Table 2.
Hypermethylation of SFRP2 in tissue and stool specimens taken from the same patients with colorectal cancer, adenoma, polyp and normal controls
| Characteristics | Case (n) | Tissue M1 (%) | χ2 | P | Fecal M2 (%) | χ2 | P | Sensitivity M2/n | Specificity |
| Colorectal Cancer | 69 | 63 (91.3) | 75.3261 | 0.0001 | 60 (87.0) | 57.5881 | 0.0001 | 87.00% | |
| Age | |||||||||
| < 50 | 20 | 17 (85.0) | 1.410 | 0.235 | 16 (80.0) | 1.202 | 0.273 | ||
| ≥ 50 | 49 | 46 (93.9) | 44 (89.8) | ||||||
| Sex | |||||||||
| Male | 37 | 34 (91.9) | 0.035 | 0.852 | 32 (86.5) | 0.016 | 0.901 | ||
| Female | 32 | 29 (90.6) | 28 (87.5) | ||||||
| TNM stage | |||||||||
| I/II | 30 | 27 (90.0) | 0.114 | 0.736 | 25 (83.3) | 0.614 | 0.433 | ||
| III/IV | 39 | 36 (92.3) | 35 (89.7) | ||||||
| Lymph node status | |||||||||
| Positive | 27 | 25 (92.6) | 0.093 | 0.761 | 24 (88.9) | 0.146 | 0.702 | ||
| Negative | 42 | 38 (90.5) | 36 (85.7) | ||||||
| Infiltration | |||||||||
| Mucosa underlayer | 21 | 18 (85.7) | 1.188 | 0.276 | 17 (81.0) | 0.959 | 0.327 | ||
| Muscular coat | 48 | 45 (93.8) | 43 (89.6) | ||||||
| Tumor site | |||||||||
| Rectum | 30 | 27 (90.0) | 0.306 | 0.858 | 27 (90.0) | 0.428 | 0.786 | ||
| Left hemicolon | 18 | 17 (94.4) | 15 (83.3) | ||||||
| Right hemicolon | 21 | 19 (90.5) | 18 (85.7) | ||||||
| Adenoma | 34 | 27 (79.4) | 27.5791 | 0.0001 | 21 (61.8) | 21.0161 | 0.0001 | 61.80% | |
| Tubular adenoma | 11 | 8 (72.7) | 0.518 | 0.772 | 6 (54.5) | 0.563 | 0.755 | ||
| Villous adenoma | 10 | 8 (80.0) | 6 (60.0) | ||||||
| Tubulovillous adenoma | 13 | 11 (84.6) | 9 (69.2) | ||||||
| Hyperplastic polyp | 26 | 14 (53.8) | 21.5381 | 0.0001 | 11 (42.3) | 9.9261 | 0.0021 | 42.30% | 76.80% |
| Normal control | 30 | 0 | 2 (6.7) |
M1: Hypermethylated SFRP2 in tissue; M2: Hypermethylated SFRP2 in stool.
Represents the value of χ2 and P vs normal controls. There were significant differences in prevalence of hypermethylated SFRP2 in tissue and stool between cancer and adenoma (χ2 = 2.921, P = 0.087 and χ2 = 8.606, P = 0.003, respectively) and between cancer and hyperplastic polyp (χ2 = 17.253, P < 0.001 and χ2 = 19.936, P < 0.001, respectively). However, a significant difference was observed in prevalence of hypermethylated SFRP2 between adenoma and hyperplastic polyp only in tissue (χ2 = 4.450, P = 0.035) but not in fecal specimens (χ2 = 2.241, P = 0.134).