Table 1.
Clinicopathological features of patients with different MLH1 promoter methylation or BRAF mutation statuses.
| Characteristic | Positive MLH1 promoter methylation n = 89 (%) | Negative MLH1 promoter methylation n = 80 (%) | p | Mutant BRAF n = 29 (%) | Wild-type BRAF n = 140 (%) | p |
|---|---|---|---|---|---|---|
| Age at onset (y) | ||||||
| Median | 63 | 52 | 64 | 54 | ||
| Mean | 60.3 | 49.5 | <0.001 | 66.2 | 52.9 | <0.001 |
| SD | 13.2 | 11.8 | 9.8 | 13.2 | ||
| Proximal location | 63 (70.8) | 44 (55.0) | 0.033 | 27 (93.1) | 80 (57.1) | <0.001 |
| Poor differentiation | 39 (43.8) | 27 (33.8) | 0.180 | 16 (55.2) | 50 (35.7) | 0.051 |
| Mucinous component | 46 (51.7) | 33 (41.3) | 0.175 | 12 (41.4) | 67 (47.9) | 0.525 |
| Signet ring component | 2 (2.2) | 1 (1.3) | 0.624 | 1 (3.4) | 2 (1.4) | 1.000 |
| Signet ring+ Mucinous component | 5 (5.6) | 8 (10.0) | 0.286 | 2 (6.9) | 11 (7.9) | 1.000 |
| Synchronic CRC | 3 (3.4) | 8 (10.0) | 0.081 | 1 (3.4) | 10 (7.1) | 0.749 |
| Lynch-related tumor | 3 (3.4) | 6 (7.5) | 0.395 | 0 | 9 (6.4) | 0.343 |
| FDR or SDR with CRC | 12 (13.5) | 32 (40) | <0.001 | 0 | 44 (31.4) | <0.001 |
| FDR or SDR with CRC aged <50 y | 3 (3.4) | 17 (21.3) | <0.001 | 0 | 19 (13.6) | 0.075 |
| FDR with CRC | 9 (10.0) | 27 (33.8) | <0.001 | 0 | 35 (25.0) | 0.002 |
| FDR with CRC aged <50 y | 3 (3.4) | 14 (17.5) | 0.002 | 0 | 16 (11.4) | 0.118 |
| FDR or SDR with a LS-related tumor | 17 (18.9) | 14 (17.5) | 0.788 | 6 (20.7) | 25 (17.9) | 0.720 |
| FDR or SDR with a LS-related tumor aged <50 y | 4 (4.5) | 6 (7.5) | 0.617 | 1 (3.4) | 9 (6.4) | 0.852 |
| Fulfillment of revised Bethesda guidelines | 42 (47.8) | 69 (86.3) | <0.001 | 8 (27.6) | 103 (73.6) | <0.001 |
CRC: colorectal cancer, FDR: first-degree relative, defined as a patient's parent (father or mother), full sibling (brother or sister) or child, SDR: second-degree relative, defined as a patient`s uncle, aunt, nephew, niece, grandparent, grandchild, half-sibling, and double cousin who shared 25% of a person's genes.