Abstract: Particular aspects confirm the existence of a CpG island methylator phenotype (CIMP) in colorectal cancer, and provide novel validated DNA methylation markers associated with CIMP. Additional aspects provide novel methods and compositions for: determining CIMP status in colorectal cancers, determining the relationship between CIMP status and other molecular features of the cancers (e.g., BRAF mutation, KRAS mutation, and MSI status); determining the relationship between CIMP status and other variables (e.g., age, sex, tumor location, family history, race, country of origin, tumor characteristics (including, tumor type, tumor grade, invasive margin characteristics, lymphocyte infiltration characteristics, direct spread, lymph node spread, venous spread, and type of residual adjacent polyp, if present)); and determining, between subgroups defined by CIMP status and BRAF mutations, effects of selected risk factors (e.g.

Abstract: Particular aspects confirm the existence of a CpG island methylator phenotype (CIMP) in colorectal cancer, and provide novel validated DNA methylation markers associated with CIMP. Additional aspects provide novel methods and compositions for: determining CIMP status in colorectal cancers, determining the relationship between CIMP status and other molecular features of the cancers (e.g., BRAF mutation, KRAS mutation and MSI status); determining the relationship between CIMP status and other variables (e.g., age, sex, tumor location, family history, race, country of origin, tumor characteristics (including, tumor type, tumor grade, invasive margin characteristics, lymphocyte infiltration characteristics, direct spread, lymph node spread, venous spread and type of residual adjacent polyp, if present)); and determining, between subgroups defined by CIMP status and BRAF mutations, effects of selected risk factors (e.g.

Abstract: Particular aspects confirm the existence of a CpG island methylator phenotype (CIMP) in colorectal cancer, and provide novel validated DNA methylation markers associated with CIMP. Additional aspects provide novel methods and compositions for: determining CIMP status in colorectal cancers, determining the relationship between CIMP status and other molecular features of the cancers (e.g., BRAF mutation, KRAS mutation and MSI status); determining the relationship between CIMP status and other variables (e.g., age, sex, tumor location, family history, race, country of origin, tumor characteristics (including, tumor type, tumor grade, invasive margin characteristics, lymphocyte infiltration characteristics, direct spread, lymph node spread, venous spread and type of residual adjacent polyp, if present)); and determining, between subgroups defined by CIMP status and BRAF mutations, effects of selected risk factors (e.g.

Abstract: Preferred aspects provide novel high-throughput, sensitive methods (e.g., real-time PCR-based (MethyLight™) reactions) for detection and/or measurement of global genomic 5-methylcytosine content, based on measurement of DNA methylation of Alu, LINE-1 repetitive sequences, and the chromosome 1 centromeric satellite alpha and juxtacentromeric satellite 2 repeat sequences. Additional aspects provide sensitive methods for determining the amount of a DNA (e.g., in formalin-fixed, paraffin-embedded tissues). Combined (mean) use of Alu and Sat2 repeat methylation measurements provides for a surprisingly close correlation with global genomic 5-methylcytosine content measurements obtained by HPLC. Methylation of Alu repeats was determined to be closely associated with HPLC-based global methylation levels, as was methylation of satellite 2 and LINE-1 global genomic 5-methylcytosine content.

Abstract: Particular aspects confirm the existence of a CpG island methylator phenotype (CIMP) in colorectal cancer, and provide novel validated DNA methylation markers associated with CIMP. Additional aspects provide novel methods and compositions for: determining CIMP status in colorectal cancers, determining the relationship between CIMP status and other molecular features of the cancers (e.g., BRAF mutation, KRAS mutation and MSI status); determining the relationship between CIMP status and other variables (e.g., age, sex, tumor location, family history, race, country of origin, tumor characteristics (including, tumor type, tumor grade, invasive margin characteristics, lymphocyte infiltration characteristics, direct spread, lymph node spread, venous spread and type of residual adjacent polyp, if present)); and determining, between subgroups defined by CIMP status and BRAF mutations, effects of selected risk factors (e.g.