Table 1.
Association between p16 and MGMT methylation, K-ras mutations and clinicopathological features of colorectal cancer
| Methylation (%) | Mutations (%) | ||
| Variable | p16 (n = 46) | MGMT (n = 46) | K-ras (n = 84) |
| Gender | |||
| Female | 9/15 (60.0) | 7/15 (46.7) | 15/23 (65.2)a |
| Male | 15/31 (48.4) | 13/31 (41.9) | 22/61 (36.1) |
| Dukes’ stage | |||
| A | 5/9 (55.5) | 5/9 (55.5) | 8/21 (38.1) |
| B | 7/10 (70.0) | 4/10 (40.0) | 12/24 (50.0) |
| C | 8/15 (53.3) | 8/15 (53.3) | 17/39 (43.6)4 |
| D | 4/12 (33.3) | 3/12 (25.0) | |
| Differentiation | |||
| Poor | 15/25 (60.0) | 10/25 (40.0) | 18/44 (40.9) |
| Moderate | 8/18 (44.4) | 10/18 (55.5) | 16/26 (61.5) |
| Well | 1/3 (33.3) | 0/3 (0) | 3/14 (21.4) |
| Macrosopic type2 | |||
| Polypoid | 11/23 (47.8) | 14/23 (60.7)a | 25/48 (52.1) |
| Flat | 13/23 (56.5) | 6/23 (26.1) | 12/35 (34.3) |
| Histological type2 | |||
| Mucinous | 8/19 (42.1) | 6/19 (31.6) | 16/34 (47.1) |
| Tubular | 16/27 (59.3) | 14/27 (51.8) | 21/49 (42.8) |
| Location2 | |||
| Proximal | 3/3 (100) | 1/3 (33.3) | 5/9 (55.5) |
| Distal | 21/43 (48.8) | 19/43 (44.2) | 32/74 (43.2) |
| Progression (2 yr)1,3 | |||
| Metastasis or/and death | 11/25 (44.0) | 9/25 (36.0) | 29/44 (65.9)b |
| Without progression | 12/19 (63.1) | 11/19 (57.9) | 7/37 (18.9) |
Complete clinicopathological data were missing on one sample of colorectal cancer, and it was only included in analysis of genetic alterations;
a
P < 0.05;
b
P < 0.001 (all P values were revealed by χ2-test ); Data are missing on two1 subjects for p16 and MGMT methylation status analysis, and on one2 and three3 subjects for K-ras mutation analysis, respectively.
4
Data for C and D Dukes’ stages are considered together for K-ras mutation analysis.