The role of longitudinal cohort studies in epigenetic epidemiology: challenges and opportunities

Table 2 Nested case-control epigenetic studies in longitudinal cohorts: a summary of recent literature (2010 to 2012)

Cohort	DNA analysis time points	Tissue	Form of DNA methylation analysis	Loci	Exposure (if applicable)	Outcome (if applicable)	n	References
EPIC & Breakthrough Generations Study & KConFab	1	Peripheral blood	Pyrosequencing	ATM, LINE-1		Breast cancer	1,381	[112]
EPIC-Lung	1	Peripheral blood	Pyrosequencing	CDKN2A RASSF1A, GSTP1, MTHFR, MGMT	B vitamins, smoking	Lung cancer	93	[18]
EPIC-Norfolk	1	Tumor tissue	Pyrosequencing	MLH1		Colorectal cancer	185	[21]
EPIC-EURGAST	1	Tumor tissue	Pyrosequencing	CHRNA3, DOK1, MGMT, RASSF1A, p14ARF, CDH1, MLH1, ALDH2, GNMT, MTHFR		Gastric cancer	162	[22]
Iowa Women's Health Study	1	Tumor tissue	MethyLight	CpG island methylator phenotype	Smoking	Colorectal cancer	555	[23]
Netherlands Cohort Study	1	Tumor tissue	Methylation specific PCR	CACNA1G, IGF2, NEUROG1, RUNX3, SOCS1	Body size and physical activity	Colorectal cancer	734	[113]
New York University Women's Health Study	1	Peripheral blood	Methylation specific PCR	RASSF1A, GSTP1, APC, RARβ2		Breast cancer	200	[19]
Northern Sweden Health and Disease Study	1	Tumor tissue	MethyLight	CpG island methylator phenotype	B vitamins	Colorectal cancer	570	[24]
Nurse's Health Study	1	Tumor tissue	MethyLight	CACNA1G, CDKN2A, CRABP1, IGF2, MLH1, NEUROG1, RUNX3, SOCS1CHFR, HIC1, IGFBP3, MGMT, MINT-1, MINT-31, p14, WRN	B vitamins and alcohol	Colorectal cancer	761	[25]
Shanghai Women's Health Study	1	Peripheral blood	Pyrosequencing	Alu, LINE-1		Gastric cancer	576	[20]

Search strategy: a literature search retrieved >350 publications published between 1 January 2010 and 13 April 2012. Nested case-control studies within established longitudinal cohort studies are included. There are many further examples in which DNA methylation has been analyzed in a case-control study design, cross-sectional study or randomized controlled trial that includes some element of data collection over time (often retrospective), but these have not been included in the tables presented.

ISSN: 1474-760X