Table I.
Comparison of neoplasm characteristics between the two groups.
| Variables | iFOBT-negative (513 lesions) | iFOBT-positive (410 lesions) | P-value |
|---|---|---|---|
| Non-advanced neoplasia | 470 | 338 | |
| Average size, mm (mean ± SD) | 3.68±1.44 | 3.89±1.58 | 0.05 |
| Location, proximal/total (%) | 260/470 (55.3) | 191/338 (56.5) | 0.737 |
| Shapea, protruding/total (%) | 198/470 (42.1) | 190/338 (56.2) | <0.001 |
| Advanced neoplasia | 43 | 72 | |
| Average size, mm (mean ± SD) | 11.8±10.3 | 14.8±11.6 | 0.080 |
| Location, proximal/total (%) | 20/43 (46.5) | 28/72 (38.9) | 0.423 |
| Shapea, protruding/total (%) | 20/42a (47.6) | 43/68a (63.2) | 0.108 |
| Advanced adenoma | 42 | 61 | |
| Average size, mm (mean ± SD) | 10.5±6.24 | 12.3±7.39 | 0.197 |
| Location, proximal/total (%) | 19/42 (45.2) | 25/61 (41.0) | 0.668 |
| Shape, protruding/total (%) | 20/42 (47.6) | 41/61 (68.3) | <0.05 |
| Colorectal cancer | 1 | 11 | |
| Average size (mm) | 65.0 | 28.6±19.5 | |
| Location, proximal/total (%) | 1/1 (100) | 3/11 (27.3) | 0.333 |
| Shapea, protruding/total (%) | (advanced cancer) | 2/7a (18.2) | |
| Combined (total neoplasia) | 513 | 410 | |
| Average size, mm (mean ± SD) | 4.36±3.96 | 5.8±6.54 | <0.001 |
| Location, proximal/total (%) | 280/513 (54.6) | 219/410 (53.4) | 0.724 |
| Shapea, protruding/total (%) | 218/512a (42.6) | 233/406a (57.4) | <0.001 |
| Rate of non-advanced neoplasia | 470/513 (91.6) | 338/410 (82.4) | <0.001 |
| Rate of advanced neoplasia | 43/513 (8.4) | 72/410 (17.6) | <0.001 |
| Rate of advanced adenoma | 42/513 (8.2) | 61/410 (14.9) | <0.01 |
| Rate of colorectal cancer | 1/513 (0.19) | 11/410 (2.7) | <0.01 |
a
Cases of advanced colorectal cancer were excluded. iFOBT, immunochemical faecal occult blood test; standard deviation.