Table 3.

Reports of Race/Ethnic Differences in Tumor DNA Methylation Patterns

Cancer type	Observation	Reference
Prostate cancer	CpG hypermethylation of the GSTP1 promoter is more prevalent in prostate tumors of AA men than EA or Asian men.	86
	Globally higher DNA methylation in AA prostate tumors when compared with EA tumors in a genome-wide DNA methylation analysis.	87
Breast cancer	Prevalence of DNA methylation–defined tumor subtypes is different between AA and EA patients. Using a genome-wide DNA methylation analysis, the authors identified a poor survival tumor subtype with distinct DNA methylation, high tissue 2-hydroxyglutarate levels, and heightened occurrence in AA patients.	31
	Greater DNA methylation differences in ER-negative than ER-positive breast cancer, comparing AA with EA women in a genome-wide DNA methylation analysis. Globally, the number of differentially methylated CpG sites was low.	88
	Few differences in promoter methylation between AA and EA breast cancer patients in the tumors and in peripheral blood monocytes of these patients. More methylation differences in ER-negative tumors.	89
	In ER-negative breast cancer, AA patients had higher DNA methylation in four gene promoters of a five-gene panel when compared with EA patients. Differences were only observed among women with early-onset disease. No racial differences in ER-positive breast cancer.	90

AA, African-American; EA, European-American; ER, estrogen receptor.