Epidemiological studies investigating the association of angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism with polycystic ovary syndrome (PCOS) produced inconsistent results. To derive a more precise estimation of the relationship between I/D polymorphism and PCOS, we conducted the current meta-analysis.

Meta-analysis of genomics data seeks to identify genes associated with a biological phenotype across multiple datasets; however, merging data from different platforms by their features (genes) is challenging. Meta-analysis using functionally or biologically characterized gene sets simplifies data integration is biologically intuitive and is seen as having great potential, but is an emerging field with few established statistical methods.

Cervical cancer is the third most common cancer in women worldwide. Persistent infection with an oncogenic human papillomavirus (HPV) is necessary, but not sufficient, for its development. Over many years, only a small proportion of women with chronic HPV infection progress to develop disease. The role of host genes and environmental factors in the pathogenesis of, or predisposition to, cervical cancer is still unclear. We conducted a systematic review of published literature in MEDLINE-PubMed to identify studies of cervical cancer susceptibility that used a twin study design. We used standard MeSH terms (controlled vocabulary) as well as specific free-text terms and combinations of terms related to cervical cancer, with no restriction on publication date. We performed a full text review to ensure the identified articles met our inclusion criteria and, if so, extracted information on demographics, sample size, study definitions, and key statistical findings. Of the 285 articles identified, three utilized a classical twin design and reported results specific to cervical cancer. The studies were based on cancer registry data from Scandinavia, with sample sizes ranging from 312 to 710 twin pairs. The findings from one study were consistent with a genetic mechanism for the causation of carcinoma in situ. Future research studies using the strength of the classic twin design, together with incorporation of HPV DNA status, are indicated to determine whether there is a potential role for genetic factors in the development of cervical cancer or high-grade cervical dysplasia from chronic oncogenic HPV infection.

CXCL12 is an important alpha-chemokine that regulates many essential biological processes including tumor development and metastasis. The CXCL12 G801A polymorphism is associated with multiple kinds of malignant cancer, but the associations are inconsistent. To derive a more precise estimation of the relationship, we conducted a meta-analysis of 16 publications with 2,888 cases and 3,611 controls. We used the odds ratio (OR) corresponding to 95% confidence interval (CI) to estimate the strength of association. The increased risk of overall cancer was found in the homozygote comparison (AA vs. GG, OR=1.43, 95℅CI=1.07-1.91), the recessive model (AA vs. GG+GA, OR=1.26, 95℅CI=1.03-1.54), and the dominant model (GA+AA vs. GG, OR=1.35, 95℅CI=1.15-1.58). In the stratified analyses, the associations were significant in breast cancer, Asians and hospital-based controls. In conclusion, this meta-analysis suggests that the CXCL12 G801A polymorphism may be a risk factor of cancer, especially in the subgroups of breast cancer, Asians and hospital-based controls.

Evidence is accumulating that chronic inflammation has an important role in prostate cancer. Two common polymorphisms in the prostaglandin-endoperoxide synthase 2 (PTGS2) gene, rs20417 and rs689470, have been found to alter the risk for prostate cancer, but the various studies are not in agreement. To derive a more precise estimation of this association, all available studies were considered in a meta-analysis, with 10,700 patients and 13,021 controls for rs20417 and 4087 patients and 3761 controls for rs689470. We used odds ratios (ORs) to assess the strength of the association, and 95% confidence intervals (CIs) to determine the precision of the estimate. When all groups were pooled, we did not detect a significant association of rs20417 polymorphism with prostate cancer risk. Similarly, no associations were found in the subgroup analysis. However, we found that rs689470 was significantly associated with a trend towards increased prostate cancer risk when using both additive (OR = 2.15, 95%CI = 1.04-4.44, P = 0.04) and recessive models (OR = 2.07, 95%CI = 1.07-4.03, P = 0.03) to analyze the data. In subgroup analyses stratified by ethnicity, there was no evidence that rs689470 has a significant association with prostate cancer in Caucasians. Based on our meta-analysis, rs689470 polymorphism is significantly associated with prostate cancer risk in the overall population. Nevertheless, we suggest that further studies should be made to confirm these findings.

p53 tumor suppressor gene Arg72Pro polymorphism has been associated with gastric cancer. However, results were inconsistent. We performed this meta-analysis to estimate the association between p53 Arg72Pro polymorphism and gastric cancer.

Little is known about frequency, association with clinical characteristics, and prognostic impact of DNA copy number alterations (CNA) on survival in central primitive neuroectodermal tumors (CNS-PNET) and tumors of the pineal region. Searches of MEDLINE, Pubmed, and EMBASE--after the original description of comparative genomic hybridization in 1992 and July 2010--identified 15 case series of patients with CNS-PNET and tumors of the pineal region whose tumors were investigated for genome-wide CNA. One additional case study was identified from contact with experts. Individual patient data were extracted from publications or obtained from investigators, and CNAs were converted to a digitized format suitable for data mining and subgroup identification. Summary profiles for genomic imbalances were generated from case-specific data. Overall survival (OS) was estimated using the Kaplan-Meier method, and by univariable and multivariable Cox regression models. In their overall CNA profiles, low grade tumors of the pineal region clearly diverged from CNS-PNET and pineoblastoma. At a median follow-up of 89 months, 7-year OS rates of CNS-PNET, pineoblastoma, and low grade tumors of the pineal region were 22.9 ± 6, 0 ± 0, and 87.5 ± 12 %, respectively. Multivariable analysis revealed that histology (CNS-PNET), age (≤2.5 years), and possibly recurrent CNAs were associated with unfavorable OS. DNA copy number profiling suggests a close relationship between CNS-PNET and pineoblastoma. Low grade tumors of the pineal region differed from CNS-PNET and pineoblastoma. Due to their high biological and clinical variability, a coordinated prospective validation in future studies is necessary to establish robust risk factors.

Dupuytren's disease (DD) is a common fibroproliferative disorder affecting the palmar fascia, which may lead to permanent contracture of the affected digit. Profiling studies investigating DD at whole-genomic, transcriptomic and proteomic levels have been carried out, from which large numbers of candidate genes potentially involved in DD have been reported. This review focuses on identifying genes reported by multiple studies or validated by multiple experimental techniques, as well as signalling pathways suggested to contribute to DD. Meta-analysis was also carried out on three microarray datasets. Twenty-one genes were found to be reported as dysregulated in multiple gene expression microarrays, seven of which have been further validated by other experimental methods. Sixty-four genes determined to be dsyregulated by meta-analysis correlate to those reported by published microarray studies. In addition, several pathways have been proposed to be involved in DD by whole-genome or global expression profiling. Further investigation in these genes and pathways, and correlating them to genotypes or environmental factors for DD, may aid in further elucidation of mechanisms involved in DD pathogenesis.

NAD(P)H:quinone oxidoreductase 1 (NQO1) and NRH:quinone oxidoreductase 2 (NQO2), involved in detoxification of environmental carcinogens and activation of chemotherapeutic agents, are supposed to play critical role in carcinogenesis. So, we aimed to investigate the association of NQO1 609C>T and NQO2 -3423G>A polymorphisms with susceptibility and prognosis of Esophageal cancer (EC) in north Indian population. We also performed Meta analysis of published literatures on NQO1 609C>T polymorphism to systematically evaluate its association with EC.

Xeroderma pigmentosum complementation group F (XPF or ERCC4) plays a key role in DNA repair that protects against genetic instability and carcinogenesis. A series of epidemiological studies have examined associations between XPF polymorphisms and cancer risk, but the findings remain inconclusive.

Single nucleotide polymorphisms (SNPs) in microRNA-coding genes may participate in the process of carcinogenesis by altering the expression of tumor-related microRNAs. It has been suggested that two common SNPs rs2910164 in miR-146a and rs11614913 in miR-196a2 are associated with susceptibility to hepatocellular carcinoma (HCC). However, published results are inconsistent and inconclusive. In the present study, we performed a meta-analysis to systematically summarize the possible association between the two SNPs and the risk for HCC.

Numerous studies have yielded inconclusive results regarding the relationship between tumor suppressor protein TP53 overexpression and/or TP53 gene mutations and the response to neoadjuvant chemotherapy in patients with breast cancer. The purpose of the current study was therefore to evaluate the relationship between TP53 status and response to chemotherapy in breast cancer.

Glutathione S-transferases (GSTs) genetic variants have been explored extensively as a predictive factor for cancer etiology. This meta-analysis aimed to examine the associations GSTM1, GSTT1, and GSTP1 genetic polymorphisms with thyroid cancer risk. PubMed, EMBASE, Cochrane Library, and HuGNet database were searched up to November 2011 using the appropriate terms. Twelve studies regarding GSTM1 null polymorphism (1569 cases and 2907 controls), 11 studies concerning GSTT1 null polymorphism (1515 cases and 2863 controls), and 8 studies on GSTP1 Ile105Val (965 cases and 1604 controls) were included in the meta-analysis. The random effects odds ratio was 1.07 (95% CI: 0.88-1.31; I(2) = 54.1%, P for heterogeneity = 0.013) for the GSTM1 null vs. present genotype and 1.08 (95% CI: 0.75-1.57; I(2) = 81.4%, P for heterogeneity < 0.001) for the GSTT1 null vs. present genotype, and 1.02 (95% CI: 0.70-1.49; I(2) = 74.6%, P for heterogeneity < 0.001) for the GSTP1 Val/Val+Val/Ile vs. Ile/Ile genotype. Similarly, no significant associations were demonstrated for subgroup analyses performed by ethnicity and histological type. In conclusion, these three polymorphisms are unlikely to be major determinants of susceptibility to thyroid cancer. Reasons for potential heterogeneity of effects, which could include true biologic heterogeneity, publication bias, or chance, deserve further investigation. The relationship between these three genes and thyroid carcinoma must be evaluated further with gene-gene and gene-environment interactions.

Recent studies on the association between miR-146a rs2910164 polymorphism and risk of gastrointestinal (GI) cancers showed inconclusive results. Accordingly, we conducted a comprehensive literature search and a meta-analysis to clarify the association.

To determine the pharmacogenetics of platinum-based chemotherapy in Non Small Cell Lung Cancer (NSCLC) patients.

The growing collection of publicly available high-throughput data provides an invaluable resource for generating preliminary in silico data in support of novel hypotheses. In this study we used a cross-dataset meta-analysis strategy to identify novel candidate genes and genetic variations relevant to paclitaxel/carboplatin-induced myelosuppression and neuropathy. We identified genes affected by drug exposure and present in tissues associated with toxicity. From ten top-ranked genes 42 non-synonymous single nucleotide polymorphisms (SNPs) were identified in silico and genotyped in 94 cancer patients treated with carboplatin/paclitaxel. We observed variations in 11 SNPs, of which seven were present in a sufficient frequency for statistical evaluation. Of these seven SNPs, three were present in ABCA1 and ATM, and showed significant or borderline significant association with either myelosuppression or neuropathy. The strikingly high number of associations between genotype and clinically observed toxicity provides support for our data-driven computations strategy to identify biomarkers for drug toxicity.

The objective of this study was to determine the relationship between specific genetic alterations and malignant transformation in intraductal papillary mucinous neoplasm (IPMN) of the pancreas.

The potentially functional polymorphism, rs909253 (+252 G>A), in the intron region of the LT-α (TNF-β) gene has been implicated in the risk of gastric cancer (GC) in some individually published studies, but others have shown inconsistent and inconclusive results.