Table 3.
Disease-free survival according to treatment arm and CEA level
| DFS | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| 3 y % (95% CI) | P-value for the interaction term between CEA (≤ 2.35, > 2.35) and Treatment Arm (LV5FU2, FOLFOX) | ||||||||
| All N | LV5FU2 arm N | FOLFOX arm N | LV5FU2 arm | FOLFOX arm | Absolute changed | Relative changee | HR for treatment effectc (95% CI) | ||
| Whole population | 899 | 448 | 451 | 84.7 (81.4–88.1) | 87.1 (84–90) | +2.4 | +2.8 | 0.11 | |
| CEA ≤2.35 | 664 | 333 | 331 | 88.2 (84.8–91.7) | 88.7 (85.4–92.2) | +0.5 | +0.6 | 1.07 (0.77–1.47) | |
| CEA >2.35 | 203 | 97 | 106 | 76 (67.9–85.1) | 81.1 (74–88.9) | +5.1 | +6.7 | 0.67 (0.41–1.11) | |
| High-riska population | 434 | 222 | 212 | 81.3 (76.2–86.6) | 86.3 (81.7–91) | +5 | +6.1 | 0.09 | |
| High-risk - CEA ≤2.35 | 320 | 158 | 162 | 84 (78.4–89.9) | 86.3 (81.2–91.8) | +2.3 | +2.7 | 0.95 (0.62–1.45) | |
| High-risk - CEA >2.35 | 102 | 55 | 47 | 74 (63.2–86.7) | 87.2 (78.2–97.3 | +13.2 | +17.8 | 0.47 (0.23–0.97) | |
| Low-riskb population | 458 | 223 | 235 | 87.9 (83.7–92.3) | 88 (83.9–92.3) | +0.1 | +0.1 | 0.78 | |
| Low-risk - CEA ≤2.35 | 338 | 172 | 166 | 91.8 (87.8–96) | 91.5 (87.3–95.8) | −0.3 | −0.3 | 1.18 (0.71–1.95) | |
| Low-risk - CEA >2.35 | 100 | 42 | 58 | 78.6 (67.1–92) | 75.8 (65.6–87.7) | −2.8 | −3.6 | 0.99 (0.47–2.10) | |
Absolute difference at time X gives the difference between percentages observed in the two treatment arms at time X; the relative difference at time X gives the proportion of increase or decrease in survival rate of one arm relative to the other arm at time X
aT4, tumour perforation, or fewer than 10 lymph nodes examined
bT1–3 and no tumour perforation and 10 or more lymph nodes examined
cHR for treatment effect (the addition of oxaliplatin to the LV5FU2 regimen)
dAbsolute difference reflects a comparison of survival between the FOLFOX and LV5FU2 arms
eRelative difference reflects a ratio of the observed survival in the FOLFOX arm and the LV5FU2 arm [(X year OS rate in the FOLFOX group - X year OS rate in
the LV5FU2 group)/(X year OS rate in the LV5FU2 group) *100]