Factors Associated with OS
| Total no. of… | Median survival (mos) | Univariate analysis | Multivariate analysis | ||||||
| Variable | Patients | Patient deaths | P | Hazard ratio | 95% confidence interval for hazard ratio | P | Hazard ratio | 95% confidence interval for hazard ratio | |
| ER* | |||||||||
| Negative | 12 | 7 | 13.08 | — | 1.00 | — | — | 1.00 | — |
| Positive | 43 | 11 | — | 0.01 | 0.30 | 0.12–0.79 | 0.01 | 0.30 | 0.12–0.79 |
| HER2 | |||||||||
| Nonamplified | 46 | 18 | 24.54 | — | 1.00 | — | |||
| Amplified | 9 | 0 | — | 0.99 | — | — | |||
| Line of therapy | |||||||||
| First line | 19 | 6 | — | — | 1.00 | — | |||
| Later | 36 | 12 | — | 0.93 | 1.11 | 0.42–2.97 | |||
| Metastatic site | |||||||||
| Bone only | 26 | 7 | 24.74 | — | 1.00 | — | |||
| Bone plus soft tissue | 29 | 11 | — | 0.49 | 1.40 | 0.54–3.63 | |||
| Baseline CTC count | |||||||||
| <5 | 19 | 5 | — | — | 1.00 | — | |||
| ≥5 | 36 | 13 | 24.74 | 0.74 | 1.19 | 0.42–3.35 | |||
| Follow-up CTC count* | |||||||||
| <5 | 33 | 7 | — | — | 1.00 | — | |||
| ≥5 | 22 | 11 | 23.49 | 0.02 | 2.99 | 1.16–7.75 | |||
| PET/CT follow-up assessment | |||||||||
| Nonprogression | 38 | 9 | — | — | 1.00 | — | |||
| Progression | 17 | 9 | 18.96 | 0.01 | 3.29 | 1.28–8.48 | |||
↵* Factors with P value < 0.10 from univariate analysis are included in multivariate analysis.