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.