Regulatory cytokine gene polymorphisms and risk of colorectal carcinoma

IL-10 polymorphism genotypes, haplotypes, and diplotypes are associated with colorectal cancer predisposition and outcome in Tunisian population

Background and aim

As the presence of single nucleotide polymorphisms (SNPs) in the interleukin (IL)-10 gene continues to be a major challenge in the development of effective therapies for digestive cancers, this case-control study was conducted to assess the possible influence of genotype, haplotype and diplotype for two SNPs (-1082A/G (rs1800896) and -592A/C (rs1800872)) located in the promoter region of IL-10 gene on the incidence, severity and prognosis of colorectal cancer (CRC) in Tunisians.

Methods

IL-10 gene SNPs were analyzed in 130 CRC cases and 165 healthy subjects (HS) using PCR-SSP.

Results

For the IL-10 -1082A/G SNP, the comparison of genotype frequencies between cases and HS groups showed that the G allele significantly reduced CRC risk under the recessive model (GG vs. AA + AG: OR [95%CI] = 0.44 [0.21-0.93], p = 0.03). Conversely, a positive association was observed between the codominant model (AG vs. AA + GG) and high susceptibility (OR [95%CI] = 1.65 [1.02-2.63], p = 0.04). After stratification by disease site, the recessive model was also found to reduce susceptibility to colon cancer (OR [95%CI] = 0.18 [0.04-0.72], p = 0 0.01), while the homozygote model (AA vs. GG) was suggested as a risk factor (OR [95%CI] = 5.16 [1.31-23.26], p = 0.02). Furthermore, the codominant model (AG vs. AA + GG) doubled the risk of rectum cancer (OR [95%CI] = 1.98 [1.07-3.70], p = 0.03). For the IL-10 -592A/C SNP, the codominant model (AC vs. AA + CC) has a protective effect against the development of CRC (OR [95%CI] = 0.59 [0.36-0.94], p = 0.03). The IL-10 gene haplotype was not associated with CRC risk. A stratified analysis by disease site demonstrated that the presence of Hap3 (-1082G and -592C alleles) specifically reduced the risk of developing colon cancer (OR [95%CI] = 0.51 [0.32-0.80], p = 0.003). Moreover, homozygous Hap3/Hap3 diplotype significantly reduced susceptibility to CRC (OR [95%CI] = 0.35 [0.14-0.85], p = 0.02). Interestingly, this diplotype has not been identified in colon cancer patients. Kaplan-Meier analysis showed that the homozygous Hap2/Hap2 diplotype was significantly associated with decreased overall survival (Log-rank: p = 0.01). This association was also observed in the colon cancer subgroup (Log-rank: p = 0.001).

Conclusion

Our findings provide preliminary indications that the -1082A/G and -592/AC SNPs within the IL-10 gene may exhibit significant associations with the pathogenesis and prognostic outcomes of CRC. However, further investigations are still warranted to validate and establish the veracity of our findings.

Association of Interleukin-10 Polymorphisms with Susceptibility to Colorectal Cancer and Gastric Cancer: an Updated Meta-analysis Based on 106 Studies

BACKGROUND

The purpose of this study was to explore the association of IL-10 polymorphisms with susceptibility to colorectal cancer (CRC) and gastric cancer (GC).

METHODS

PubMed, Scopus, Embase, SciELO, medRxiv, China Biology Medicine Disc, DeepDyve, CNKI, and Web of Science were used to identify all relevant articles published up to 20th June 2021, without any restrictions on ethnicity. Summary odds ratios (ORs) with 95% confidence intervals (CIs) were used to determine the strength of the associations.

RESULTS

A total of 106 case-control studies were included. For CRC, 15 studies with 2772 cases and 3719 controls on -1082A/G, 11 studies with 3259 cases and 4992 controls on -592C/A, and 3 studies with 477 cases and 544 controls on -819 T/C were selected. For GC, 31 studies with 6229 cases and 8666 controls on -1082A/G, 27 studies with 5457 cases and 8381 controls on -592C/A, and 19 studies with 3556 cases and 6218 controls on -819 T/C were included. Pooled data showed a significant association between IL-10-819 T/C polymorphism and CRC susceptibility in overall population, but not for IL-10-1082A/G and -592C/A polymorphisms. However, IL-10-592C/A polymorphism was associated with CRC risk in Asians. A significant association of IL-10-1082A/G polymorphism with the GC risk was found. In the ethnicity subgroup analysis, a significant association was found between IL-10-1082A/G polymorphism and GC risk among Asians. The IL-10-819 T/C was not associated with GC risk in overall population and by ethnicity.

CONCLUSIONS

Our pooled data show a significant association of IL-10-819 T/C and IL-10-1082A/G polymorphisms with CRC and GC in overall population, respectively. However, other factors may influence these associations, and large-scale studies with adequate methodological quality are necessary to confirm the impact on CRC and GC risk.

Cumulative Evidence for Association Between IL-8 -251T>A and IL-18 -607C>A Polymorphisms and Colorectal Cancer Susceptibility: a Systematic Review and Meta-analysis

PURPOSE

The correlation of IL-8 and IL-18 gene polymorphisms with colorectal cancer (CRC) was investigated by previous studies, though the results remained conflicting. Thus, the meta-analysis was performed to investigate the association of IL-8 -251T>A and IL-18 -607C>A polymorphisms with CRC risk.

METHODS

A comprehensive search of the PubMed, Web of Science, CNKI, SciELO, and Wanfang databases was performed up to February 20, 2020. The strength of the associations was calculated with odds ratios (ORs) and their corresponding 95% of confidence intervals (CIs).

RESULTS

A total of 16 case-control studies including 13 studies with 3908 cases and 5005 controls on IL-8 -251T>A polymorphism and three studies with 396 cases and 560 controls on IL-18 -607C>A polymorphism were selected. Pooled data revealed that the IL-8 -251T>A and IL-18 -607C>A polymorphisms were not significantly associated with an increased risk of CRC in global population. When stratified by ethnicity, source of controls, sample size, and Hardy-Weinberg equilibrium (HWE), there were still no significant association between IL-8 -251T>A polymorphism and risk of CRC.

CONCLUSIONS

Our results revealed that the IL-8 -251T>A and IL-18 -607C>A polymorphisms were not associated with an increased susceptibility to CRC. We strongly call for further studies with larger sample sizes and different ethnicities to confirm our findings.

Helicobacter pylori and Epstein-Barr Virus Infection in Gastric Diseases: Correlation with IL-10 and IL1RN Polymorphism

Introduction

Helicobacter pylori and Epstein–Barr virus (EBV) infection have recently been shown to be associated with gastric diseases. Polymorphisms in genes encoding cytokines such as interleukin 10 (IL-10) and interleukin 1 Receptor (IL-1RN) influence cytokine secretion levels and appear to contribute to the risk of developing gastroduodenal diseases. To our knowledge, this is the first preliminary study to address the association of coinfection with H. pylori and EBV and their correlation with genetic predisposition in the development of gastric diseases.

Methods

Gastric biopsy samples of 96 patients with different gastric diseases were used.

Results

Our results showed that the rate of coinfection was higher in patients with gastric cancer than in patients with normal gastric mucosa, active chronic gastritis, and MALT lymphoma. As regards the characterization of H. pilory strains, the polymorphism s1m1i1 of vacA gene was more frequent in patients with MALT Lymphoma in comparison to others, while the polymorphism s2m2i2 was most frequent in patients with normal gastric mucosa. In addition, patients who tested positive for the cagA gene were more frequently those affected with gastric cancer than those with inactive chronic gastritis. Similarly, the patients with oipA gene ON were more frequently those with gastric cancer than those with inactive chronic gastritis.

Conclusion

According to our analysis, there was no correlation between coinfection and polymorphisms in genes encoding IL-10 and IL-1RN. We conclude that various factors can be involved in the development of gastric diseases.

ASSOCIATION OF PROMOTER REGION POLYMORPHISMS OF INTERLEUKIN-10 GENE WITH SUSCEPTIBILITY TO COLORECTAL CANCER: A SYSTEMATIC REVIEW AND META-ANALYSIS

BACKGROUND

Several epidemiological studies have investigated the association of promoter region polymorphisms of Interleukin-10 (IL-10) gene with colorectal cancer (CRC), while the conclusion is still conflicting and inconclusive.

OBJECTIVE

We conducted this meta-analysis to evaluate the association of promoter region polymorphisms of IL-10 with CRC.

METHODS

Eligible articles were identified by a search of several bibliographic databases for the period up to March 15, 2018. The strength of the association was measured by odd ratios with 95% confidence intervals.

RESULTS

A total of 28 case-control studies with 5,647 CRC cases and 6,908 controls were selected, including 14 studies for IL-10 -1082A>G (rs1800896) polymorphism (2,702 cases and 3,649 controls), eleven studies for -592C>A (rs1800872) polymorphism (3,259 cases and 4,992 controls), and three studies for -819T>C (rs1800871) polymorphism (477 cases and 544 controls). By pooling all eligible studies, we found that the IL-10 -1082A>G and -592C>A polymorphisms were not associated with increased CRC risk in overall population. However, there was significant associations between the IL-10 -819T>C polymorphism and CRC susceptibility under the allele model (A vs G: OR=1.278, 95% CI 1.043-1.566, P=0.018) and the recessive model (AA vs AG+GG: OR=1.709, 95% CI 1.026-2.845, P=0.039).

CONCLUSION

In this meta-analysis we found that IL-10 -819T>C polymorphism was associated with significantly increased risk of CRC; while the IL-10 -1082A>G and -592C>A polymorphisms were not associated with CRC risk. The IL-10 -819T>C polymorphism may be important as suspected predictive factor of CRC occurrence.

Association between interleukin-10 -592 A/C polymorphism and gastrointestinal tract cancer risk: A meta-analysis

BACKGROUND

Recent evidence suggests that -592 A/C polymorphism in the interleukin-10 (IL-10) gene may influence risk of gastrointestinal tract cancer; however, individual studies have provided conflicting and inconclusive results. Therefore, this meta-analysis was conducted to assess the association between IL-10 -592 A/C polymorphism and gastrointestinal tract cancer susceptibility.

METHODS

EMBASE, PubMed, Web of Science, and China National Knowledge Infrastructure databases were searched for case-control studies published before 1 May 2017. A total of 36 studies involving 8069 cases and 13,089 controls were included in the present meta-analysis according to the inclusion criteria. The random- or fixed-effect model was utilized to calculate pooled odds ratio (OR) with 95% confidence interval (CI), and to survey the association.

RESULTS

By and large IL-10 -592 A/C (rs1800872) polymorphism was not associated with gastrointestinal cancer risk in five genetic models (A vs. C: OR 1.00; 95% CI 0.93, 1.08; P_OR = 0.960; AA vs. CC: OR 0.98; 95% CI 0.85, 1.14; P_OR = 0.835; CA vs. CC: OR 1.01; 95% CI 0.94, 1.08; P_OR = 0.776; AA+CA vs. CC: OR 1.03; 95% CI 0.94, 1.12; P_OR = 0.592; AA vs. CA+CC: OR 0.98; 95% CI 0.87, 1.10; P_OR = 0.666). Similar results were also achieved after stratification by the Hardy-Weinberg equilibrium, ethnicity, source of controls, and cancer type.

CONCLUSION

The results of this meta-analysis indicated that there is no association between the IL-10 -592 A/C promoter polymorphism and gastrointestinal tract cancer susceptibility.

TGFβ1 Genetic Variants Predict Clinical Outcomes of HPV-Positive Oropharyngeal Cancer Patients after Definitive Radiotherapy

Purpose: TGFβ1 plays a critical role in inflammation and immune responses and treatment response and survival. TGFβ1 variants may affect its expression level or functional efficiency, thus modifying tumor status and survival in human papillomavirus (HPV)-positive squamous cell carcinoma of the oropharynx (SCCOP).Experimental Design: We determined tumor HPV16 status and genotyped three TGFβ1 polymorphisms in 564 incident SCCOP patients treated with radiotherapy or chemoradiation. Univariate and multivariable Cox models were used to evaluate the associations between the three polymorphisms and survival.Results: Overall, 85% of patients (482 of 564) had HPV16-positive SCCOP. We found that TGFβ1 rs1982073 had statistically significant associations with survival, whereas TGFβ1 rs1800469 and TGFβ1 rs1800471 did not. Patients with TGFβ1 rs1982073 CT/CC variant genotypes had significantly better overall, disease-specific, and disease-free survival compared with those with the corresponding common homozygous TT genotype (all log-rank: P < 0.001). Furthermore, these genotypes were significantly associated with an approximately 5 times reduced risk of overall death, death owing to disease, and recurrence after multivariable adjustment. Moreover, the stratified analyses by tumor HPV status indicated that the significant effects of TGFβ1 rs1982073 polymorphism on survival were found among HPV16-positive SCCOP patients only. Finally, the functional relevance of these variants was further characterized.Conclusions: Our findings support that the TGFβ1 rs1982073 polymorphism plays a significant role in the prognosis of SCCOP, especially in HPV16-positive SCCOP patients treated with chemoradiation. Prospective studies with larger sample sizes are needed to confirm these findings. Clin Cancer Res; 24(9); 2225-33. ©2018 AACR.

The association of three promoter polymorphisms in interleukin-10 gene with the risk for colorectal cancer and hepatocellular carcinoma: A meta-analysis

Mounting evidence supports a potent inhibitory role of interleukin-10 (IL-10) in tumor carcinogenesis, angiogenesis and metastasis. This meta-analysis was designed to examine the association of three promoter polymorphisms (−592C > A, −819C > T and −1082G > A) in IL-10 gene with the risk for colorectal cancer and hepatocellular carcinoma. Qualification assessment and data collection were completed by two authors independently. The random-effects model using the DerSimonian and Laird method was fitted by the STATA software. Twenty-five articles involving 5933 cases and 9724 controls were meta-analyzed. Overall comparisons of the mutant alleles (−592A, −819T and −1082A) of three promoter polymorphisms with alternative wild alleles failed to reveal any statistical significance for both colorectal cancer and hepatocellular carcinoma (P > 0.05), and the likelihood of heterogeneity was low (I² < 50%). For −592C > A polymorphism, a significant risk for colorectal cancer was identified when analysis was restricted to East Asians (odds ratio or OR = 1.41, 95% confidence interval or CI: 1.18–1.68, P < 0.001) and retrospective studies (OR = 1.23, 95% CI: 1.09–1.39, P = 0.001). As weighed by the Egger’s test and the fill-and-trim method, there was a low probability of publication bias for all studied polymorphisms. Our findings collectively suggest that the −592C > A polymorphism in IL-10 gene might be a susceptibility locus for colorectal cancer in East Asians.

A Causal Role of Genetically Elevated Circulating Interleukin-10 in the Development of Digestive Cancers: Evidence from Mendelian Randomization Analysis Based on 29,307 Subjects

Recent studies have observed a high level of circulating interleukin-10 (IL-10) in patients with digestive cancers, yet whether elevated IL-10 is causally associated with digestive cancers so far remained unresolved. We therefore meta-analyzed available observational studies with Mendelian randomization method to explore this causal association by employing IL-10 gene 3 variants (-592C>A, -819C>T, and -1082A>G) as instruments. Data were available from 52 articles encompassing 29,307 subjects. Subgroup analysis by cancer type indicated that -1082A>G was associated with increased risk of gastric cancer (odds ratio [OR] = 1.19; 95% confidence interval [CI]: 1.05-1.35; P = 0.006), and the association was reinforced for intestinal type gastric cancer (OR = 1.26; 95%CI: 1.09-1.44; P = 0.001). By ethnicity, risk estimate for -1082G allele carriers was increased by 21% for digestive cancers in East Asians (95%CI: 1.05-1.40; P = 0.009). As for the genotype-phenotype association, carriers of -1082G allele had an overall 20.21 pg/mL higher IL-10 level than those with -1082AA genotype (P = 0.023). In further Mendelian randomization analysis, the predicted OR for 10 pg/mL increment in IL-10 was 1.14 (95%CI: 1.01-16.99) in gastric cancer. Our findings provided evidence for a causal role of genetically elevated IL-10 in the development of gastric cancer, especially in East Asians and for intestinal type gastric cancer.

Significance of -1082A/G polymorphism of IL10 gene for progression of colorectal cancer and IL-10 expression

The role of functional polymorphism within IL10 (rs1800896) in colorectal cancer (CRC) still remains elusive. The aim of present study was to investigate the significance of -1082A/G polymorphism in IL10 on CRC risk, progression, and overall survival in a cohort of Bulgarian patients. Also, a functional role of this polymorphism on systemic and local level of IL10 mRNA quantity and serum IL-10 level was explored. A group of 119 patients with sporadic CRC and 154 age-sex-matched controls were genotyped by allele-specific PCR. The quantification of mRNA and serum IL-10 levels was performed by real-time PCR and ELISA assays, respectively. The genotype and allelic frequency among cases and controls was similar. However, we observed significant elevation of G-allele and GG-genotype frequencies among advanced CRC. G-allele was overrepresented in advanced CRC patients (49 %) compared to early CRC (35 %) with OR = 1.77; 95%CI 1.018 ÷ 3.083; P = 0.031. A significant upregulated expression of IL10 mRNA was observed among AG/GG-genotypes in tumor tissue compared to homozygous AA-genotype (RQ value 68.3 vs. 6.68; P = 0.0062). Also, GG-genotype of -1082A/G polymorphism in IL10 was positively associated with higher serum IL-10 among early CRC patients and controls, in contrast to advanced cases. Although, investigated polymorphism in IL10 has no significant impact of overall survival among Bulgarian CRC patients, we found a significant relationship of high pre-operative serum level of IL-10 with poor survival of CRC (P = 0.023). Our findings indicate a significant impact of -1082A/G polymorphism of IL10 on CRC progression, rather than genetic predisposition and prognosis of CRC.

The -1082A>G polymorphism in promoter region of interleukin-10 and risk of digestive cancer: a meta-analysis

The -1082A>G polymorphism is located in promoter region of interleukin-10 (IL-10) and it could affect the production of IL-10. Numerous studies have investigated the association between IL-10 -1082A>G and risk of digestive cancer. However, the conclusion is still inconsistent. Here, we have performed a meta-analysis and systematic review to determine the association between the IL-10 -1082A>G and susceptibility to digestive cancer. In this meta-analysis, we identified 40 eligible studies, involving 7195 patients of digestive cancer and 11755 controls. By pooling all eligible studies, we found the variant -1082G allele significantly increased risk of digestive cancer (G vs. A: OR = 1.181, 95% CI: 1.057-1.319). Further stratified analysis was performed to evaluate the influence of cancer types, ethnicities, study design, sample size and Hardy-Weinberg equilibrium. Stratified analysis suggested that, the -1082A>G polymorphism was only associated with increased risk for gastric cancer (G vs. A: OR = 1.281, 95% CI: 1.102-1.488) and in Asian population (G vs. A: OR = 1.399, 95% CI: 1.188-1.646). No significant publication bias was detected. Based on 40 studies and 18950 participants, we found the variant IL-10 -1082G allele significantly increased susceptibility to digestive cancer, especially for gastric cancer and in Asian population.

Relationships between genetic polymorphisms in inflammation-related factor gene and the pathogenesis of nasopharyngeal cancer

Our study aims to discuss the association between inflammation-related factors such as single nucleotide polymorphisms (SNPs) with susceptibility and recurrence in nasopharyngeal carcinoma. We used Taqman real-time polymerase chain reaction (PCR) to characterize the genetic variation of five SNPs in 194 nasopharyngeal carcinoma patients and 231 healthy subjects. All statistical analysis is performed with statistical product and service solutions v13.0; odds ratio (OR) value and 95 % confidence interval (CI) were calculated. There is no relationship between TGFβ1 -869 T/C, IL-6 -634C/G, TGFβ1 -509C/T, IL1 -511C/T and nasopharyngeal carcinoma susceptibility. Both single factor and multiple factors analysis showed that IL1a -889 T/T genotype is significantly associated with nasopharyngeal carcinoma in decreasing the risk of nasopharyngeal carcinoma. A highly significant association was found between IL1a -889 T/T genotype and protective genotype as defined by various pathological types. This is more obvious in the protective genotype of the non-keratin-type squamous carcinoma undifferentiated type. We also discovered that genotype G/G and C/G + G/G of IL6 -634 gene are associated with reduced recurrence of nasopharyngeal carcinoma. IL1a -889 gene polymorphism and susceptibility is related to nasopharyngeal carcinoma and can potentially decrease the risk of nasopharyngeal carcinoma in the Han Chinese population in north China. IL1-889 TT genotype is protective genotype for nasopharyngeal carcinoma. We have provided evidence that the GG genotype of the IL6 -634 gene is associated with recurrent risk of nasopharyngeal carcinoma. The G allele is the protective gene of nasopharyngeal carcinoma recurrence.

Polymorphisms of inflammation-related genes and colorectal cancer risk: a population-based case-control study in China

The previous studies found that chronic inflammation related to an increased risk of colorectal cancer (CRC). This study aims to explore the associations of polymorphisms in inflammation-related genes (IL10, IL10RA, IL6R, TNFRSF1A, TNFRSF1B, LTA and IL4) and their interactions with the risk of colorectal cancer among Chinese population. A population-based case-control study including 299 cases and 296 controls was conducted from January 2001 to December 2009. Multivariate unconditional logistic regression was used to analyse the association of nine SNPs in inflammation-related genes with the risk of CRC, colon cancer and rectal cancer, respectively. Generalized multifactor dimensionality reduction (GMDR) was implemented to explore the gene-gene interactions among all SNPs on CRC. A decreased risk of colorectal cancer in subjects with rs1800872 AC genotype of IL10 (OR = 0.643, 95%CI = 0.453, 0.912) or AC/CC genotype (OR = 0.636, 95%CI = 0.457, 0.885) was observed, compared with those with AA genotype. Meanwhile, similar associations were observed between rs1800872 and rectal cancer. Additionally, in rs1061624 of TNFRSF1B gene, AG genotype (OR=0.566; 95% CI= 0.362, 0.885) and AG/GG genotype (OR=0.638; 95% CI=0.420, 0.971) were significantly associated with a decreased risk of rectal cancer, respectively. Our findings indicated that mutants in IL10 and TNFRSF1B genes may change the CRC risk. However, there is no interaction between inflammation-related genes on CRC risk.

The interleukin 10 -819C/T polymorphism and cancer risk: a HuGE review and meta-analysis of 73 studies including 15,942 cases and 22,336 controls

The aim of the present work was to perform a meta-analysis to evaluate the association between the interleukin 10 (IL-10) -819C/T (rs1800871) polymorphism and cancer risk. A total of 73 studies, including 15,942 cancer cases and 22,336 controls, were identified in this meta-analysis. The odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using the random-effects model. Overall, no significant association was identified between the IL-10 -819C/T polymorphism and cancer risk. In the subgroup analyses, the T allele and TT genotype were associated with a moderately reduced cancer risk in the Asian population (T allele vs. C allele: OR=0.93, 95%CI: 0.87, 0.99; TT vs. CC: OR=0.86, 95%CI: 0.76, 0.98; TT vs. CT/CC: OR=0.90, 95%CI: 0.82, 0.98). Individuals who were homozygous for the T allele (TT) were found to be associated with significantly reduced gastric cancer risk in the Asian population. The heterozygous variant (CT) and the dominant model (TT/CT vs. CC) were associated with an increased risk for cervical and ovarian cancer. However, the IL-10 -819C/T polymorphism was not significantly associated with breast cancer, colorectal cancer, lung cancer, hepatocellular carcinoma, prostate cancer, lymphoma, or melanoma. The depressed cancer risk of the TT genotype occurred in the studies of hospital-based case-control studies and the studies recruited less than 500 subjects, but no statistically significant results were found in the stratified analyses using genotyping method. The results suggest that the IL-10 -819TT genotype may be a protective factor for cancer in Asians, especially gastric cancer. In contrast, the CT genotype and the dominant model could be risk factors for cervical and ovarian cancer. The importance of stratifying by ethnicity, cancer type, study design, and sample size needs to be standardized in future studies, together with considering the association between the IL-10 -819C/T polymorphism and cancer risk. Furthermore, the linkage of -819C/T with other polymorphisms of the IL-10 gene may help explain the variability in findings.

Transforming growth factor beta-1 C-509T polymorphism and cancer risk: a meta-analysis of 55 case-control studies

AIM

To investigate the association of transforming growth factor-beta 1 (TGF-β1) C-509T polymorphism and susceptibility to cancer by means of meta-analysis.

METHODS

An extensive search was performed to identify eligible case-control studies investigating such a link. The strength of the association between TGF-β1 C-509T polymorphism and cancer risk was assessed by pooled odds ratios (ORs) and 95%confidence intervals (95%CIs) in fixed or random effects models.

RESULTS

55 published case-control studies with a total number of 21,639 cases and 28,460 controls were included. Overall, there was no association between TGF-β1 C-509T and cancer risk in all genetic comparison models (TT vs. CC: OR=1.01, 95%CI=0.89-1.15; T vs. C: OR=1.01, 95%CI=0.94-1.07). However, a stratified analysis by cancer type indicated -509 T allele was significantly associated with decreased risk of colorectal cancer (CRC) (TT vs. CT/CC: OR=0.85, 95%CI=0.76-0.95), especially for Caucasians (TT vs. CT/CC: OR=0.83, 95%CI=0.71-0.98) and for population-based studies (TT vs. CT/CC: OR=0.78, 95%CI=0.68- 0.89).

CONCLUSION

This meta-analysis suggested that TGF-β1 C-509T polymorphism might contribute to a decreased risk on colorectal cancer susceptibility, especially for Caucasians.

The interleukin-10 promoter polymorphism rs1800872 (-592C>A), contributes to cancer susceptibility: meta-analysis of 16,785 cases and 19,713 controls

Interleukin-10 (IL-10) is a multifunctional cytokine which participates in the development and progression of various malignant tumors. To date, a number of case–control studies were conducted to detect the association between IL-10-592C>A polymorphism and cancer risk in humans. However, the results of these studies on the association remain conflicting. In an effort to solve this controversy, we performed a meta-analysis based on 70 case–control studies from 65 articles, including 16 785 cancer cases and 19 713 controls. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association. The overall results suggested that the variant homozygote genotype AA of the IL-10-592C>A polymorphism was associated with a moderately decreased risk of all cancer types (OR = 0.90, 95% CI = 0.83–0.98 for homozygote comparison, OR = 0.92, 95% CI = 0.86–0.98 for recessive model). In the stratified analyses, the risk remained for studies of smoking-related cancer, Asian populations and hospital-based studies. These results suggested that the IL-10-592C>A polymorphism might contribute to the cancer susceptibility, especially in smoking-related cancer, Asians and hospital-based studies. Further studies are needed to confirm the relationship.

An updated meta-analysis on the association of TGF-β1 gene promoter -509C/T polymorphism with colorectal cancer risk

AIM

Published data on the association between transforming growth factor-β1 (TGF-β1) gene promoter-509C/T polymorphism and colorectal cancer (CRC) risk are inconsistent and inconclusive. To derive a more precise estimation of this association, a meta-analysis was carried out.

METHODS

Meta-analysis was performed to evaluate reported studies of the relationship between TGF-β1 gene promoter-509C/T polymorphism and colorectal cancer risk using fixed-effects model and random-effects model.

RESULTS

We observed an increased colorectal cancer risk among subjects carrying TGF-β1 gene promoter-509CC+CT genotype (odds ratio (OR)=1.18%, 95% confidence interval (95% CI): 1.06-1.32) using 4440/6785 cases/controls in total population. We observed an increased risk of the TGF-β1 gene promoter -509CC, CT and CC+CT polymorphisms for colorectal cancer in population-based study (OR=1.36, 95% CI: 1.19-1.56, OR=1.18, 95% CI: 1.03-1.34 and OR=1.26, 95% CI: 1.12-1.43, respectively) in stratified analysis. We observed an increased colorectal risk among CC and CC+CT carriers in European and American population (OR=1.22, 95% CI: 1.04-1.43 and OR=1.18, 95% CI: 1.02-1.38, respectively). We also observed an increased risk of colon cancer among subjects carrying CC+CT genotype (OR=1.31, 95% CI: 1.05-1.63).

CONCLUSIONS

The present meta-analysis results suggest that TGF-β1 gene promoter -509C allele variant is a possible risk factor for developing colorectal cancer. Recommendations for further studies include pooling of individual data to verify results from the study and to facilitate evaluation of multigenic effects and detailed analysis of effect modification by environmental and lifestyle factors.

Meta-analysis of epidemiological studies of association of two polymorphisms in the interleukin-10 gene promoter and colorectal cancer risk

In order to make a comprehensive assessment of the potential association between two genetic variants in the IL-10 gene promoter, -1082 A>G (rs1800896) and -592 C>A (rs1800872), and colorectal cancer (CRC) risk, we conduced a meta-analysis of seven epidemiological studies, which included 1469 colorectal cancer cases and 2566 controls. Neither of the two polymorphisms had any association with increased CRC risk in overall population [for rs1800896: odds ratio (OR) = 0.90, 95% confidence interval (95%CI) = 0.76-1.06 in the dominant model and for rs1800872: OR = 1.06, 95%CI = 0.91-1.23 in the dominant model]. In subgroup analysis of the rs1800896 polymorphism, the results did not change when the analyses were restricted to individual studies, or those fulfilling Hardy-Weinberg equilibrium, or according to the source of controls. For rs1800872, however, when stratifying by the source of controls, the A allele had a significant increased risk of CRC among studies with population-based controls in the codominant model (AC vs CC: OR = 1.30, 95%CI = 1.04-1.63) and dominant model (AA/AC vs CC: OR = 1.25, 95% CI = 1.01-1.55). Based on this meta-analysis, we conclude that the IL-10 rs1800872 polymorphism could be a risk factor for CRC development among European populations. However, we found no association between the IL-10 rs1800896 polymorphism and CRC risk. Further studies, either with larger sample size or involving other SNPs and haplotypes of the IL-10 gene, are necessary to clarify the contribution of IL-10 genetic variations in colorectal carcinogenesis.

Correlation between TGF-β1-509 C>T polymorphism and risk of digestive tract cancer in a meta-analysis for 21,196 participants

The association between transforming growth factor β1 (TGF-β1)-509 C>T and risk of digestive tract cancer (DTC) remained uncertain as previous studies reported conflicting results. The aim of this study was to assess the association by using a meta-analysis. The databases of MEDLINE, EMBASE and WANGFANG (Chinese database) were retrieved, and latest update was on 2nd February, 2012. Pooled odds ratio and 95% confidence interval (OR and 95% CI) were calculated by using a fixed- or random-effect model. Ultimately, twenty nine case-control studies with 8664 cases and 12,532 controls were included in this meta-analysis. Overall, there was no association between TGF-β1-509 C>T and risk of DTC in all genetic comparison models (OR and 95% CI: 0.96 and 0.81-1.15 for TT vs. CC, 0.98 and 0.91-1.05 for T carriers vs. C carriers). When subgroup analyses were conducted according to ethnicity, types of cancer and sample size, T allele was significantly associated with decreased risk of DTC for Caucasians and for large sample-sized studies, and was associated with decreased risk of colorectal cancer (OR and 95% CI for TT vs. CC: 0.82 and 0.70-0.97 for Caucasians, 0.80 and 0.68-0.98 for large sample-sized studies, 0.78 and 0.62-0.97 for colorectal cancer). This study indicated that TGF-β1-509 C>T polymorphism was probably associated with risk of DTC, especially for Caucasians. Because of modest limitation, our findings should be confirmed by future studies.

Meta-analyses of the associations between four common TGF-β1 genetic polymorphisms and risk of colorectal tumor

The associations between four common genetic polymorphisms of transforming growth factor-β1 (TGF-β1 -509 C > T, +869 T > C, +915 G > C, and -800 G > A) and risk of colorectal tumor (including adenoma and cancer) have been widely studied. To date, no conclusions could be available because of controversial results reported. Thus, we conducted a meta-analysis to further assess the associations. We searched the databases of Medline, Embase, and Wangfang to identify eligible studies, and latest update was on January 1, 2012. Odds ratio (OR) and 95% confidence interval (95%CI) were calculated to present the associations. Our meta-analysis indicated that TGF-β1 -509 C > T, +869 T > C, +915 G > C, and -800 G > A were not associated with risk of colorectal adenoma (OR = 0.89 for C carriers vs. TT for -509 C > T, 1.03 for C carriers vs. TT for +869 T > C, 1.09 for C carriers vs. GG for +915 G > C, and 1.19 for A carriers vs. GG for 800 G > A). However, C allele of TGF-β1 -509 C > T and A allele of -800 G > A were associated with increased risk of colorectal cancer (CRC), and OR (95%CI) was 1.23 (0.99-1.52) for CC vs. TT for -509 C > T and 6.64 (3.46-12.72) for A carriers vs. GG. The positive association between -509 C allele and risk of CRC was more obvious when subgroup analyses were conducted for population-based and large sample-sized studies as well as Caucasians. In contrast, we did not observed any associations between TGF-β1 +869 T > C, +915 G > C, and risk of CRC. This study indicated that C allele of TGF-β1-509 C > T and A allele of -800 G > A might contribute to the increased risk of CRC, and could be used as two of genetic marks for screening individuals at high risk of CRC. Because of modest limitation, large sample-sized studies were required to confirm the findings.

The interleukin-10-1082 promoter polymorphism and cancer risk: a meta-analysis

Interleukin-10 (IL-10) is a multifunctional cytokine with both immunosuppressive and anti-angiogenic properties and play an important role in the pathogenesis of cancer. IL-10-1082A>G polymorphism is the most extensively studied polymorphism in the IL-10 gene in cancer susceptibility. To date, a number of case-control studies were conducted to investigate the association between IL-10-1082A>G polymorphism and cancer risk in humans. However, the association between the IL-10-1082A>G polymorphism and cancer risk is still ambiguous. In an effort to solve this controversy, we performed a meta-analysis based on 61 case-control studies, including 14,499 cancer cases and 16,967 controls. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association. In the stratified analyses by specific cancer type, increased risk was found in lung cancer (OR = 3.16, 95% CI = 1.16-8.63 for GA versus AA; OR = 2.07, 95% CI = 1.16-3.70 for GG versus AA; OR = 3.17, 95% CI = 1.31-7.68 for GA/GG versus AA) and non-Hodgkin's lymphoma (OR = 1.18, 95% CI = 1.02-1.36 for GA versus AA; OR = 1.17, 95% CI = 1.02-1.35 for GA/GG versus AA). The meta-analysis also indicated that the variant genotypes were associated with a moderately increased risk in Asians in all genetic models (OR = 1.80, 95% CI = 1.17-2.76 for GA versus AA; OR = 3.32, 95% CI = 1.62-6.82 for GG versus AA; OR = 1.67, 95% CI = 1.07-2.60 for GA/GG versus AA; OR= 2.93, 95% CI = 1.43-6.03 for GG versus AA/GA). The meta-analysis suggested that the IL-10-1082A>G polymorphism was associated with increased risk of cancer in Asians and lung cancer and non-Hodgkin's lymphoma. To draw comprehensive and true conclusions, more researches with larger numbers of worldwide participants are needed to examine associations between IL-10-1082A>G polymorphism and cancer risk.

Current management of inflammatory bowel disease and colorectal cancer

INFLAMMATORY BOWEL DISEASES (IBDS) CAN BE DIVIDED INTO TWO MAJOR DISORDERS: ulcerative colitis and Crohn's disease. Although IBD-associated colorectal cancer (IBD-CRC) accounts for only 1-2% of all cases of colorectal cancer, IBD with colon involvement is among the top three high-risk conditions for colorectal cancer. Today, colorectal cancer accounts for approximately 10-15% of all deaths among IBD patients. Indeed, patients with IBD colitis are six times more likely to develop colorectal cancer than the general population and have a higher frequency of multiple synchronous colorectal cancers. Since IBD-CRC was first described in 1925, the colon remains the primary site of neoplasms in IBD patients today. Ulcerative colitis-associated colorectal cancer is most common in the rectum and sigmoid colon, whereas Crohn's disease-associated colorectal cancer is evenly distributed between the different colon segments. Chemoprevention of colorectal cancer remains an important goal, and colonoscopy surveillance programs are critical to early detection in these patients. Newer methods, such as chromoendoscopy, are currently being investigated as complementary techniques to enhance early detection of dysplasia and cancer in this high-risk population. We present a comprehensive review of the relationship between inflammatory bowel disease and colorectal cancer. Major themes covered include risk factors for IBD-CRC and the molecular pathobiology of progression from dysplasia to cancer, endoscopic surveillance and new methods for early detection of dysplasia, approaches to prevention of IBD-CRC, and current recommendations and controversies regarding the treatment of dysplasia. In particular, disagreement has arisen over optimal management of low-grade dysplasia, with some IBD experts now advocating close colonoscopic surveillance of patients with low-grade dysplasia rather then total colectomy.

TGFbeta1 T29C polymorphism and cancer risk: a meta-analysis based on 40 case-control studies

Transforming growth factor-beta1 (TGFbeta1) plays a significant role in regulating cellular proliferation and apoptosis. The TGFbeta1 T29C polymorphism reportedly affects cancer risk, but pertinent studies offer conflicting results. We therefore performed a meta-analysis based on 40 studies from 32 publications, assessing the strength of the association using odds ratios with 95% confidence intervals. Overall, no evidence has indicated that individuals carrying CC or CT genotypes had significantly increased cancer risks, compared with TT genotype carriers [CC vs. TT: odds ratio (OR)=1.10, 95% confidence interval (95% CI)=1.00-1.21, P=0.06; CT vs. TT: OR=1.07, 95% CI=0.99-1.16, P=0.09). However, stratified analysis by cancer type and ethnicity indicated a significantly increased risk of prostate cancer (CT vs. TT: OR=1.28, 95% CI=1.01-1.61, P=0.04) and cancer in those of Asian descent (CC vs. TT: OR=1.26, 95% CI=1.03-1.53, P=0.02; CT vs. TT: OR=1.20, 95% CI=1.01-1.43, P=0.04). This association was also observed in the dominant model for prostate cancer. Although not all bias could be eliminated, this meta-analysis suggested that TGFbeta1 29C was a low-penetrant risk factor for prostate cancer and cancer in Asians. A larger single study is still required to evaluate any association with other types of cancer or in other populations.

TGFB1 509 C/T polymorphism and colorectal cancer risk: a meta-analysis

Transforming growth factor β (TGF-β) is a cytokine. The TGF-β signaling pathway plays an important role in controlling cell proliferation and differentiation involved in colorectal carcinogenesis. In mammalian cells, TGFB1 is the most abundant subtype of TGF-β. The 509 C/T polymorphism in TGFB1 has been implicated in colorectal cancer risk. However, published data remain conflicting. To derive a more precise estimation of the relationship, a meta-analysis of 994 cases and 2,335 controls from five published case-control studies was performed. Overall, significantly increased colorectal cancer risks were found for CC versus TT (OR=1.62; 95% CI: 1.30-2.02; Pheterogeneity=0.118), TC+CC versus TT (OR=1.30; 95% CI: 1.08-1.58; Pheterogeneity=0.259) and CC versus TC+TT (OR=1.48; 95% CI: 1.26-1.75; Pheterogeneity=0.244). In the subgroup analysis by ethnicity, significantly increased risks were also found among Asians for CC versus TT (OR=1.77; 95% CI: 1.40-2.24; Pheterogeneity=0.519), TC+CC versus TT (OR=1.38; 95% CI: 1.13-1.68; Pheterogeneity=0.679) and CC versus TC+TT (OR=1.58; 95% CI: 1.31-1.89; Pheterogeneity=0.340). However, no significant associations were found among Europeans for all genetic models. This meta-analysis showed that TGFB1 509 C allele is a risk factor for developing colorectal cancer in Asians.

Carcinogenesis in IBD: potential targets for the prevention of colorectal cancer

In patients with IBD, chronic colonic inflammation increases the risk of colorectal cancer, perhaps because inflammation predisposes these tissues to genomic instability. Carcinogenesis in the inflamed colon seems to follow a different sequence of genetic alterations than that observed in sporadic cancers in the uninflamed colon. In this Review, we focus on the genetic alterations in colitis-associated colorectal cancer that contribute to the acquisition of the essential hallmarks of cancer, and on how those alterations differ from sporadic colorectal cancers. Our intent is to provide a conceptual basis for categorizing carcinogenetic molecular abnormalities in IBD, and for understanding how cancer-preventive therapies might target reversal of acquired abnormalities in specific biochemical pathways.

Genetic polymorphism in the transforming growth factor beta1 gene (-509 C/T and -800 G/A) and colorectal cancer

TGF-beta1 is a multifunctional cytokine that acts as both a tumor suppressor and a stimulator of tumor progression. Susceptibility to colorectal carcinoma may be affected by genetic factors. In this study, the association between -800 G/A and -509 C/T polymorphisms of the transforming growth factor beta1 gene, TGFB1, and susceptibility to colorectal cancer in Iranian patients was investigated. This study was conducted with 134 patients with colorectal carcinoma and 138 healthy controls matched for age and sex. Genotyping was performed on genomic DNA using polymerase chain reaction and restriction fragment length polymorphism. The genotype distributions and allele frequencies of the TGFB1 gene polymorphism at -509 C/T were significantly related to colorectal carcinoma. A lower frequency of 509T allele (41.8%) and TT genotype was observed in patients (21.6%) than in control subjects (52.9% and 29.7%, respectively) (P<0.035). At position 800, no significant differences in genotype distribution and allele frequencies between the patients and healthy controls was found (P>0.05). These data suggest that the genetic polymorphism at -509 C/T but not at -800 G/A of the TGFB1 gene may play a role in susceptibility of Iranian subjects for colorectal carcinoma.

TGFB1 and TGFBR1 polymorphic variants in relationship to bladder cancer risk and prognosis

The transforming growth factor-beta (TGF-beta) signalling pathway plays an important role in tumor development and progression. We aimed at analyzing whether 7 different common variants in genes coding for 2 key members of the TGF-beta signalling pathway (TGFB1 and TGFBR1) are associated with bladder cancer risk and prognosis. A total of 1,157 cases with urothelial cell carcinoma of the bladder and 1,157 matched controls where genotyped for 3 single nucleotide polymorphisms (SNPs) in TGFB1 (rs1982073, rs1800472, rs1800471) and an additional 3 SNPs and 1 indel polymorphism in TGFBR1 (rs868, rs928180, rs334358 and rs11466445, respectively). In the case-control study, we estimated odds ratios and 95% confidence intervals for each individual genetic variant using unconditional logistic regression adjusting for age, gender, study area and smoking status. Survival analysis was performed using the Kaplan-Meier method and Cox models. The endpoints of interest were tumor relapse, progression and death from bladder cancer. All the SNPs analyzed showed a similar distribution among cases and controls. The distribution of the TGFBR1*6A allele (rs11466445) was also similar among cases and controls, indicating no association with bladder cancer risk. Similarly, none of the haplotypes was significantly associated with bladder cancer risk. Among patients with muscle-invasive tumors, we found a significant association between TGFBR1-rs868 and disease-specific mortality with an allele dosage effect (p-trend=0.003). In conclusion, the genetic variants analyzed were not associated with an increased risk of bladder cancer. The association of TGFBR1-rs868 with outcome should be validated in independent patient series.

Association of transforming growth factor-beta 1 polymorphisms with genetic susceptibility to TNM stage I or II gastric cancer

Transforming growth factor-beta 1 (TGF-beta1) inhibits the proliferation of tumors in early stages of cancers, whereas it promotes tumor growth and metastasis in later stages of cancers. To examine the effect of the TGF-beta1 polymorphisms on gastric cancer risk, we studied the association between C-509T and T+29C (Leu10Pro) polymorphisms in TGF-beta1 and gastric cancer risk in 414 cases and 414 controls in the Chinese population. When the overall gastric cancer cases were compared with the controls, no significant difference was found in genotype distributions for both the polymorphisms examined. However, when stratified by tumor stage, the -509T and +29C allele carriers had a 0.57-fold (95% CI = 0.36-0.90) and a 0.58-fold (95% CI = 0.36-0.91) decreased risk of TNM stage I+II gastric cancer, respectively, as compared with non-carriers. We conclude that TGF-beta1-509T and +29C alleles may have a protective role in the development of stage I+II gastric cancer.

Role of environmental and genetic factor interaction in age-related disease development: the gastric cancer paradigm

The association of Helicobacter pylori (Hp) infection with gastric cancer is well known and might be considered a paradigmatic example of the role that interaction among environmental factors and individual background might play in inducing age-associated disease. To evaluate the role of interaction of Hp infection with genetic background, gastric cancer and chronic gastritis patients as well as random selected controls were typed for five inflammation-related polymorphisms of IL-1 and IL-10 cytokine genes. No association among IL-10 or IL-1 variants with an increased risk of gastric cancer was found, whereas an Hp-independent association of IL-1beta -511T positive genotypes to an increased risk of chronic gastritis was found (Hp-/511T+ OR 1.89, 95% CI: 1.01-3.54; Hp+/-511T+ OR 1.83, 95% CI: 1.05-3.19). Stratification of gastric cancer group according to Hp infection does not allow finding a statistically significant association of Hp+ to the higher histological grading (G3) of gastric cancer (OR 1.54, 95% CI: 0.46-5.11). Our findings seem to confirm that cytokine genetic variants might contribute to determining the background for inflammaging in which H. pylori infection might facilitate cancer development.

Expression of deleted in pancreatic carcinoma locus 4 and transforming growth factor-β1 in human colorectal carcinoma and their clinical significance

AIM: To investigate the expression of deleted in pancreatic carcinoma locus 4 (DPC4) and transforming growth factor-β1 (TGF-β1) in human colorectal cancer tissues and their clinical significances.

METHODS: Forty-eight samples of human colorectal carcinoma were collected from patients from January 2005 to December 2005. In situ hybridization and immunohistochemistry were used to detect DPC4/TGF-β1 mRNA and protein expression respectively.

RESULTS: The expression of DPC4 mRNA was lower in colorectal carcinoma specimens as compared with that in normal colorectal specimens (52.1% vs 72.9%, P < 0.01), while TGF-β1 mRNA expression was higher in carcinoma specimens (68.8% vs 41.7%, P < 0.01). The level of DPC4 protein expression in the cancer specimens was significantly lower than that in the normal specimens, while TGF-β1 protein level were higher in the carcinoma specimens. DPC4 expression was related with the tumor size, clinical stages, differentiation degree and lymph node metastasis, while TGF-β1 expression was related with the clinic stage, differentiation degree and lymph node metastasis. There existed a close correlation between DPC4 and TGF-β1 expression (χ² = 3.95, P < 0.05).

CONCLUSION: DPC4 and TGF-β1 are the capital factors in TGF-β transduction pathway. Low-expression of DPC4 and over-expression of TGF-β1 may serve as an index for unfavorable prognosis of colorectal carcinoma.

Interleukin promoter polymorphisms and prognosis in colorectal cancer

There is strong evidence that cancer-associated inflammation promotes tumor growth and progression. This is especially true for colorectal cancer (CRC). Interleukins (ILs) are important modulators for inflammation. We examined whether promoter polymorphisms in key IL genes (IL4, IL4R, IL6, IL8 and IL10) are associated with the risk or clinical outcome of CRC. Five single-nucleotide polymorphisms (SNPs) were analyzed in genomic DNA from a cohort including 308 Swedish incident cases of CRC with data on Dukes' stage and up to 16 years of follow-up and 585 healthy controls. The selected SNPs have previously been shown to be functional and/or associated with cancer. None of the analyzed SNPs associated with the risk of CRC. When stratifying by tumor stage, significantly more patients carrying at least one G allele of IL10-1082 had tumors with Dukes' stages A + B than with stages C + D (P(trend) = 0.035 for genotype distribution). Analyzing associations with overall survival time, we found the rare T allele of IL4-590 to be related to a longer survival [CT versus CC Cox proportional hazard ratio 0.69, 95% confidence intervals 0.46-1.03, TT versus CC 0.32 (0.10-1.03)]. For IL6-174, the CG genotype was associated with a longer survival when compared with the CC genotype [0.64 (0.40-1.01)]. The present study was particularly suitable for survival analysis because all patients were sampled before the diagnosis of CRC. Our results suggest that the SNPs IL4-590 and IL6-174 may be useful markers for CRC prognosis. The predicted biological effect of these SNPs in relation to promotion of cancer progression is consistent with the observed increased survival time.

Correlation of transforming growth factor beta-1 gene polymorphisms C-509T and T869C and the risk of gastric cancer in China

BACKGROUND AND AIM

As an important cytokine that modulate the cell cycle, the involvement of transforming growth factor beta-1 (TGF-beta1) in carcinogenesis has been extensively studied for many years. Literatures have demonstrated that TGF-beta1 gene polymorphisms may alter the risk of various cancers, such as lung, prostate and breast. To investigate whether polymorphisms of the TGF-beta1 gene can modify the risk of gastric cancer, we conduct this hospital-based, case-control study.

METHODS

One hundred and sixty-seven cases and 193 gender, age-matched healthy controls were enrolled in this case-control study. TGF-beta1 polymorphisms C-509T and T + 869C were identified by PCR-RFLP and ARMS-PCR protocols, respectively.

RESULTS

Significantly different distributions of both genes were demonstrated between the case and control. Variant genotypes -509CT, -509TT, +869TC and +869CC were associated with increased risk of gastric cancer (P = 0.001, OR = 2.54; P = 0.016, OR = 2.09; P < 0.001, OR = 3.46; P < 0.001, OR = 4.04, respectively). With haplotype analysis, wild type CT (-509C and +869T) led to a lower frequency in case than that in control (P < 0.001), while haplotype TC was more frequent in case than in control (P < 0.001). Multiple logistic regression analysis revealed that individuals with haplotype TC had an increased likelihood of developing gastric cancer (OR = 3.19, 95%CI = 1.72-5.90).

CONCLUSIONS

Our findings imply that -509C > T and +869T > C gene polymorphisms in TGF-beta1 may be a critical risk factor of genetic susceptibility to gastric cancer in the Chinese population.