Table 1. Multivariate analysis of disease-free survival at 2.75 years (N=3779; 360 DFS events).
| Variable | Hazard ratio (95% CI) | Wald χ2 | P-value |
|---|---|---|---|
| Age (per 10 years) |
1.35 (1.20–1.52) |
26.0 |
<0.001 |
| ER (per 50 histoscore units) |
0.88 (0.81–0.96) |
9.2 |
0.002 |
| PgR (per 50 histoscore units) |
0.87 (0.81–0.92) |
18.7 |
<0.001 |
| Ki67 (per 10%) |
1.07 (1.01–1.13) |
4.6 |
0.03 |
| Tumour sizea |
NA |
6.2 |
0.01 |
| Number of positive nodesa |
NA |
50.6 |
<0.001 |
| Second degree transformation (^2) |
NA |
18.4 |
<0.001 |
|
Tumour grade | |||
| 1 | 1.00 | 6.7 | 0.04 |
| 2 | 1.0 (0.68–1.47) | ||
| 3 |
1.33 (0.90–1.99) |
|
|
| HER1–3 |
0.94 (0.70–1.27) |
0.1 |
0.7 |
| Treatment |
1.24 (0.90–1.71) |
1.7 |
0.2 |
| HER1–3 treatment interaction | 0.55 (0.36–0.83) | 7.8 | 0.005 |
Abbreviations: CI = confidence interval; ER=oestrogen receptor; HER=human epidermal growth factor receptor; PgR=progesterone receptor; NA=not available.
a
Nonlinear transformations for number of positive nodes (^2), tumour size (^–0.5).
Prior chemotherapy (Y/N) was a nonsignificant variable excluded from the model. Units (see text) Age=years, ER/PgR=histoscore (0–300), and Ki67=per cent positive cells.
Hazard ratios for continuous variables (Age, ER/PgR, and Ki67) are expressed for an interval of 10 years (Age), 50 histoscore units (ER/PgR) or 10% change in positivity (Ki67).