Table 1.
IGF2 differentially methylated region 0 hypomethylation in serrated lesions and non-serrated adenomas n (%)
| Clinicopathological feature | Total n |
IGF2 DMR0 methylation (quartile) |
P value | |||
| Q1 (≥ 74.5) | Q2 (62.6-74.4) | Q3 (49.6-62.5) | Q4 (≤ 49.5) | |||
| All cases | 536 | 134 | 130 | 131 | 141 | |
| Sex | ||||||
| Male | 326 (61) | 78 (58) | 80 (62) | 92 (70) | 76 (54) | 0.041 |
| Female | 210 (39) | 56 (42) | 50 (38) | 39 (30) | 65 (46) | |
| Age (mean ± SD) | 61.5 ± 12.2 | 59.9 ± 12.3 | 60.8 ± 12.0 | 63.1 ± 11.6 | 62.3 ± 13.0 | 0.150 |
| Tumor size (mm) (mean ± SD) | 14.3 ± 11.4 | 9.9 ± 4.0 | 13.4 ± 7.4 | 14.7 ± 11.1 | 19.1 ± 17.6 | < 0.0001 |
| Tumor location | ||||||
| Rectum | 70 (13) | 11 (8.5) | 14 (11) | 18 (14) | 27 (20) | 0.061 |
| Distal colon | 161 (31) | 35 (27) | 43 (33) | 37 (29) | 46 (33) | |
| Proximal colon | 296 (56) | 84 (65) | 72 (56) | 75 (58) | 65 (47) | |
| Histological type | ||||||
| Hyperplastic polyp (HP) | 115 (21) | 33 (25) | 25 (19) | 23 (18) | 34 (24) | < 0.0001 |
| Sessile serrated adenoma (SSA) without cytological dysplasia | 120 (22) | 60 (45) | 39 (30) | 15 (11) | 6 (4.3) | |
| SSA with cytological dysplasia | 10 (1.9) | 1 (0.8) | 3 (2.3) | 6 (4.6) | 0 (0) | |
| Traditional serrated adenoma (TSA) without high-grade dysplasia (HGD) | 91 (17) | 22 (16) | 21 (16) | 23 (18) | 25 (18) | |
| TSA with HGD | 15 (2.8) | 2 (1.5) | 2 (1.5) | 2 (1.5) | 9 (6.4) | |
| Non-serrated adenoma (tubular or tubulovillous adenoma) without HGD | 80 (15) | 11 (8.2) | 17 (13) | 32 (24) | 20 (14) | |
| Non-serrated adenoma with HGD | 105 (20) | 5 (3.7) | 23 (18) | 30 (23) | 47 (33) | |
Percentage indicates the proportion of patients of each histological type who met the criteria for a specific clinical or molecular feature. P values were calculated by analysis of variance for age and tumor size and by χ2 or Fisher’s exact test for all other variables. The P value for significance was adjusted by Bonferroni correction to 0.010 (= 0.05/5).