Table 1.
Clinicopathological and molecular characteristics of patients and tumors by CpG island methylator phenotype (CIMP) status
| Characteristic | Total | CIMP− | CIMP+ | P * |
|---|---|---|---|---|
| No. of patients | 99 | 72 (72.7%) | 27 (27.3%) | |
| Sex | 1.000 | |||
| Male | 55 (55.6%) | 40 (55.6%) | 15 (55.6%) | |
| Female | 44 (44.4%) | 32 (44.4%) | 12 (44.4%) | |
| Age at surgery | 0.247 | |||
| < 70 | 64 (64.6%) | 49 (68.1%) | 15 (55.6%) | |
| ≥70 | 35 (35.4%) | 23 (31.9%) | 12 (44.4%) | |
| Stage | 0.067† | |||
| I (T1–2 N0 M0) | 8 (8.1%) | 3 (4.2%) | 5 (18.5%) | |
| II (T3–4 N0 M0) | 21 (21.2%) | 18 (25.0%) | 3 (11.1%) | |
| III (anyT N1-2 M0) | 64 (64.6%) | 47 (65.3%) | 17 (63.0%) | |
| IV (anyT anyN M1) | 6 (6.1%) | 4 (5.6%) | 2 (7.4%) | |
| Tumor differentiation | 1.000 | |||
| Well/moderate | 55 (55.6%) | 40 (55.6%) | 15 (55.6%) | |
| Poor | 44 (44.4%) | 32 (44.4%) | 12 (44.4%) | |
| Extent of resection | 1.000† | |||
| R0 | 87 (87.9%) | 63 (87.5%) | 24 (88.9%) | |
| R1/R2 | 12 (12.1%) | 9 (12.5) | 3 (11.1%) | |
| Chemotherapy/radiotherapy | 0.448 | |||
| No | 38 (38.4%) | 26 (36.1%) | 12 (44.4%) | |
| Yes | 61 (61.6%) | 46 (63.9%) | 15 (55.6%) | |
| MSI status | 0.011 | |||
| MSS | 79 (79.8%) | 62 (86.1%) | 17 (63.0%) | |
| MSI | 20 (20.2%) | 10 (13.9%) | 10 (37.0%) | |
| KRAS | 0.114 | |||
| Wild-type | 67 (67.7%) | 52 (72.2%) | 15 (55.6%) | |
| Mutated | 32 (32.3%) | 20 (27.8%) | 12 (44.4%) | |
| MLH1 methylation | < 0.001† | |||
| U | 85 (85.9%) | 70 (97.2%) | 15 (55.6%) | |
| M | 14 (14.1%) | 2 (2.8%) | 12 (44.4%) |
NOTE:
*
CIMP− versus CIMP+, χ2 test unless indicated otherwise;
†
Fisher’s exact test.
Abbreviations: CIMP, CpG island methylator phenotype; MSS, microsatellite stable; MSI, microsatellite instability; U, unmethylated; M, methylated.