Table 2.

Univariate and multivariate analysis for PFS and OS in patients with metastatic breast cancer

PFSOS
Cox regression analysisUnivariateMultivariateUnivariateMultivariate
CovariatesHR (95% CI)PHR (95% CI)PHR (95% CI)PHR (95% CI)P
Age (≤59)1.089 (0.759–1.562)0.6431.021 (0.697–1.496)0.915
Performance status (2–3)1.451 (0.860–2.447)0.1631.425 (0.833–2.439)0.196
Menopausal status (pre)1.201 (0.535–2.696)0.6581.085 (0.481–2.450)0.844
Grade (III vs. I/II)1.128 (0.766–1.662)0.5421.072 (0.712–1.613)0.739
Adjuvant chemotherapy (yes)1.206 (0.839–1.733)0.3121.151 (0.785–1.687)0.471
Molecular subtype of tumor
 ER-positive0.737 (0.491–1.106)0.1410.491 (0.321–0.753)0.001*0.709 (0.400–1.256)0.239
 PgR-positive0.865 (0.587–1.274)0.1620.743 (0.494–1.116)0.152
 HER2-positive0.972 (0.630–1.502)0.8991.055 (0.665–1.675)0.819
 Triple-negative1.649 (0.982–2.770)0.0591.826 (1.055–3.161)0.031*2.738 (1.612–4.650)0.000 *2.591 (1.500–4.477)0.001 *
 No of organs affected (≥3)1.196 (0.812–1.762)0.3661.256 (0.838–1.882)0.269
Metastatic sites
 Liver1.709 (1.161–2.516)0.007*1.945 (1.276–2.963)0.002*1.746 (1.157–2.635)0.008*1.639 (1.082–2.482)0.020 *
 Lung1.014 (0.692–1.486)0.9411.024 (0.681–1.539)0.910
 Bones1.308 (0.905–1.890)0.1531.222 (0.827–1.805)0.314
 Lymph nodes1.088 (0.737–1.606)0.6721.036 (0.686–1.566)0.866
 CNS0.958 (0.419–2.186)0.9180.771 (0.337–1.763)0.538
 Skin0.869 (0.440–1.717)0.6860.959 (0.484–1.903)0.906
Type of first-line chemotherapy
 Taxane- or anthracyclin- single agents (reference)
 Taxane-based1.317 (0.782–2.219)0.3010.993 (0.585–1.687)0.981
 Combination without taxanes or anthracyclines1.791 (1.002–3.201)0.049*2.086 (1.154–3.774)0.015*1.004 (0.553–1.823)0.989
 CSC+/partial-EMT+ CTCs1.586 (1.060–2.374)0.025*1.785 (1.171–2.720)0.007*1.322 (0.856–2.042)0.207
  • NOTE: Univariate and multivariate Cox regression analysis was performed to estimate the risk for relapse and death of patients with metastatic breast cancer. Parameters showing statistical significance (*) or a trend for significance (Italics) in the univariate Cox regression analysis were subsequently included in a multivariate Cox proportional hazards regression model to evaluate whether they were independently associated with the risk for progression and death. The detection of CSC+/partial-EMT+ CTCs at baseline was an independent factor predicting for increased risk of relapse. Similarly, combination therapy not including taxanes or anthracyclines was associated with increased risk of relapse. Triple-negative status of the primary tumor and liver metastases independently predicted for increased risk of relapse and death.

  • Abbreviation: HR; hazard ratio (Bold).