Search

Background: To evaluate relationship between the cyclooxygenase-2 promoter 765G/C polymorphism and digestive cancer risk in China., Materials and Methods: A literature search through February 2014 was performed using PubMed, Chinese Biomedical Literature Database (CBM) and China National Knowledge Infrastructure (CNKI) databases, and a meta-analysis was performed with RevMan 5.2 software for odds ratios and 95%CIs., Results: In total, 9 articles with 3,263 cases and 4,858 controls were included in this meta-analysis.The pooled OR (95%CIs) in the co-dominant model (GC vs GG) was 1.56 [1.19, 2.06], and in the dominant model ((CC+GC) vs GG), the pooled OR was 1.59 [1.21, 2.09] in overall cancers. In the subgroup analysis, stratified by cancer type, significant associations were found that the-765C allele had increased pancreatic cancer and gastric risk. No significant liver cancer and colorectal cancer risk of COX-2 -765G/C polymorphism was found., Conclusions: These findings suggest that COX-2-765*C is related to cancer susceptibility and may increase gastric and pancreatic cancer risk.

Background: A great number of studies have shown that cytochrome P450 1A1 (CYP1A1) genetic polymorphisms, CYP1A1 Msp I and CYP1A1 Ile/Val, might be risk factors for digestive tract cancers, including esophageal cancer (EC), gastric cancer (GC), hepatic carcinoma (HC), as well as colorectal cancer (CC), but the results are controversial. In this study, a meta-analysis of this literature aimed to clarify associations of CYP1A1 genetic polymorphisms with digestive tract cancer susceptibility in Chinese populations., Materials and Methods: Eligible case-control studies published until December 2013 were retrieved by systematic literature searches from PubMed, Embase, CBM, CNKI and other Chinese databases by two investigators independently. The associated literature was acquired through deliberate search and selection based on established inclusion criteria. Fixed- effects or random-effects models were used to estimate odds ratios (ORs and 95%CIs). The meta-analysis was conducted using Review Manager 5.2 and Stata 12.0 softwares with stability evaluated by both stratified and sensitivity analyses. Moreover, sensitivity analysis and publication bias diagnostics confirmed the reliability and stability., Results: Eighteen case control studies with 1, 747 cases and 2, 923 controls were selected for CYP1A1 MspI polymorphisms, and twenty case-control studies with 3, 790 cases and 4, 907 controls for the CYP1A1 Ile/ Val polymorphisms. Correlation associations between CYP1A1 Ile/Val polymorphisms and digestive tract cancers susceptibility were observed in four genetic models in the meta-analysis (GG vs AA:OR= 2.03, 95%CI =1.52- 2.72; AG vs AA: OR=1.26, 95%CI =1.07-1.48; [ GG+AG vs AA] :OR =1.42, 95%CI=1.20-1.68, [GG vs AA+AG ]:OR=1.80, 95%CI =1.40-2.31). There was no association between CYP1A1 Msp I polymorphisms and digestive tract cancer risk. Subgroup analysis for tumor type showed a significant association of CYP1A1 Ile/Val genetic polymorphisms with EC in China. However, available data collected by the study failed to reveal remarkable associations of GC or HC with CYP1A1 Ile/Val genetic polymorphisms and EC, GC or CC with CYP1A1 MspI genetic polymorphisms., Conclusions: Our results indicated that CYP1A1 Ile/Val genetic polymorphisms, but not CYP1A1 Msp I polymorphisms, are associated with an increased digestive tract cancer risk in Chinese population. Additional well-designed studies, with larger sample size, focusing on different ethnicities and cancer types are now warranted to validate this finding.

Matrix metalloproteinases (MMPs) degrade various components of the extracellular matrix and functional polymorphisms in encoding genes may contribute to genetic susceptibility to many cancers. Up to now, associations between MMP-7 (-181A>G) and digestive system cancer risk have remained inconclusive. To better understand the role of the MMP-7 (-181A>G) genotype in digestive cancer development, we conducted this comprehensive meta-analysis encompassing 3,518 cases and 4,596 controls. Overall, the MMP-7 (-181A>G) polymorphism was associated with higher digestive system cancer risk on homozygote comparison (GG vs. AA, OR=1.21, 95% CI = 1.12-1.60) and in a dominant model (GG/GA vs. AA, OR=1.16, 95% CI =1.03-1.46). On subgroup analysis, this polymorphism was significantly linked to higher risks for gastric cancer (GG vs. AA, OR=1.22, 95% CI = 1.02- 1.46; GA vs. AA, OR=1.82, 95% CI =1.16-2.87; GG/GA vs. AA, OR=1.13, 95% CI =1.01-1.27; GG vs. GA/AA, OR= 1.25, 95% CI = 1.06-2.39. We also observed increased susceptibility to colorectal cancer and esophageal SCC in both homozygote (OR = 1.13, 95% CI = 1.06-1.26) and heterozygote comparisons (OR = 1.45, 95% CI = 1.11-1.91). In the stratified analysis by controls, significant effects were only observed in population-based studies (GA vs. AA, OR=1.16, 95% CI=1.08-1.50; GA/AA vs. GG, OR=1.10, 95% CI=1.01-1.72). According to the source of ethnicity, a significantly increased risk was found among Asian populations in the homozygote model (GG vs. AA, OR=1.40, 95% CI=1.12-1.69), heterozygote model (GA vs. AA, OR=1.26, 95% CI=1.02-1.51), and dominant model (GG/GA vs. AA, OR=1.18, 95% CI=1.08-1.55). Our findings suggest that the MMP-7 (-181A>G) polymorphism may be a risk factor for digestive system cancer, especially among Asian populations.

NAD(P)H: quinone oxidoreductase 1 (NQO1) C609T gene polymorphisms have been reported to influence the risk for digestive tract cancer (DTC) in many studies; however, the results remain controversial and ambiguous. We therefore carried out a meta-analysis of published case-control studies to derive a more precise estimation of any associations. Electronic searches were conducted on links between this variant and DTC in several databases through April 2012. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to estimate the strength of associations in fixed or random effect models. Heterogeneity and publication bias were also assessed. A total of 21 case-control studies were identified, including 6,198 cases and 7,583 controls. Overall, there was a statistically significant association between the NQO1 C609T polymorphism and DTC risk (TT vs. CC: OR=1.224, 95%CI=1.055-1.421; TT/CT vs. CC: OR=1.195, 95%CI=1.073-1.330; TT vs. CT/CC: OR=1.183, 95%CI=1.029-1.359; T vs. C: OR=1.180, 95%CI=1.080-1.290). When stratified for tumor location, the results based on all studies showed the variant allele 609T might have a significantly increased risk of upper digest tract cancer (UGIC), but not colorectal cancer. In the subgroup analysis by ethnicity, we observed a significantly risk for DTC in Caucasians. For esophageal and gastric cancer, a significantly risk was found in both populations, and for colorectal, a weak risk was observed in Caucasians, but not Asians. This meta-analysis suggested that the NQO1 C609T polymorphism may increase the risk of DTC, especially in the upper gastric tract.

Malignancy is one of the main complications after renal transplantation but the situation in Chinese renal allograft recipients remains an enigma. We therefore reviewed 1,000 (8,531 person-years follow-up) renal allograft recipients from Jinling Hospital, Nanjing University, revealing an incidence rate of 2.4% of post-transplant malignancies, with a standardized incidence ratio (SIR) of 17.8 (95% C.I.: 16.7-18.8); the standardized rate is 1.67%, compared with 0.29% in the general population. However, our group demonstrated an extremely low incidence of skin cancer, which dominates in western countries. To confirm the findings, we reviewed the literature on post-transplant malignancies in Chinese renal allograft recipients, covering 296 malignancies in 18,548 renal transplant recipients in 21 reports. The top three most common sites of malignancies were the digestive tract, bladder and liver. The incidence of skin cancer was very low in most centers. These data show that Chinese renal allograft recipients have a unique spectrum of post-transplant malignancies, with an extremely very low incidence of skin cancer as compared to populations from western countries.