TABLE I.
Demographics and tumour characteristics of patients with breast cancer (BCa) based on site of initial metastasis and age
| Variable | Group A: Initial metastasis to a non-brain site | Group B: Initial metastasis to the brain | p Value | ||
|---|---|---|---|---|---|
|
| |||||
| <40 Years | ≥40 Years | <40 Years | ≥40 Years | ||
| Patients (n) | 10 | 63 | 7 | 41 | — |
|
| |||||
| Median age (years) | 36 | 55 | 35 | 56 | <40: 0.755 |
| ≥40: 0.389 | |||||
|
| |||||
| Sex [n (%)] | |||||
| Women | 9 (90) | 63 (100) | 7 (100) | 41 (100) | 0.011 |
| Men | 1 (10) | 0 (0) | 0 (0) | 0 (0) | |
|
| |||||
| Positive family history of BCa (first degree)[ n (%)] | |||||
| Unavailable | 3 (30) | 11 (17) | 1 (14) | 7 (17) | 0.248 |
| Yes | 1 (14) | 18 (35) | 0 (0) | 9 (26) | |
| No | 6 (86) | 34 (65) | 6 (100) | 25 (74) | |
|
| |||||
| BRCA1/2 status [n (%)] | |||||
| Unavailable | 6 (60) | 53 (84) | 5 (71) | 34 (83) | 0.442 |
| Yes | 1 (25) | 5 (50) | 1 (50) | 1 (14) | |
| No | 3 (75) | 5 (50) | 1 (50) | 6 (86) | |
|
| |||||
| Histology [n (%)] | |||||
| Ductal | 10 (100) | 56 (89) | 6 (86) | 30 (73) | 0.005 |
| Lobular | 0 (0) | 3 (5) | 0 (0) | 11 (27) | |
| Othera | 0 (0) | 4 (6) | 1 (14) | 0 (0) | |
|
| |||||
| BCa subtype [n (%)] | |||||
| HR-negative, HER2-negative | 1 (10) | 12 (19) | 2 (28,5) | 15 (36.5) | 0.644 |
| HR-negative, HER2-positive | 1 (10) | 4 (6) | 0 (0) | 3 (7) | |
| HR-positive, HER2-negative | 4 (40) | 30 (48) | 3 (43) | 15 (36.5) | |
| HR-positive, HER2-positive | 4 (40) | 17 (27) | 2 (28.5) | 8 (20) | |
a
Includes 1 malignant phyllodes tumour (≥40 years, initial metastasis at site other than brain), 2 ductal and lobular tumours (≥40 years, initial metastasis at site other than brain), 1 small-cell carcinoma (≥40 years, initial metastasis at site other than brain), 1 metaplastic carcinoma (<40 years, initial metastasis to brain).
HR = hormone receptor; HER2 = human epidermal growth factor receptor 2.