Table 1.
Baseline Demographic and Clinical Characteristics of the study population and comparison of characteristics according to RAS mutational status.*
| Characteristic | Overall study population (n=184) |
RAS mutational status |
p value | ||
|---|---|---|---|---|---|
| Mutant (n=38) |
Wild-type (n=146) |
||||
| Age, years | |||||
| Median | 58 | 58 | 57 | .473 | |
| Range | 25–84 | 33-81 | 25-84 | ||
|
| |||||
| Sex | |||||
| Male | 107 | (58) | 18 (47) | 89 (61) | .130 |
| Female | 77 | (42) | 20 (53) | 57 (39) | |
|
| |||||
| Primary tumor location | |||||
| Rectum | 37 | (20) | 6(16) | 31 (21) | .476 |
| Colon | 147 | (80) | 32 (84) | 115 (79) | |
|
| |||||
| Primary tumor nodal status | |||||
| Negative | 52 | (28) | 10 (26) | 42 (29) | .765 |
| Positive | 132 | (72) | 28 (74) | 104 (71) | |
|
| |||||
| Extrahepatic metastases | |||||
| Yes | 16 | (9) | 4(11) | 12(8) | .653 |
| No | 168 | (91) | 36 (89) | 134 (92) | |
|
| |||||
| DFI, years | |||||
| <1 | 122 | (66) | 23 (61) | 99 (68) | .398 |
| ≥1 | 62 | (34) | 15 (39) | 47 (32) | |
|
| |||||
| Multiple CLM | |||||
| Yes | 62 | (34) | 14 (37) | 48 (33) | .645 |
| No | 122 | (66) | 24 (63) | 98 (67) | |
|
| |||||
| CLM size at surgery, cm | |||||
| Median | 2.5 | 2.5 | 2.5 | .713 | |
| Range | 1–15 | 1.2-13.5 | 1-15 | ||
|
| |||||
| Fluorouracil-based chemotherapy regimen |
|||||
| Oxaliplatin | 137 | (74) | 25 (66) | 112 (77) | .209 |
| Irinotecan | 47 | (36) | 13 (34) | 34 (23) | |
|
| |||||
| Number of preoperative chemotherapy cycles |
|||||
| Median | 6 | 8 | 6 | .597 | |
| Range | 5–18 | 6-18 | 5-18 | ||
|
| |||||
| Morphologic response | |||||
| Optimal | 52 | (28) | 4(11) | 48 (33) | .006 |
| Suboptmal | 132 | (72) | 34 (89) | 96 (67) | |
|
| |||||
| Pathologic response | |||||
| Major | 100 | (54) | 14 (37) | 86 (59) | .015 |
| Minor | 84 | (46) | 24 (63) | 60 (41) | |
|
| |||||
| Portal vein embolization | 39 | (21) | 10 (26) | 29 (20) | .363 |
|
| |||||
| Hepatectomy | |||||
| Major resection | 123 | (67) | 25 (66) | 98 (67) | .876 |
| Minor resection | 61 | (33) | 13 (34) | 48 (33) | |
|
| |||||
| Operating time, min | |||||
| Median | 231 | 235 | 230 | .880 | |
| Range | 55–535 | 62-460 | 55-535 | ||
|
| |||||
| Intraoperative transfusion | 14 | (8) | 3(8) | 11(8) | .915 |
|
| |||||
| Surgical margin | |||||
| Positive | 23 | (12) | 7(18) | 16(11) | .215 |
| Negative | 161 | (88) | 31 (82) | 130 (89) | |
|
| |||||
| Morbidity | |||||
| None | 100 | (54) | 19 (50) | 81 (55) | .168 |
| Minor | 51 | (28) | 8(21) | 43 (30) | |
| Major | 33 | (18) | 11 (29) | 22(15) | |
|
| |||||
| RAS mutational status | |||||
| Wild-type | 146 | (79) | |||
| Mutant | 38 | (21) | |||
| KRAS | 32/38 | (84) | |||
| Codon 12 | 28/32 | (88) | |||
| Codon 13 | 2/32 | (6) | |||
| Codon 61 | 2/32 | (6) | - | - | - |
| Codon 146 | 0/32 | (0) | |||
| NRAS | 6/38 | (16) | |||
| Codon 12 | 3/6 | (50) | |||
| Codon 13 | 0/6 | (0) | |||
| Codon 61 | 3/6 | (50) | |||
| Codon 146 | 0/6 | (0) | |||
Abbreviations: DFI, disease-free interval; CLM, colorectal liver metastases.
*
Values in table are number of patients (%) unless otherwise specified.