Table 6: Univariate analysis of factors predicting time to progression during T-DM1 treatment.
| HR | 95%CI | p-value | |
| Age | 1.02 | 0.98-1.04 | 0.35 |
| ER/PgR status | 1.09 | 0.59-2.01 | 0.77 |
| HER2 status | 0.85 | 0.36-2.03 | 0.71 |
| Stage IV/Recurrence | 0.99 | 0.84-1.18 | 0.96 |
| Disease-free interval | 1.01 | 0.99-1.02 | 0.24 |
| Metastatic sites | |||
| Number of metastatic organs (single/multiple) | 1.27 | 0.60-2.68 | 0.54 |
| Visceral involvement | 1.12 | 0.53-2.36 | 0.77 |
| Presence of liver metastases | 0.73 | 0.37-1.42 | 0.36 |
| Presence of brain metastases | 1.82 | 0.37-1.68 | 0.58 |
| Number of previous regimens for metastatic breast cancer | 1.03 | 0.91-1.17 | 0.6 |
| Previous anti-HER2 therapies for metastatic breast cancer | |||
| Pertuzumab | 1.23 | 0.65-2.34 | 0.53 |
| Lapatinib | 1.13 | 0.58-2.15 | 0.72 |
| Time since diagnosis of metastatic breast cancer | 1 | 0.99-1.01 | 0.66 |
HR: hazard ratio; CI: confidence interval.