Building a Knowledge Base on Genetic Variation and Cancer Risk Through Field Synopses

Extract

The number of assessed genetic associations has grown tremendously in the past few years ( 1 ), especially with the recent advent of genome-wide association studies (GWAS) ( 2 ). However, the nonreplication of findings across multiple studies remains a documented issue for human genome epidemiology, even in the GWAS era ( 3 , 4 ). It has been recommended that systematic reviews including meta-analyses be conducted to assess or adjust for factors that may contribute to the nonreplication of research findings ( 5 ). However, meta-analyses still represent a small minority of the published articles on genetic associations and thus many frequently studied genetic associations have not been examined in meta-analyses ( 6 ). Indeed, Janssens et al. ( 7 ) recently found that only about half of genes included in genomic profiles sold by several companies to provide consumers with their risk of developing common diseases had undergone formal meta-analyses. This is a matter of concern given that the majority of the genetic associations in these meta-analyses had synthetic odds ratios that were not different from unity ( 7 ).