ABSTRACT
BACKGROUND: Several studies have evaluated the association between polymorphisms of encoding excision repair cross complementation group 1 (ERCC1) enzyme and lung cancer risk in diverse populations but with conflicting results. By pooling the relatively small samples in each study, it is possible to perform a meta-analysis of the evidence by rigorous methods. METHODS: Embase, Ovid, Medline and Chinese National Knowledge Infrastructure were searched. Additional studies were identified from references in original studies or review articles. Articles meeting the inclusion criteria were reviewed systematically, and the reported data were aggregated using the statistical techniques of meta-analysis. RESULTS: We found 3810 cases with lung cancer and 4332 controls from seven eligible studies. T19007C polymorphism showed no significant effect on lung cancer risk (C allele vs. T allele: odds ratio (OR) = 0.91, 95% confidence interval (CI) = 0.80 - 1.04; CC vs. TT: OR = 0.76, 95%CI = 0.56 - 1.02; CC vs. (CT + TT): OR = 0.96, 95%CI = 0.84 - 1.10). Similarly, there was no significant main effects for T19007C polymorphism on lung cancer risk when stratified analyses by ethnicity (Chinese or Caucasian). No significant association was found between C8092A polymorphism (3060 patients and 2729 controls) and the risk of lung cancer (A allele vs. C allele: OR = 1.03, 95%CI = 0.95 - 1.11; AA vs. CC: OR = 1.08, 95%CI = 0.88 - 1.33; AA vs. (AC + CC): OR = 1.08, 95%CI = 0.88 - 1.31). CONCLUSION: We found little evidence of an association between the T1900C or C8092A polymorphisms of ERCC 1 and the risk of lung cancer in Caucasian or Han Chinese people.
Subject(s)
DNA-Binding Proteins/genetics , Endonucleases/genetics , Lung Neoplasms/genetics , Polymorphism, Genetic/genetics , Asian People/genetics , Genetic Predisposition to Disease/genetics , HumansABSTRACT
Published data on the association between vascular endothelial growth factor (VEGF) -2578C/A polymorphism and cancer risk is inconclusive. To derive a more precise estimation of association between VEGF -2578C/A polymorphism and the risk of cancer, we performed a meta-analysis of 5415 cancer cases and 5848 controls from 16 published case-control studies. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association. Our meta-analysis indicated that VEGF -2578C/A polymorphism was associated with the risk of colorectal cancer under homozygote comparison (OR=0.70, 95% CI=0.53-0.92), dominant model (OR=0.72, 95% CI=0.57-0.92), and recessive model (OR=0.82, 95% CI=0.67-1.01), although no evidence of association between VEGF -2578C/A polymorphism and cancer risk was observed as we compared in the pooled analyses (homozygote comparison: OR=0.97, 95% CI=0.81-1.16). More studies are needed to detect VEGF -2578C/A polymorphism and its association with cancer in different ethnic populations incorporated with environmental exposures in the susceptibility of different kinds of cancer.
Subject(s)
Genetic Predisposition to Disease , Neoplasms/genetics , Polymorphism, Single Nucleotide , Vascular Endothelial Growth Factor A/genetics , Case-Control Studies , Female , Humans , Male , Risk FactorsABSTRACT
BACKGROUND AND AIMS: A number of investigators have studied the possible association between vascular endothelial growth factor (VEGF) polymorphisms and cancer risk, but the results have been conflicting. To examine the risk of cancer associated with the +936C/T and +405G/C polymorphisms of VEGF, all available studies were considered in the present meta-analysis. METHODS: We performed a computerized search of PubMed and Embase database for relevant studies. Articles meeting the inclusion criteria were reviewed systematically, and the reported data were aggregated using the statistical techniques of meta-analysis. RESULTS: Overall, the 936C allele showed no significant effect on cancer risk compared with the 936T allele in all subjects (OR = 0.77, 95% CI = 0.53-1.14; random model). Similarly, no significant effect of 405G allele compared with 405C on cancer risk was found (OR = 1.08, 95% CI = 0.94-1.24; random model). It indicated that the VEGF +936C/T and +405G/C polymorphisms might not be risk factors for cancer, but the 936C allele was associated with a decreased risk of oral cancer (OR = 0.72, 95% CI = 0.53-0.97; fixed model). CONCLUSIONS: The evidence from our meta-analysis supports that there was an association between 936C allele and decreased oral cancer risk, although no evidence of association between VEGF +936C/T or +405G/C polymorphism and cancer was observed in all examined patients. Further studies based on larger, stratified population are required to explore the role of VEGF polymorphisms on cancer risk.
