymorphisms and lung selleck chemicals cancer was first reported by Kawajiri and co-workers in 1990 among an Asian study population (Febs Lett 1990;263:131-133)[9], after which many studies analyzed the influence of CYP1A1 polymorphisms on lung cancer risk; no clear consensus, however, click here was reached. Moreover, 3 meta-analyses have reported conflicting results. Houlston RS [10] found no statistically significant association between
the MspI polymorphism and lung cancer risk in 2000, in a meta-analysis performed by Le Marchand L et al. [11] included only 11 studies, the exon 7 polymorphism did not correlate with lung cancer risk. Shi × [12], however, noted a greater risk of lung cancer for CYP1A1 MspI and exon 7 polymorphism carriers in a meta-analysis that included only Chinese population. A single study might not be powered sufficiently to detect a small effect of the polymorphisms on lung cancer, particularly in relatively small sample sizes. Various types of study populations and study designs might also have contributed to these disparate findings. To clarify the effect of the CYP1A1 polymorphism
on the risk for lung cancer, this website we performed an updated meta-analysis of all eligible case-control studies to date and conducted the subgroup analysis by stratification according to the ethnicity source, histological types of lung caner, gender and smoking status of case and control population. 2. Materials and methods 2.1 Publication search We searched for studies in the PubMed, Embase, Web of Science, and CNKI (China National Knowledge Infrastructure) electronic databases to include in this meta-analysis, using the terms “”CYP1A1,”" “”Cytochrome P450 1A1,”" “”polymorphism,”" and “”lung cancer.”" An upper date limit of June, 2010 was applied; no lower date limit was used. The search was performed without any restrictions on language and was focused on studies that had been conducted in humans. We also
reviewed the Cochrane Library for relevant articles. Concurrently, Megestrol Acetate the reference lists of reviews and retrieved articles were searched manually. When the same patient population appeared in several publications, only the most recent or complete study was included in this meta-analysis. 2.2 Inclusion criteria For inclusion, the studies must have met the following criteria: they (1) evaluated CYP1A1 gene polymorphisms and lung cancer risk; (2) were case-control studies or nested-case control study; (3) supplied the number of individual genotypes for the CYP1A1 MspI and exon 7 polymorphisms in lung cancer cases and controls, respectively; and (4) demonstrated that the distribution of genotypes among controls were in Hardy-Weinberg equilibrium. 2.3 Data extraction Information was extracted carefully from all eligible publications independently by 2 authors, based on the inclusion criteria above.