Table 2

Geometric means (95% confidence intervals) of percentage methylation for selected genes in colonic normal and tumor tissues

CpG islandNormal tissue (n = 62)Tumorous tissue (n = 62)Pa
APC 3.3 (2.4, 4.4)7.4 (5.3, 10.1)<0.0001
CDKN2A promoter2.3 (1.7, 3.0)3.8 (2.9, 5.0)<0.0001
CDKN2A exon 226.4 (24.0, 29.0)31.4 (28.8, 34.1)0.0002
ESR1 7.0 (4.8, 10.2)28.1 (22.8, 34.5)<0.0001
MLH1 (All)9.7 (7.5, 12.3)9.1 (7.0, 11.7)0.09
MLH1 (MSI−)9.5 (7.1, 12.6)7.5 (5.8, 9.6)0.63
MLH1 (MSI+)10.2 (6.2, 16.4)16.7 (9.0, 30.2)0.04
  • a Ps for ratio differences in methylation percentages between normal and tumor colonic tissues were based on the Wilcoxon signed rank test.