Table 3.

Frequency of methylation at a single CpG in each of six selected genes in mucosal tissue, tumor tissue, and fecal DNA collected from patients undergoing surgery for colorectal carcinoma

SiteGene locus
ESR1 (132)ESR1 (195)ESR1 (281)MGMT (48)HPP1 (108)p16 (100)APC (166)MLH1 (123)
Mucosa38.7 ± 1.129.9 ± 0.833.8 ± 1.11.3 ± 0.30.51 ± 0.2NDNDND
Tumor40.6 ± 1.034.0 ± 1.2*35.2 ± 1.34.0 ± 2.28.4 ± 1.20.06 ± 0.10.4 ± 0.4ND
Feces44.2 ± 1.3*33.6 ± 0.9*39.1 ± 1.4*14.1 ± 2.51.8 ± 1.02.1 ± 1.21.6 ± 0.50.7 ± 0.7
  • NOTE: Values are means and SEM of percentage values. ND, not determined.

  • * P < 0.05, fecal or tumor samples differed significantly from the normal mucosa.

  • P < 0.01, fecal or tumor samples differed significantly from the normal mucosa.