Table 1.
Efficacy outcomes according to RAS status and primary tumor location.
| RAS assessble (n=247) |
RAS wild-type (n=216) |
RAS mutant (n=31) | RAS wild-type/ Left-sided (n=158) |
RAS wild-type/ Right-sided (n=58) |
||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Cetuximab plus chemotherapy (n=117) |
Chemotherapy alone (n=130) |
Cetuximab plus chemotherapy (n=103) |
Chemotherapy alone (n=113) |
Cetuximab plus chemotherapy (n=14) |
Chemotherapy alone (n=17) |
Cetuximab plus chemotherapy (n=74) |
Chemotherapy alone (n=84) |
Cetuximab plus chemotherapy (n=29) |
Chemotherapy alone (n=29) |
|
| Overall response | ||||||||||
| CR | 2 (1.7%) | 1 (0.8%) | 2 (1.9%) | 1 (0.9%) | 0 (0) | 0 (0) | 2 (2.7%) | 1 (1.2%) | 0 (0) | 0 (0) |
| PR | 67 (57.3%) | 38 (29.2%) | 64 (62.1%) | 32 (28.3%) | 3 (21.4%) | 6 (35.2%) | 49 (66.2%) | 24 (28.6%) | 15 (58.6%) | 8 (27.6%) |
| SD | 30 (25.6%) | 47 (36.1%) | 24 (23.3%) | 42 (37.1%) | 6 (42.9%) | 6 (35.2%) | 16 (21.6%) | 32 (38.1%) | 8 (27.6%) | 10 (34.5%) |
| PD | 17 (14.5%) | 40 (30.8%) | 12 (11.7%) | 35 (31.0%) | 5 (35.7%) | 4 (23.5%) | 8 (10.8%) | 26 (31.0%) | 4 (13.7%) | 9 (31.0%) |
| Not assessable∗ | 1 (0.9%) | 4 (3.1%) | 1 (1.0%) | 3 (2.7%) | 0 (0) | 1 (5.9%) | 1 (1.4%) | 1 (1.2%) | 0 (0) | 2 (6.9%) |
|
| ||||||||||
| ORR, % | 59.0 | 30.0 | 64.1 | 29.2 | 21.4 | 35.3 | 68.9 | 29.8 | 51.7 | 27.6 |
| OR | 3.35 | 4.32 | 0.50 | 5.23 | 2.81 | |||||
| 95% CI | 1.98-5.67 | 2.44-7.66 | 0.10-2.52 | 2.65-10.32 | 0.94-8.39 | |||||
| p (Chi-square or Fisher's) | <0.001 | <0.001 | 0.456 | <0.001 | 0.060 | |||||
| p for interaction test | 0.014 | 0.344 | ||||||||
|
| ||||||||||
| Radical resection rate of LM, % | 28.2 | 10.0 | 31.1 | 9.7 | 7.3 | 11.8 | 35.1 | 10.7 | 20.7 | 6.9 |
| OR | 3.54 | 4.18 | 0.58 | 4.51 | 3.52 | |||||
| 95% CI | 176-7.12 | 1.98-8.84 | 0.05-7.12 | 1.95-10.46 | 0.65-19.17 | |||||
| p (Chi-square or Fisher's) | <0.001 | <0.001 | 0.835 | <0.001 | 0.128 | |||||
|
| ||||||||||
| PFS, months | ||||||||||
| Median | 9.8 | 5.7 | 10.2 | 5.5 | 6.0 | 8.9 | 11.3 | 5.6 | 8.1 | 5.1 |
| 95%CI | 8.9-11.1 | 4.1-5.9 | 9.3-10.7 | 4.1-5.9 | 1.3-6.8 | 5.0-9.0 | 9.9-12.1 | 3.9-6.1 | 5.2-8.8 | 2.2-5.8 |
| HR | 0.61 | 0.52 | 1.63 | 0.46 | 0.67 | |||||
| 95%CI | 0.46-0.80 | 0.39-0.70 | 0.75-3.54 | 0.32-0.65 | 0.39-1.17 | |||||
| p (log-rank) | <0.001 | <0.001 | 0.166 | <0.001 | 0.127 | |||||
| p for interaction test | 0.003 | 0.183 | ||||||||
|
| ||||||||||
| OS, months | ||||||||||
| Median | 30.0 | 22.8 | 36.1 | 21.7 | 16.8 | 25.6 | 48.0 | 22.5 | 23.6 | 16.8 |
| 95%CI | 18.9-39.1 | 18.3-25.7 | 24.6-43.4 | 18.0-24.0 | 11.2-20.8 | 15.1-32.9 | - | 18.1-23.9 | 21.7-26.3 | 4.5-23.5 |
| HR | 0.55 | 0.46 | 1.94 | 0.27 | 0.66 | |||||
| 95%CI | 0.38-0.80 | 0.31-0.70 | 0.75-5.02 | 0.14-0.50 | 0.35-1.26 | |||||
| p (log-rank) | 0.001 | <0.001 | 0.146 | <0.001 | 0.200 | |||||
| p for interaction test | 0.006 | 0.036 | ||||||||
∗ 3 early deaths (less than 3 months) and 2 lost to follow-up before the first time evaluation by MDT.
CR, complete response; PR, partial response; SD, stable disease; PD, progressive disease; ORR, objective response rate; LM, liver metastases; PFS, progression free survival; OS, overall survival; HR, hazard ratio; OR, odds ratio;95% CI, 95% confidence interval. MDT, multidisciplinary team; NE, not evaluable.