Table 4. Association between primary tumor sidedness and clinicopathological characteristics in 49 patients with anti-EGFR therapy in addition to cytotoxic chemotherapy.
| Primary tumor sidedness | P-value | ||
|---|---|---|---|
| Variable | Right (n = 8) | Left (n = 41) | |
| Age (years) | |||
| < 65 | 4 | 27 | 0.443 |
| ≥ 65 | 4 | 14 | |
| Sex | |||
| Male | 4 | 27 | 0.443 |
| Female | 4 | 14 | |
| Tumor size (mm) | |||
| < 50 | 5 | 19 | 0.463 |
| ≥ 50 | 3 | 22 | |
| T category | |||
| T2, 3 | 4 | 18 | 0.999 |
| T4 | 4 | 23 | |
| Histopathological grading | |||
| G1, 2 | 3 | 32 | 0.033 |
| G3 | 5 | 9 | |
| Lymphatic invasion | |||
| Absence | 1 | 14 | 0.406 |
| Presence | 7 | 27 | |
| Venous invasion | |||
| Absence | 2 | 6 | 0.601 |
| Presence | 6 | 35 | |
| N category | |||
| N0 | 1 | 5 | 0.999 |
| N1, 2 | 7 | 36 | |
| M category | |||
| M0 | 1 | 1 | 0.421 |
| M1a | 4 | 23 | |
| M1b | 3 | 17 | |
| KRAS status | |||
| Wild-type | 7 | 39 | 0.421 |
| Mutant | 1 | 2 | |
| BRAF status | |||
| Wild-type | 5 | 38 | 0.047 |
| Mutant | 3 | 3 | |
| Alterations in TK receptors/RAS pathway/PI3K pathway excluding KRAS and BRAF mutations | |||
| Absence | 7 | 20 | 0.059 |
| Presence | 1 | 21 | |
| Alterations in TK receptors/RAS pathway/PI3K pathway | |||
| 0 | 3 | 15 | 0.492 |
| 1 | 5 | 20 | |
| 2 | 0 | 6 | |
| All wild-type | 3 | 15 | 0.999 |
| Mutant-type | 5 | 26 | |
| Anti-EGFR drug | |||
| Cetuximab | 2 | 9 | 0.999 |
| Panitumumab | 6 | 32 | |
| Anti-EGFR therapy | |||
| Initial therapy | 3 | 9 | 0.386 |
| Subsequent therapy | 5 | 32 | |
| Chemotherapy added to anti-EGFR therapy | |||
| Oxaliplatin-based | 3 | 7 | 0.195 |
| Irinotecan-based | 3 | 29 | |
| Anti-EGFR drug only | 2 | 5 | |