Relevance of hMLH1 -93G>A, 655A>G and 1151T>A polymorphisms with colorectal cancer susceptibility: a meta-analysis based on 38 case-control studies

SUMMARY OBJECTIVE: There has been increasing interest in the study of the association between human mutL homolog 1 (hMLH1) gene polymorphisms and risk of colorectal cancer (CRC). However, results from previous studies are inconclusive. Thus, a meta-analysis was conducted to derive a more precise estimation of the effects of this gene. METHODS: A comprehensive search was conducted in the PubMed, EMBASE, Chinese Biomedical Literature databases until January 1, 2018. Odds ratio (OR) with 95% confidence interval (CI) was used to assess the strength of the association. RESULTS: Finally, 38 case-control studies in 32 publications were identified met our inclusion criteria. There were 14 studies with 20668 cases and 19533 controls on hMLH1 −93G>A, 11 studies with 5,786 cases and 8,867 controls on 655A>G and 5 studies with 1409 cases and 1637 controls on 1151T>A polymorphism. The combined results showed that 655A>G and 1151T>A polymorphisms were significantly associated with CRC risk, whereas −93G>A polymorphism was not significantly associated with CRC risk. As for ethnicity, −93G>A and 655A>G polymorphisms were associated with increased risk of CRC among Asians, but not among Caucasians. More interestingly, subgroup analysis indicated that 655A>G might raise CRC risk in PCR-RFLP and HB subgroups. CONCLUSION: Inconsistent with previous meta-analyses, this meta-analysis shows that the hMLH1 655A>G and 1151T>A polymorphisms might be risk factors for CRC. Moreover, the −93G>A polymorphism is associated with the susceptibility of CRC in Asian population.

RESUMO OBJETIVO: Tem havido crescente interesse no estudo da associação entre polimorfismos do gene mutL homólogo 1 humano (hMLH1) e risco de câncer colorretal (CRC). No entanto, os resultados de estudos anteriores não são conclusivos. Assim, uma meta-análise foi conduzida para obter uma estimativa mais precisa dos efeitos desse gene. MÉTODOS: Uma pesquisa abrangente foi realizada nas bases de dados PubMed, Embase, Chinese Biomedical Literature até 10 de janeiro de 2018. Odds ratio (OR) com 95% de intervalo de confiança (IC) foi utilizado para avaliar a força da associação. RESULTADOS: Finalmente, foram identificados 38 estudos de casos e controles em 32 publicações, atendendo aos nossos critérios de inclusão. Houve 14 estudos com 20.668 casos e 19.533 controles em hMLH1 −93G>A, 11 estudos com 5.786 casos e 8.867 controles em 655A>G e cinco estudos com 1.409 casos e 1.637 controles em 1151T>Um polimorfismo. Os resultados combinados mostraram que os polimorfismos 655A>G e 1151T>A estavam significativamente associados ao risco de CRC, enquanto que o polimorfismo −93G>A não estava significativamente associado ao risco de CRC. Quanto à etnia, os polimorfismos de −93G>A e 655A>G foram associados ao risco aumentado de CRC entre os asiáticos, mas não entre os caucasianos. Mais interessante, a análise de subgrupos indicou que 655A>G pode aumentar o risco de CRC em subgrupos PCR-RFLP e HB. CONCLUSÃO: Inconsistente com a meta-análise anterior, esta meta-análise mostra que os polimorfismos hMLH1 655A>G e 1151T>A podem ser fatores de risco para CRC. Além disso, o polimorfismo −93G>A está associado à susceptibilidade do CRC na população asiática.

Association of angiotensin-converting enzyme insertion/deletion polymorphism with recurrent pregnancy loss: a meta-analysis of 26 case-control studies

Abstract Objective Previous studies investigating the association between angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and recurrent pregnancy loss (RPL) risk has provided inconsistent results. The aim of our study was to assess the association between the ACE I/D polymorphism and risk of RPL. Methods All studies published up to January 30, 2018 on the association of ACE I/D polymorphism with RPL were identified by searching the PubMed, Web of Knowledge, and Google scholar databases. Results A total of 26 case-control studies with 3,140 RPL cases and 3,370 controls were included in themeta-analysis. Overall, there was a significant association between ACE I/D polymorphism and RPL risk under the allele model (I versus D: odds ratio [OR] = 0.538, 95% confidence interval [CI] = 0.451-0.643, p 0.001), the homozygote model (II versus DD: OR = 0.766, 95% CI = 0.598-0.981, p = 0.035) and the recessive model (II versus ID + DD: OR = 0.809, 95% CI = 0.658-0.994, p = 0.044). Subgroup analysis by ethnicity showed that there was a significant association between ACE I/D polymorphism and increased risk of RPL in Caucasian and West-Asian populations, but not in East-Asians. When stratified by number of recurrent miscarriages (RMs), a significant association between ACE I/D polymorphism and increased risk of RPL was detected in the group of studies with ≥ 2 RMs, but not in studies with ≥ 3 RMs. Conclusion Themeta-analysis suggests that ACE I/D polymorphism is associated with increased risk of RPL. The ACE I/D polymorphism may be a risk factor for RPL in Caucasian and West-Asian populations, but not in East-Asians.

Association of Interleukin-10 -1082A>G (rs1800896) Polymorphism with Predisposition to Breast Cancer: a Meta-Analysis based on 17 Case-Control Studies

SUMMARY INTRODUCTION The association between the between IL-10 -1082A>G (rs1800896) polymorphism and breast cancer has been evaluated by several number case-control studies. However, these studies might be underpowered to reveal the true association. OBJECTIVE We have performed a comprehensive meta-analysis to investigate the association IL-10 -1082A>G polymorphism and breast cancer. MATERIALS AND METHODS A systematic literature search was conducted using PubMed, Google Scholar, and Web of Science up to September 20, 2017. Data was analysed with CMA software to identify the strength of the association by pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs). RESULTS A total of 17 case-control studies involving 3275 cases and 3416 controls obtained from database searches were examined. Overall, there was no significant association between IL-10 -1082A>G polymorphism and breast cancer risk under all genetic models. No significant publication bias was found for the five genetic models (G vs. A OR = 1.184, 95% CI = 0.895-1.180, p= 0.230; GG vs. AA: OR = 1.430, 95% CI = 0.927-2.204, p= 0.106; GA vs. AA: OR = 0.966, 95% CI = 0.765-1.221, p= 0.774; GG+GA vs. AA: OR = 0.957, 95% CI = 0.697-1.314, p= 0.786; and GG vs. GA+AA: OR = 1.221, 95% CI = 0.981-1.518, p= 0.073). Moreover, there was no significant association between the IL-10 -1082A>G polymorphism and breast cancer risk by ethnicity. CONCLUSION Our findings indicated that IL-10 -1082A>G (rs1800896) polymorphism might not be a risk factor for the development of breast cancer.

RESUMO

Associação de interleucina-10-1082A/polimorfismo G (rs1800896) com suscetibilidade a câncer gástrico: meta-análise de 6. 101 casos e 8. 557 controles / Association of interleukin-10 -1082 a/g (rs1800896) polymorphism with susceptibility to gastric cancer: meta-analysis of 6, 101 cases and 8, 557 controls

ABSTRACT BACKGROUND: The promoter -1082 A/G (rs1800896) polymorphism of Interleukin-10 (IL-10) gene have been widely reported and considered to have a significant role on gastric cancer risk, but the results are inconsistent. OBJECTIVE: To clarify the association, we conducted a meta-analysis to investigate the associations IL-10 -1082 A/G polymorphism with gastric cancer. METHODS: Eligible articles were identified by searching databases including PubMed, Web of Science, and Google Scholar up to August 03, 2017. Odds ratios (OR) with corresponding 95% confidence intervals (CIs) were used to assess the association. RESULTS: A total of 30 case-control studies with 6,101 cases and 8,557 controls were included in this meta-analysis. Overall, a significant association between IL-10 -1082 A/G polymorphism and gastric cancer risk was observed under the allele model (G vs A: OR=1.305, 95% CI=1.076-1.584; P=0.007), heterozygote model and (GA vs AA: OR=1.252, 95% CI=1.252-1.054; P=0.011) and dominant model (GG+GA vs AA: OR=1.264, 95% CI=1.053-1.516; P=0.012). In the subgroup analysis by ethnicity, increased gastric cancer risk were found in Asians under the allele model (G vs A: OR=1.520, 95% CI=1.172-1.973; P=0.002), homozygote model (GG+GA vs AA: OR=1.571, 95% CI=1.023-2.414; P= 0.039), heterozygote model (GA vs AA: OR=1.465, 95% CI=1.192-1.801; P≤0.001) and dominant model (GG+GA vs AA: OR=1.448, 95% CI=1.152-1.821; P=0.002), but not among Caucasian and Latinos populations. CONCLUSION: These results suggested that the IL-10 -1082 A/G (rs1800896) polymorphism might contribute to the gastric cancer susceptibility, especially among Asians.

RESUMO CONTEXTO: O promotor-1082 A/polimorfismo G (rs1800896) do gene da interleucina-10 (IL-10) é amplamente relatado e considerado por ter um papel significativo no risco de câncer gástrico, porém os resultados são inconsistentes. OBJETIVO: Para esclarecer melhor esta associação, realizou-se uma meta-análise para investigar as associações de IL-10-1082 A/polimorfismo G com câncer gástrico. MÉTODOS: Artigos elegíveis foram identificados através de pesquisa de bases de dados PubMed, Web of Science e Google Scholar até 3 de agosto de 2017. Razões de possibilidades (OR) com intervalo de confiança de 95% correspondente (CIs) foram usados para avaliar a associação. RESULTADOS: Um total de 30 estudos de caso-controle, 6.101 casos e com 8.557 controles foram incluídos nesta meta-análise. Em geral, uma associação significativa entre IL-10-1082 A/G polimorfismo e risco de câncer gástrico foi observada sob o modelo de alelo (G vs A: OR=1.305, 95% CI=1.076-1.584; P=0.007), no modelo heterozigoto (GA vs AA: OR=1.252, 95% CI=1.252-1.054; P=0.011) e modelo dominante (GG+GA vs AA: OR=1.264, 95% CI=1.053-1.516; P=0.012). Na análise de subgrupo pela etnia, foi encontrado risco aumentado de câncer gástrico em asiáticos sob o modelo de alelo (G vs A: OR=1.520, 95% CI=1.172-1.973; P=0.002), modelo heterozigoto (GG+GA vs AA: OR=1.571, 95% CI=1.023-2.414; P= 0.039), e modelo dominante (GG+GA vs AA: OR=1.448, 95% CI=1.152-1.821; P=0.002), mas não entre a população caucasiana e latina. CONCLUSÃO: Estes resultados sugeriram que a IL-10-1082 A/polimorfismo G (rs1800896) pode contribuir para a suscetibilidade de câncer gástrico, especialmente entre os asiáticos.