Table 5.
Multivariable COX-regression analyses of baseline clinical and histopathological characteristics on patient survivala.
| Variable | HR | 95% CI | p-value |
|---|---|---|---|
| Arm | |||
| CE-CT (Reference) | |||
| FDG-PET/CT | 0.44 | 0.29–0.68 | 0.001 |
| Primary breast cancer (clinical and surgical parameters) | |||
| Tumour size | 0.99 | 0.999–1.002 | 0.19 |
| Tumour histopathology (invasive ductal carcinoma as reference) | |||
| Invasive lobular carcinoma | 1.54 | 0.77–3.06 | 0.22 |
| Adenocarcinoma | 1.65 | 0.61–4.48 | 0.33 |
| Unknown | 1.004 | 0.36–2.78 | 0.99 |
| Oestrogen receptor status (positive as reference) | |||
| Negative | 1.58 | 0.72–3.50 | 0.26 |
| Unknown | 0.73 | 0.29–1.83 | 0.50 |
| HER2 receptor status (positive as reference) | |||
| Negative | 0.82 | 0.36–1.84 | 0.63 |
| Unknown | 1.40 | 0.55–3.52 | 0.48 |
| Tumour grade (grade 1 as reference) | |||
| Grade 2 | 0.88 | 0.51–1.51 | 0.65 |
| Grade 3 | 1.10 | 0.60–2.01 | 0.76 |
| Unknown | 0.72 | 0.36–1.45 | 0.36 |
| Lumpectomy / mastectomy | 1.30 | 0.57–3.00 | 0.53 |
| Lymph node involvement (no involvement as reference) | |||
| Single cell / micro-metastasis | 0.69 | 0.31–1.51 | 0.35 |
| Macro-metastasis | 1.09 | 0.71–1.69 | 0.68 |
| Unknown | 1.13 | 0.51–2.52 | 0.76 |
| Receiving adjuvant therapy | 1.26 | 0.70–2.26 | 0.44 |
| Receiving radiotherapy | 0.91 | 0.60–1.38 | 0.66 |
| Time until relapse (months) | 0.992 | 0.988–0.996 | <0.001 |
| Metastatic cancer (clinico-histopathological parameters) | |||
| Year of metastasis diagnosis | 1.15 | 1.06–1.26 | 0.001 |
| Age at metastasis (years) | 0.994 | 0.979–1.010 | 0.48 |
| Performance status ≥ 2 | 1.32 | 0.77–2.27 | 0.31 |
| Primary disseminated disease | 0.71 | 0.33–1.51 | 0.37 |
| Tumour histopathology (invasive ductal carcinoma as reference) | |||
| Invasive lobular carcinoma | 0.61 | 0.26–1.43 | 0.26 |
| Adenocarcinoma | 0.63 | 0.39–1.04 | 0.07 |
| Unknown | 0.51 | 0.29–0.90 | 0.02 |
| Oestrogen receptor status (positive as reference) | |||
| Negative | 3.02 | 1.38–6.62 | 0.006 |
| Unknown | 1.07 | 0.44–2.61 | 0.89 |
| HER2 receptor status (positive as reference) | |||
| Negative | 3.62 | 1.44–9.08 | 0.006 |
| Unknown | 8.21 | 2.99–22.60 | <0.001 |
| Referral oncologist (oncologist A as reference) | |||
| Oncologist B | 1.34 | 0.79–2.28 | 0.28 |
| Oncologist C | 0.65 | 0.36–1.18 | 0.15 |
| Oncologist D | 1.88 | 0.94–3.74 | 0.07 |
| Other oncologists | 0.91 | 0.54–1.53 | 0.71 |
| Tumour characteristics and region of metastasis at baseline scan | |||
| Oligometastases | 0.47 | 0.24–0.89 | 0.02 |
| Bone | 1.71 | 1.09–2.69 | 0.02 |
| Liver | 2.73 | 1.82–4.10 | <0.001 |
| Lung / Pleural | 0.97 | 0.66–1.41 | 0.86 |
| Regional / Distant lymph node | 0.97 | 0.65–1.42 | 0.86 |
HR hazard ratio, CI confidence interval, CE-CT contrast-enhanced computed tomography, FDG-PET/CT Fluorodeoxyglucose positron emission tomography with integrated computed tomography, HER2 human epidermal growth factor receptor-2.
aVariables considered in this model included baseline characteristics that are assumed to have potentially a prognostic value and in particular those which showed some imbalance between the groups.
Statistically significant p < 0.05 values are in bold.