The genetic diversity of multiple sclerosis risk among Hispanic and African American populations living in the United States.

BACKGROUND: Substantial progress has been made toward unraveling the genetic architecture of multiple sclerosis (MS) within populations of European ancestry, but few genetic studies have focused on Hispanic and African American populations within the United States. OBJECTIVE: We sought to test the relevance of common European MS risk variants outside of the major histocompatibility complex (n = 200) within these populations. METHODS: Genotype data were available on 2652 Hispanics (1298 with MS, 1354 controls) and 2435 African Americans (1298 with MS, 1137 controls). We conducted single variant, pathway, and cumulative genetic risk score analyses. RESULTS: We found less replication than statistical power suggested, particularly among African Americans. This could be due to limited correlation between the tested and causal variants within the sample or alternatively could indicate allelic and locus heterogeneity. Differences were observed between pathways enriched among the replicating versus all 200 variants. Although these differences should be examined in larger samples, a potential role exists for gene-environment or gene-gene interactions which alter phenotype differentially across racial and ethnic groups. Cumulative genetic risk scores were associated with MS within each study sample but showed limited diagnostic capability. CONCLUSION: These findings provide a framework for fine-mapping efforts in multi-ethnic populations of MS.

A gene pathway analysis highlights the role of cellular adhesion molecules in multiple sclerosis susceptibility.

Genome-wide association studies (GWASs) perform per-SNP association tests to identify variants involved in disease or trait susceptibility. However, such an approach is not powerful enough to unravel genes that are not individually contributing to the disease/trait, but that may have a role in interaction with other genes as a group. Pathway analysis is an alternative way to highlight such group of genes. Using SNP association P-values from eight multiple sclerosis (MS) GWAS data sets, we performed a candidate pathway analysis for MS susceptibility by considering genes interacting in the cell adhesion molecule (CAMs) biological pathway using Cytoscape software. This network is a strong candidate, as it is involved in the crossing of the blood-brain barrier by the T cells, an early event in MS pathophysiology, and is used as an efficient therapeutic target. We drew up a list of 76 genes belonging to the CAM network. We highlighted 64 networks enriched with CAM genes with low P-values. Filtering by a percentage of CAM genes up to 50% and rejecting enriched signals mainly driven by transcription factors, we highlighted five networks associated with MS susceptibility. One of them, constituted of ITGAL, ICAM1 and ICAM3 genes, could be of interest to develop novel therapeutic targets.

Bevacizumab in metastatic breast cancer: a meta-analysis of randomized controlled trials.

Numerous studies have demonstrated that angiogenesis and in particular VEGF over-expression play an essential role in the progression and metastatic potential of breast cancer. Bevacizumab is a humanized recombinant monoclonal antibody that specifically blocks the binding of VEGF to high-affinity receptors and it has been recently used for the treatment of metastatic breast cancer. We conducted a meta-analysis to synthesize available evidence for use of bevacizumab in metastatic breast cancer patients. Systematic review and meta-analysis of available trials. Primary outcomes were overall survival, progression free survival (PFS) and objective response rate (ORR). Five trials were identified with 3,163 eligible patients. Combination of bevacizumab and chemotherapy resulted in a statistically significant improvement in PFS (HR = 0.70, 95% CI 0.60-0.82, P = 9.3 x 10(-6)) and ORR (RR = 1.26, 95% CI 1.17-1.37, P = 9.96 x 10(-9)) compared with chemotherapy alone. Differences in objective response rates were substantial independently by the type of chemotherapy used, while PFS advantages were observed only for taxanes. The pooled HR for overall survival did not show significant advantage for the use of bevacizumab compared to placebo arm (HR = 0.90, 95% CI 0.80-1.03, P = 0.119). This meta-analysis shows that the addition of bevacizumab to chemotherapy offers meaningful improvement in PFS and ORR in patients with metastatic breast cancer. Bevacizumab treatment might be suggested for treatment of 1st line metastatic breast cancer, but more data are needed until statistical overall survival differences will be documented and firm guideline recommendation could be given.

Industry sponsorship and selection of comparators in randomized clinical trials.

BACKGROUND: Most clinical trials on medical interventions are sponsored by the industry. The choice of comparators shapes the accumulated evidence. We aimed to assess how often major companies sponsor trials that involve only their own products. METHODS: Studies were identified by searching ClinicalTrials.gov for trials registered in 2006. We focused on randomized trials involving the 15 companies that had sponsored the largest number of registered trials in ClinicalTrials.gov in that period. RESULTS: Overall, 577 randomized trials were eligible for analysis and 82% had a single industry sponsor [89% (166/187) of the placebo-control trials, 87% (91/105) of trials comparing different doses or ways of administration of the same intervention, and 78% (221/285) of other active control trials]. The compared intervention(s) belonged to a single company in 67% of the trials (89%, 81% and 47% in the three categories respectively). All 15 companies strongly preferred to run trials where they were the only industry sponsor or even the only owner of the assessed interventions. Co-sponsorship typically reflected co-ownership of the same intervention by both companies. Head-to-head comparison of different active interventions developed by different companies occurred in only 18 trials with two or more industry sponsors. CONCLUSIONS: Each company generates a clinical research agenda that is strongly focused on its own products, while comparisons involving different interventions from different companies are uncommon. This diminishes the ability to understand the relative merits of different interventions for the same condition.