Table 2.
Cox regression uni- and multivariable models for BCFi and OS by PAM50 subtypes and St. Gallen 2013 surrogate subtypes for different time intervals in patients with ER-positive/HER2-negative tumours.
| Univariable | Multivariablea | |||
|---|---|---|---|---|
| BCFi | OS | BCFi | OS | |
| HR (95% CI); P-value | ||||
|
PAM50 subtype (ER+/HER2− cohort) |
0–10 years | |||
| (n = 236, n = 102 events) overall P-value = 0.01d | (n = 236, n = 74 events) overall P-value < 0.001d | (n = 233, n = 102 events) overall P-value = 0.04d | (n = 233, n = 74 events) overall P-value = 0.01d | |
| LumA (Ref.) | 1.00 | 1.00 | 1.00 | 1.00 |
| LumB | 1.93 (1.27–2.93); 0.002 | 2.55 (1.56–4.17); <0.001 | 2.02 (1.26–3.26); 0.004 | 2.42 (1.37–4.28); 0.002 |
| HER2-E | 2.22 (1.01–4.91); 0.05 | 4.34 (1.92–9.85); <0.001 | 1.74 (0.69–4.40); 0.24 | 3.35 (1.25–8.98); 0.02 |
| Basal-like | 1.25 (0.39–4.04); 0.70 | 2.38 (0.72–7.85); 0.16 | 1.17 (0.34–4.03); 0.80 | 1.67 (0.46–6.00); 0.43 |
| >10 yearsb | ||||
| (n = 130, n = 43 events) | (n = 162, n = 77 events) overall P-value = 0.74d | (n = 127, n = 42 events) | (n = 159, n = 77 events) overall P-value = 0.31d | |
| LumA (Ref.) | 1.00 | 1.00 | 1.00 | 1.00 |
| LumB | 0.92 (0.45–1.87); 0.81 | 0.86 (0.50–1.48); 0.58 | 1.91 (0.79–4.59); 0.15 | 1.66 (0.87–3.16); 0.12 |
| HER2-E | – | 0.76 (0.18–3.12); 0.70 | – | 3.50 (0.63–19.45); 0.15 |
| Basal-like | – | 0.38 (0.05–2.76); 0.34 | – | 2.36 (0.25–22.11); 0.45 |
| Maximum follow-up timec | ||||
| (n = 236, n = 145 events) overall P-value = 0.08d | (n = 236, n = 151 events) overall P-value = 0.05d | (n = 233, n = 144 events) overall P-value = 0.02d | (n = 233, n = 151 events) overall P-value = 0.006d | |
| LumA (Ref.) | 1.00 | 1.00 | 1.00 | 1.00 |
| LumB | 1.56 (1.09–2.22); 0.01 | 1.49 (1.05–2.12); 0.03 | 1.89 (1.25–2.86); 0.003 | 1.93 (1.28–2.92); 0.002 |
| HER2-E | 1.35 (0.62–2.93); 0.45 | 2.11 (1.06–4.20); 0.04 | 1.50 (0.62–3.67); 0.37 | 3.04 (1.33–6.95); 0.008 |
| Basal-like | 0.73 (0.23–2.30); 0.59 | 1.05 (0.38–2.87); 0.93 | 0.82 (0.24–2.74); 0.75 | 1.45 (0.49–4.28); 0.50 |
| St. Gallen 2013/PAM50 subtype | 0–10 years | |||
| (n = 207, n = 87 events) overall P-value = 0.007d | (n = 207, n = 60 events) overall P-value = 0.001d | (n = 205, n = 87 events) overall P-value = 0.04d | (n = 205, n = 60 events) overall P-value = 0.03d | |
| LumBSC/LumBPAM50 (Ref.) | 1.00 | 1.00 | 1.00 | 1.00 |
| LumBSC/LumAPAM50 | 0.52 (0.33–0.83); 0.006 | 0.37 (0.21–0.66); 0.001 | 0.50 (0.29–0.84); 0.009 | 0.38 (0.20–0.74); 0.004 |
| LumASC/LumBPAM50 | 0.49 (0.12–2.05); 0.33 | 0.76 (0.18–3.20); 0.71 | 0.77 (0.18–3.32); 0.72 | 1.12 (0.25–5.07); 0.88 |
| LumASC/LumAPAM50 | 0.39 (0.21–0.73); 0.003 | 0.32 (0.15–0.68); 0.003 | 0.45 (0.23–0.91); 0.03 | 0.44 (0.19–1.01); 0.05 |
| >10 yearsb | ||||
| (n = 117, n = 42 events) overall P-value = 0.06e | (n = 147, n = 70 events) overall P-value = 0.56e | (n = 115, n = 41 events) overall P-value = 0.06e | (n = 145, n = 70 events) overall P-value = 0.56e | |
| LumBSC/LumBPAM50 (Ref.) | 1.00 | 1.00 | 1.00 | 1.00 |
| LumBSC/LumAPAM50 | 1.30 (0.62–2.69); 0.49 | 1.11 (0.62–1.98); 0.72 | 0.64 (0.26–1.60); 0.34 | 0.59 (0.30–1.15); 0.12 |
| LumASC/LumBPAM50 | – | – | – | – |
| LumASC/LumAPAM50 | 0.45 (0.16–1.23); 0.12 | 0.81 (0.41–1.59); 0.54 | 0.26 (0.08–0.80); 0.02 | 0.38 (0.18–0.84);0.02 |
| Maximum follow-up timec | ||||
| (n = 207, n = 129 events) overall P-value = 0.004d | (n = 207, n = 130 events) overall P-value = 0.02d | (n = 205, n = 128 events) overall P-value = 0.01d | (n = 205, n = 130 events) overall P-value = 0.008d | |
| LumBSC/LumBPAM50 (Ref.) | 1.00 | 1.00 | 1.00 | 1.00 |
| LumBSC/LumAPAM50 | 0.70 (0.47–1.02); 0.06 | 0.65 (0.44–0.96); 0.03 | 0.58 (0.37–0.90); 0.02 | 0.50 (0.32–0.79); 0.003 |
| LumASC/LumBPAM50 | 0.34 (0.08–1.41); 0.14 | 0.37 (0.09–1.52); 0.17 | 0.52 (0.12–2.24); 0.38 | 0.48 (0.11–2.05): 0.32 |
| LumASC/LumAPAM50 | 0.39 (0.23–0.67); 0.001 | 0.51 (0.32–0.83); 0.007 | 0.39 (0.21–0.70); 0.002 | 0.43 (0.25–0.74); 0.003 |
BCFi breast cancer-free interval, CI confidence interval, ER oestrogen receptor, HER2-E human epidermal growth factor receptor 2-enriched, HR hazard ratio, Lum Luminal, NHG Nottingham histological grade, OS overall survival, SC surrogate classification.
aAll analyses are stratified by study region and adjusted for age (continuous), tumour size (>20 vs ≤20 mm), NHG (1 vs 2 vs 3), nodal status (N0 vs N1 vs N2) and treatment arm.
bFrom year 10 to maximum follow-up time.
c32 and 36 years regarding BCFi and OS, respectively.
dOverall P-value, three degree of freedom Wald test.
eOverall P-value, two degree of freedom Wald test.