Kokelaar RF, et al. - In this meta-analysis, researchers systematically searched PubMed, Embase, MEDLINE, PubMed Central, and Cochrane electronic databases for articles pertaining to CpG island methylator phenotype (CIMP) and rectal cancer to determine the prognostic significance of CIMP in rectal cancer. According to PRISMA standards, articles were analyzed and data extracted. In this analysis, six studies with 1,529 subjects were involved. A significant association was not seen between CIMP and poor outcomes in rectal cancer. The data presented in this work showed a high degree of heterogeneity in CIMP assessment methodologies and in study populations. Rectal cancer datasets were frequently not extractable from larger colorectal cohorts, which limited analysis.