Table II.
Univariate analyses of the influence of clinical factors on the PFS and OS of patients with BOM.
| PFS, % | OS, % | ||||||
|---|---|---|---|---|---|---|---|
| Characteristic | Number | 3 years | 5 years | P-value | 3 years | 5 years | P-value |
| Age at primary diagnosis, years | 0.246 | 0.244 | |||||
| <35 | 25 | 14.4 | 4.8 | 49.9 | 21.8 | ||
| 35-60 | 153 | 31.9 | 14.7 | 64.4 | 41.3 | ||
| ≥60 | 30 | 29.2 | 7.8 | 56.6 | 38.2 | ||
| Menopausal status at primary diagnosis | 0.879 | 0.740 | |||||
| Premenopause | 116 | 27.1 | 12.9 | 59.0 | 33.6 | ||
| Postmenopause | 92 | 32.6 | 11.0 | 65.2 | 46.2 | ||
| Lymph node status at primary diagnosis | 0.412 | 0.785 | |||||
| Negative | 61 | 31.7 | 16.4 | 69.2 | 41.4 | ||
| Positive | 147 | 29.2 | 11.3 | 59.1 | 37.7 | ||
| Tumor stage at primary diagnosis | 0.040 | 0.114 | |||||
| T1 | 53 | 43.7 | 20.7 | 67.4 | 50.3 | ||
| T2 | 103 | 20.6 | 13.2 | 59.6 | 37.0 | ||
| T3 | 34 | 28.4 | 11.8 | 61.3 | 29.6 | ||
| T4 | 18 | 39.9 | 0 | 62.2 | 23.3 | ||
| Clinical stage at primary diagnosis | 0.337 | 0.476 | |||||
| I | 24 | 39.4 | 24.6 | 72.2 | 49.4 | ||
| II | 75 | 23.7 | 17.9 | 66.5 | 37.7 | ||
| III | 61 | 28.3 | 7.7 | 51.5 | 34.1 | ||
| IV | 48 | 37.0 | 5.9 | 64.1 | 37.6 | ||
| Pathologic type at primary diagnosis | 0.118 | 0.149 | |||||
| Invasive ductal carcinoma | 170 | 27.7 | 12.3 | 59.2 | 37.3 | ||
| Others | 38 | 40.4 | 15.9 | 75.3 | 49.6 | ||
| HR status at primary diagnosis | <0.001 | <0.001 | |||||
| Negative | 39 | 9.6 | 4.8 | 30.5 | 13.1 | ||
| Positive | 169 | 34.7 | 14.9 | 69.3 | 45.3 | ||
| HER2 status at primary diagnosis | 0.032 | 0.168 | |||||
| Negative | 171 | 32.3 | 13.5 | 66.5 | 42.4 | ||
| Positive | 37 | 19.5 | 10.4 | 40.0 | 25.4 | ||
| Molecular subtype at primary diagnosis | 0.001 | <0.001 | |||||
| HR+/HER2− | 144 | 36.0 | 14.9 | 71.9 | 45.4 | ||
| HR/HER2+ | 40 | 20.4 | 12.8 | 42.8 | 26.4 | ||
| HR−/HER2− | 24 | 10.0 | 0 | 33.5 | 16.8 | ||
| Bone radiotherapy | 0.977 | 0.353 | |||||
| No | 131 | 29.3 | 12.4 | 59.2 | 36.3 | ||
| Yes | 77 | 30.4 | 13.6 | 66.7 | 42.3 | ||
| Bisphosphonate therapy | 0.967 | 0.386 | |||||
| No | 23 | 30.4 | 13.0 | 51.1 | 33.7 | ||
| Yes | 185 | 30.0 | 13.0 | 63.0 | 40.2 | ||
| Location of bone metastases at BOM diagnosis | 0.123 | 0.003 | |||||
| Axial | 164 | 28.1 | 11.8 | 63.4 | 40.1 | ||
| Appendicular | 7 | 71.4 | 53.6 | 85.7 | 71.4 | ||
| Axial and appendicular | 37 | 30.4 | 9.1 | 48.7 | 24.7 | ||
| Number of bone metastases at BOM diagnosis | 0.035 | 0.004 | |||||
| Single | 60 | 43.7 | 17.5 | 77.0 | 51.7 | ||
| Multiple | 148 | 24.4 | 11.2 | 56.1 | 33.3 | ||
HER2, human epidermal growth factor receptor 2; HR, hormone receptor; PFS, progression-free survival; OS, overall survival; BOM, bone-only metastasis.