Table 2. Baseline patient characteristics according to RAS/BRAF mutational status.
|
RAS/BRAF
wild |
RAS
mut |
BRAFV600E
mut |
BRAFnon-V600E
mut |
|||||
|---|---|---|---|---|---|---|---|---|
| (n=94) |
(n=40) |
(n=9) |
(n=7) |
|||||
| No | % | No | % | No | % | No | % | |
|
Age, years | ||||||||
| Median | 64 | 63 | 64 | 63 | ||||
| Range | 28–85 |
35–79 |
33–73 |
48–74 |
||||
|
Gender | ||||||||
| Male | 64 | 68.1 | 18 | 45 | 4 | 44.4 | 1 | 14.3 |
| Female | 30 | 31.9 | 22 | 55 | 5 | 55.6 | 6 | 85.7 |
|
ECOG PS | ||||||||
| 0 | 53 | 56.4 | 22 | 55 | 3 | 33.3 | 3 | 42.9 |
| 1 | 38 | 40.4 | 17 | 42.5 | 6 | 66.7 | 4 | 57.1 |
| 2 | 3 | 3.2 | 1 | 2.5 | 0 | 0 | 0 | 0 |
|
Histologya | ||||||||
| Well | 17 | 18.1 | 11 | 27.5 | 1 | 11.1 | 1 | 14.3 |
| Moderate | 62 | 66 | 23 | 57.5 | 6 | 66.7 | 5 | 71.4 |
| Poor | 11 | 11.7 | 5 | 12.5 | 1 | 11.1 | 1 | 14.3 |
| Others | 4 | 4.3 | 1 | 2.5 | 1 | 11.1 | 0 | 0 |
|
Primary tumour siteb | ||||||||
| Right-sided colon | 13 | 13.8 | 11 | 27.5 | 4 | 44.4 | 4 | 57.1 |
| Left-sided colon or rectum | 81 | 86.2 | 29 | 72.5 | 5 | 55.6 | 3 | 42.9 |
|
Resection of primary tumour | ||||||||
| 77 | 81.9 | 35 | 87.5 | 8 | 88.9 | 7 | 100 | |
|
Time to metastases | ||||||||
| Synchronous | 50 | 53.2 | 20 | 50 | 4 | 44.4 | 1 | 14.3 |
| Metachronous | 44 | 46.8 | 20 | 50 | 5 | 55.6 | 6 | 85.7 |
|
Number of metastases | ||||||||
| 1 | 33 | 35.1 | 10 | 25 | 5 | 55.6 | 0 | 0 |
| >1 | 61 | 64.9 | 30 | 75 | 4 | 44.4 | 7 | 100 |
|
Metastatic site | ||||||||
| Liver | 61 | 64.9 | 25 | 62.5 | 4 | 44.4 | 4 | 57.1 |
| Lung | 49 | 52.1 | 27 | 67.5 | 3 | 33.3 | 6 | 85.7 |
| Peritoneum | 20 | 21.3 | 9 | 22.5 | 3 | 33.3 | 2 | 28.6 |
| Lymph node | 37 | 39.4 | 11 | 27.5 | 1 | 11.1 | 5 | 71.4 |
|
Reason of discontinuation for each cytotoxic agent as prior treatment | ||||||||
| Fluoropyrimidine | ||||||||
| Failure | 94 | 100 | 40 | 100 | 9 | 100 | 7 | 100 |
| Intolerance | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Oxaliplatin | ||||||||
| Failure | 83 | 88.3 | 38 | 95 | 9 | 100 | 5 | 71.4 |
| Intolerance | 11 | 11.7 | 2 | 5 | 0 | 0 | 2 | 28.6 |
| Irinotecan | ||||||||
| Failure | 94 | 100 | 40 | 100 | 9 | 100 | 7 | 100 |
| Intolerance | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
|
Prior Bevacizumab | ||||||||
| 74 | 78.7 | 33 | 82.5 | 8 | 88.9 | 7 | 100 | |
|
Anti-EGFR antibody treatment | ||||||||
| Cetuximab | 66 | 70.2 | 29 | 72.5 | 6 | 66.7 | 5 | 71.4 |
| Panitumumab | 28 | 29.8 | 11 | 27.5 | 3 | 33.3 | 2 | 28.6 |
|
Combine use of Irinotecan | ||||||||
| Yes | 69 | 73.4 | 35 | 87.5 | 8 | 88.9 | 4 | 57.1 |
| No | 25 | 26.6 | 5 | 12.5 | 1 | 11.1 | 3 | 42.9 |
Abbreviations: ECOG=Eastern Cooperative Oncology Group; FP=fluoropyrimidine; mut=mutant; poor=poorly differentiated; well=well differentiated; moderate, moderately differentiated; wild=wild-type.
Wild-type RAS/BRAF was defined as all wild-type sequence with RAS, BRAFV600E, and BRAFnon-V600E.
a
Defined according to Japanese Classification (ref: JSCCR, Japanese Classification of Colorectal Carcinoma, 2nd English Ed).
b
Right-sided tumours were defined as those arising anywhere from the caecum to the transverse colon, and left-sided tumours were defined as those arising anywhere from the splenic flexure to the rectosigmoid junction.