Table 2.
The adjusted hazard ratios of overall survival per 3-year period of diagnosis for HR + /HER2− ABC patients, corrected for patient- and tumour characteristics in three models using multivariable proportional hazard analysis.
| N (%) | All patients (N = 1950, 1469 events) |
N (%) | Patients with metachronous metastases (N = 1503, 1151 events) |
|||||
|---|---|---|---|---|---|---|---|---|
| Model 1 |
Model 2 |
Model 3 |
||||||
| Hazard ratio (95% CI) | p-value | Hazard ratio (95% CI) | p-value | Hazard ratio (95% CI) | p-value | |||
| Period of diagnosis | ||||||||
| 2008–2010 | 456 (23) | Ref | 362 (24) | Ref. | Ref. | |||
| 2011–2013 | 521 (27) | 0.88 (0.76–1.02) | 0.09 | 399 (27) | 0.88 (0.74–1.03) | 0.11 | 0.79 (0.67–0.94) | 0.007 |
| 2014–2016 | 480 (25) | 0.85 (0.73–0.99) | 0.03 | 366 (24) | 0.87 (0.74–1.03) | 0.12 | 0.71 (0.59–0.85) | <0.001 |
| 2017–2019 | 493 (25) | 0.76 (0.64–0.90) | 0.001 | 376 (25) | 0.75 (0.62–0.90) | 0.003 | 0.63 (0.51–0.77) | <0.001 |
| Age at diagnosis | ||||||||
| Per year | 1.02 (1.01–1.02) | <0.001 | 1.01 (1.01–1.02) | <0.001 | 1.02 (1.01–1.03) | <0.001 | ||
| Metastatic-free interval | ||||||||
| <3 months | 447 (23) | Ref. | ||||||
| 3–60 months | 510 (26) | 1.89 (1.62–2.20) | <0.001 | 510 (34) | Ref. | Ref. | ||
| 60–120 months | 443 (23) | 1.05 (0.89–1.23) | 0.58 | 443 (29) | 0.56 (0.48–0.65) | <0.001 | 0.55 (0.47–0.64) | <0.001 |
| >120 months | 550 (28) | 0.71 (0.60–0.83) | <0.001 | 550 (37) | 0.38 (0.33–0.44) | <0.001 | 0.43 (0.36–0.50) | <0.001 |
| Metastatic localization | ||||||||
| Bone-only | 639 (33) | Ref | 466 (31) | Ref. | Ref. | |||
| Soft tissue, without visceral or CNS | 230 (12) | 0.71 (0.55–0.90) | 0.005 | 169 (11) | 0.71 (0.54–0.94) | 0.02 | 0.70 (0.53–0.93) | 0.01 |
| Visceral, without CNS | 1014 (52) | 1.21 (1.00–1.47) | 0.05 | 811 (54) | 1.30 (1.05–1.61) | 0.02 | 1.29 (1.04–1.60) | 0.02 |
| CNS | 67 (3) | 1.88 (1.37–2.59) | <0.001 | 57 (4) | 1.77 (1.24–2.51) | 0.001 | 1.65 (1.16–2.35) | 0.005 |
| Number of metastatic sites | ||||||||
| Single | 907 (47) | Ref | 680 (45) | Ref. | Ref. | |||
| Multiple | 1043 (53) | 1.48 (1.25–1.77) | <0.001 | 823 (55) | 1.40 (1.15–1.70) | 0.001 | 1.43 (1.17–1.73) | <0.001 |
| (Neo-)Adjuvant chemotherapy | ||||||||
| No chemotherapy | – | – | 809 (54) | – | – | Ref. | ||
| AC or taxane | – | – | 276 (18) | – | – | 1.20 (0.98–1.46) | 0.08 | |
| AC and taxane | – | – | 334 (22) | – | – | 1.33 (1.08–1.62) | 0.007 | |
| Other chemotherapy | – | – | 84 (6) | – | – | 0.89 (0.65–1.22) | 0.48 | |
| (Neo-)Adjuvant ET | ||||||||
| No adjuvant ET | – | – | 468 (31) | – | – | Ref. | ||
| Tamoxifen or other | – | – | 397 (26) | – | – | 1.56 (1.30–1.88) | <0.001 | |
| AI with/without tamoxifen | – | – | 638 (42) | – | – | 1.88 (1.58–2.24) | <0.001 | |
ABC, advanced breast cancer; AC, anthracyclines and cyclophosphamide; AI, aromatase inhibitors; CNS, central nervous system; ET, endocrine therapy.
Model 1: Total study population; Model 2: patients with metachronous metastases without correcting for adjuvant therapies; Model 3: patients with metachronous metastases with correction for adjuvant therapies.