Table 2.
Univariate and multivariable analyses of overall survival in patients treated with IT therapy
| Categories | N | Univariate Cox model (N = 312) |
Multivariable Cox model (N = 312) |
||||
|---|---|---|---|---|---|---|---|
| Hazard ratio | 95% CI | P value | Hazard ratio | 95% CI | P value | ||
| IT therapy initiation period | |||||||
| 2008-2012 | 74 | 1 | 0.947 | ||||
| 2012-2018 | 238 | 0.99 | 0.74-1.32 | ||||
| Age at MBC, years | |||||||
| <55 | 175 | 1 | 0.618 | ||||
| ≥55 | 137 | 0.94 | 0.73-1.20 | ||||
| Time to MBC, months | |||||||
| <6 | 87 | 1 | 0.302 | ||||
| 6-24 | 52 | 1.03 | 0.71-1.50 | ||||
| 24-60 | 69 | 0.85 | 0.60-1.22 | ||||
| ≥60 | 102 | 0.77 | 0.56-1.07 | ||||
| ECOG performance status at initiation of IT therapy | |||||||
| PS 0-1 | 49 | 1 | 0.014 | 1 | 0.2 | ||
| PS 2 | 42 | 0.95 | 0.58-1.55 | 0.95 | 0.58-1.56 | ||
| PS 3-4 | 48 | 1.84 | 1.18-2.88 | 1.47 | 0.93-2.34 | ||
| PS NA | 173 | 1.39 | 0.97-1.98 | 1.3 | 0.9-1.88 | ||
| BC subtype | |||||||
| HR+/HER2− | 168 | 1 | <0.001 | 1 | <0.001 | ||
| HER2+ | 47 | 0.96 | 0.65-1.42 | 0.92 | 0.62-1.38 | ||
| TN | 77 | 1.87 | 1.39-2.51 | 1.81 | 1.32-2.47 | ||
| NA | 20 | 1.43 | 0.88-2.32 | 1.12 | 0.68-1.83 | ||
| Number of metastatic sites (excluding CNS) at initiation of IT therapy | |||||||
| <3 | 160 | 1 | 0.088 | 1 | <0.001 | ||
| ≥3 | 152 | 1.24 | 0.97-1.59 | 1.33 | 1.01-1.74 | ||
| Treatment line at initiation of IT therapy | |||||||
| Line 1 | 62 | 1 | 0.004 | 1 | <0.001 | ||
| Line 2 | 88 | 1.52 | 1.06-2.18 | 1.44 | 0.99-2.1 | ||
| Line ≥3 | 162 | 1.74 | 1.24-2.45 | 1.88 | 1.30-2.73 | ||
| Concomitant systemic therapy | |||||||
| No | 140 | 1 | <0.001 | 1 | <0.001 | ||
| Yes | 172 | 0.50 | 0.38-0.64 | 0.47 | 0.35-0.62 | ||
| Intrathecal agent | |||||||
| Methotrexate | 206 | 1 | 0.051 | 1 | <0.001 | ||
| Cytarabine/Thiotepa | 106 | 1.29 | 1-1.67 | 1.68 | 1.28-2.22 | ||
| Concomitant RT | |||||||
| No | 273 | 1 | 0.748 | ||||
| Yes | 39 | 0.94 | 0.66-1.35 | ||||
| Univariate Cox model for the scores evaluated | ||||
|---|---|---|---|---|
| N | Hazard ratio | 95% CI | P value | |
| Curie scorea | ||||
| 0 | 40 | 1 | <0.001 | |
| 1 | 123 | 1.31 | 0.87-1.98 | |
| 2-3 | 149 | 2.13 | 1.43-3.19 | |
| Breast-GPAa,b | ||||
| 0.0-1.0 | 74 | 1 | <0.001 | |
| 1.5-2.0 | 154 | 0.6 | 0.45-0.82 | |
| 2.5-4.0 | 63 | 0.46 | 0.31-0.68 | |
BC, breast cancer; CI, confidence interval; CNS, central nervous system; ECOG, Eastern Cooperative Oncology Group; GPA, graded prognostic assessment; HER2, human epidermal growth factor receptor 2; HR, hormone receptor; IT, intrathecal; MBC, metastatic breast cancer; NA, not available; PS, performance status; RT, radiotherapy; TN, triple negative.
a
Because only eight patients had a Curie score of 3 and only four patients had a Breast-GPA score of 3.5-4.0, these patients were grouped with patients with a Curie score of 2 and a Breast-GPA score of 2.5-3.0, respectively.
b
Twenty-one patients had Breast-GPA NA due to missing data for BC subtype.