Table 2 Univariate cox proportional hazards model for overall survival
Variable | Category | Median OS (95% CI) | Hazard ratio (95% CI) | P value |
|---|---|---|---|---|
Year of diagnosis of brain metastasis | 2008–2014 | 14.3 (11.8–16.8) | 1 |  |
2015–2018 | 16.8 (13.4–20.2) | 0.74 (0.61–0.91) | 0.003 | |
Breast GPA score | 0.0–1.0 | 6.9 (5.3–8.5) | 1 | < 0.001 |
1.5–2.0 | 14.2 (11.2–17.2) | 0.49 (0.38–0.64) | < 0.001 | |
2.5–3.0 | 21.8 (17.7–25.9) | 0.30 (0.23–0.39) | < 0.001 | |
3.5–4.0 | 42.6 (20.1–65.1) | 0.14 (0.07–0.26) | < 0.001 | |
KPS at diagnosis of brain metastasis |  ≤ 60 | 6.9 (5.6–8.2) | 1 | < 0.001 |
70–80 | 16.7 (15.1–18.3) | 0.45 (0.35–0.57) | < 0.001 | |
90–10 | 39.3 (28.2–50.4) | 0.19 (0.12–0.30) | < 0.001 | |
Tumor subtype (primary breast cancer) | HR-/HER2- | 10.2 (7.8–12.6) | 1 | < 0.001 |
HR+/HER2- | 13.7 (9.8–17.6) | 0.81 (0.62–1.05) | 0.115 | |
HR−/HER2+ | 16.3 (13.4–19.2) | 0.65 (0.49–0.87) | 0.004 | |
HR + /HER2+ | 22.7(18.2–27.2) | 0.48 (0.36–0.65) | < 0.001 | |
Missing | 22.5 (0–50.1) | 0.52 (0.31–0.85) | 0.01 | |
Age at diagnosis of brain metastasis | ≥ 60 | 14.8 (9.7–19.9) | 1 |  |
< 60 | 15.9 (14.2–17.6) | 0.94 (0.75–1.19) | 0.628 | |
Number of brain metastasis | Multiple lesions | 13.1 (11.4–14.9) | 1 |  |
Single lesion | 19.2 (15.2–23.2) | 0.60 (0.48–0.75) | < 0.001 | |
Extracranial disease | Yes | 14.5 (12.6–16.4) | 1 |  |
No | 22.8 (19.4–26.2) | 0.58 (0.44–0.77) | < 0.001 | |
Interval between breast cancer to recurrence | ≤ 24 months | 14.9 (12.6–17.2) | 1 |  |
> 24 months | 16.6 (13.7–19.5) | 0.94 (0.77–1.15) | 0.54 | |
Interval between breast cancer to brain metastasis | ≤ 24 months | 14.8 (11.6–18.0) | 1 |  |
> 24 months | 16.3 (14.4–18.2) | 0.98 (0.79–1.21) | 0.816 | |
Number of involved organs | ≤ 3 | 20.0 (17.2–22.8) | 1 |  |
> 3 | 11.4 (9.5–13.3) | 1.61 (1.32–1.97) | < 0.001 | |
Number of metastatic lesions | > 5 | 12.2 (10.7–13.7) | 1 |  |
≤ 5 | 24.3 (20.9–27.7) | 0.46 (0.37–0.59) | < 0.001 | |
Asymptomatic brain metastasis | No | 14.2 (12.1–16.3) | 1 | 0.228 |
Yes | 18.4 (16.2–20.5) | 0.86 (0.38–0.63) | 0.141 | |
Missing | 13.8 (7.6–20.0) | 1.22 (0.51–3.00) | 0.655 | |
Salvage local therapies | No | 14.1 (12.1–16.1) | 1 |  |
Yes | 25.8 (22.3–29.3) | 0.51 (0.36–0.71) | < 0.001 | |
Chemotherapy | No | 5.3 (4.3–6.3) | 1 | < 0.001 |
Yes | 18.6 (16.8–20.4) | 0.35 (0.27–0.45) | < 0.001 | |
Missing | 10.6 (8.4–12.8) | 0.66 (0.44–0.98) | < 0.001 | |
Anti-HER2 therapy | HER2+ without anti-HER2 therapy | 10.2 (6.8–13.6) | 1 | < 0.001 |
HER2- without anti-HER2 therapy | 12.2 (10.0–14.4) | 1.01 (0.72–1.42) | 0.952 | |
Trastuzumab ± Pertuzumab | 18.4 (11.7–25.1) | 0.63 (0.40–0.98) | 0.039 | |
TKI(Pyritinib/Lapatinib) ± Trastuzumab | 21.8 (17.6–26.0) | 0.58 (0.39–0.86) | 0.006 | |
Other | 17.2 (11.4–23.0) | 0.91 (0.28–2.94) | 0.871 | |
Missing | 12.3 (N/A) | 0.99 (0.24–4.11) | 0.99 | |
Endocrine therapy | HR + with endocrine therapy | 25.0 (20.9–29.1) | 1 |  < 0.001 |
HR + without endocrine therapy | 12.4 (10.2–14.6) | 1.84 (1.38–2.47) | 0.001 | |
HR negative | 15.9 (13.4–18.4) | 1.70 (1.25–2.29) |  < 0.001 |