Table 1.

Methylation methods and methylation rate in each GI cancer.

Year	Sample size	Methylated rate	Detection method	APC promoter	Prognostic prediction	Nation	Reference
Esophagus cancer
2000	84	76%	MSP	1A		USA	(39)
2006	27	92%	MS-SSCA; MS-DBA	1A		Switzerland	(42)
2004	50	78%	MSP	1A		Germany	(43)
2009	45	44.4%	MSP	1A		Iran	(44)
2009	59	45.8%	MSP	1A	wp	Germany	(45)
Gastric cancer
2015	73	83.6%	MSP	1A		Greece	(46)
2018	24	83.3%	MSP	1A		China	(47)
2009	NA	NA	MSP	1A		Japan	(30)
2011	92	60%	MSP	1A		China	(48)
2016	40	82.5%	MSP	1A		Japan	(31, 49)
Colorectal cancer
2013	52s/49v	53.8%s, 44.9%v	MSP	1A		Sweden & Vietnam	(50, 51)
1997	NA	NA	BSP	1A		Finland	(52)
2004	118	28%	MSP	1A		Canada & USA	(18)
2008	31	45%	MSP	1A		UK	(53)
2018	36nsm/47fsm/13asm	19%nsm, 26%fsm, 62%asm	IIHBM	1A		Germany	(54)
2012	112	11.9%	MSP	1A		Iran	(55)
2000	108	18%	MSP	1A		Spain and USA	(51)
2016	155	42%	MSP	1A	wp	Greece	(56)
2013	111	27%	Pyrosequencing	1A	wp	Sweden	(57)
Liver cancer
2010	30	81.25%	IGMA	1A	wp	France	(58)
2014	57	64.91%	methylight	–	wp	China	(59)
2003	60	81.7%	MSP	1A		Korea	(60)
2015	221	78%	IIHBM	–		Italy & Spain	(61)
2011	32	84%	BSP	1A		China & USA	(62)
2013	23	100%ss	MSP	1A		Japan	(63)
Pancreatic cancer
2020	NA	NA	IMBA	1A		Israel	(37)
2016	85	71%	MS-MCA	1A		Spain	(64)
2006	58	58.6%	MSP	1A		Japan	(65)

wp, worse prognosis; MSP, methylation-specific PCR; MS-SSCA, Methylation-sensitive single-strand conformation analysis; MS-DBA, Methylation-sensitive dot-blot assay; S, Swedish patients; V, Vietnamese patients; nsm, never smoking patients; fsm, former smoking patients; asm, active smoking patients; IIHBM, Illumina Infinium HumanMethylation450 BeadChip microarrays; NA, not available; BSP, Bisulfite sequencing PCR; IGMA, Illumina GoldenGate methylation assay; SS, samples from serum; IMBA, Infinium MethylationEPIC BeadChip Array; MS-MCA, methylation specific-melting curve analysis.