Table 2.

Study population and Characteristics of Infecting H. pylori Strains

Variables	Low risk for Gastric Cancer n=45	High risk for Gastric Cancer n=41	Two-tailed p-value *
Age in years, mean (SD)	47.5(6.0)	48.9(5.3)	0.257
cagA assessment by PCR, n(%)
Uninfected	7(15.6)	2(4.9)	0.209
Negative	6(13.3)	4(9.7)
Positive	32(71.1)	35(85.4)
H. pylori genotypes, n(%)
Uninfected	7(15.6)	2(4.9)	0.079
cagA positive, vacA s1m1**	29(64.4)	35(85.4)
Other genotypes	9 (20.0)	4 (9.7)
H. pylori genotypes, n(%)
Uninfected	7(15.6)	2(4.9)	0.128
cagA negative	6(13.3)	4(9.7)
cagA positive, 3 EPIYAs	25(55.6)	21(51.2)
cagA positive, >3 EPIYAs	7(15.5)	14(34.2)
H. pylori genotypes, n(%)
uninfected	7(15.6)	2(4.9)	0.076
cagA positive, (3 EPIYAs), vacA s1m1*	7(15.6)	14(34.2)
cagA positive (>3 EPIYAs) vacA s1m1*	22(48.8)	21(51.2)
other genotypes	9(20.0)	4(9.7)
Histopathological diagnosis§ , n(%)
Normal/NAG	27(61.4)	13(31.7)	0.021
MAG	6(13.6)	8(19.5)
IM/Dysplasia	11(25.0)	20(48.8)
% methylation, median (interquartile range)
RPRM	14(7)	21(7.5)	<0.001
APC	25(8)	23(9)	0.9158
MGMT	54(12)	58(11)	0.3788
TWIST1	8 (2)	10(4)	<0.001
Mathematically transformed values of % methylation, mean (SD)
RPRM (logarithm)	2.6(0.4)	3.0(0.3)	<0.001
APC (logarithm)	3.2(0.3)	3.2(0.2)	0.9460
MGMT(square-root)	3160(848.4)	3369(906.6)	0.2869
TWIST1(inverse)	0.10 (0.03)	0.13 (0.03)	<0.001

Abbreviations: SD= standard deviation; NAG: non-atrophic gastritis; MAG: multifocal atrophic gastritis; IM: intestinal metaplasia.

^*p-value from χ2, Fisher's exact, t test or Wilcoxon/Mann-Whitney test as appropriate.

^**This category includes a subject with a strain of H. pylori that was cagA positive and vacA s1, but which repeatedly failed PCR for vacA m.

^§A subject with gastritis in which we could not assess atrophy was excluded from this analysis.