Table 1.
Baseline characteristics of the study population
| Characteristic | Breast cancer survivors (n = 173) |
Cancer-free reference women (n = 346) |
P |
|---|---|---|---|
| Age, years, mean (SD) | 63.8 (6.5) | 61.7 (6.2) | < .001 |
| Body mass index, kg/m2, mean (SD) | 26.7 (4.6) | 27.4 (4.6) | .11 |
| Systolic blood pressure, mmHga, mean (SD) | 139 (19) | 131 (19) | < .001 |
| Diastolic blood pressure, mmHga, mean (SD) | 84 (10) | 81 (11) | .03 |
| Age at menopause, years, mean (SD) | 44.1 (5.1) | 49.3 (5.8) | < .001 |
| Diabetes, No (%) | 13 (7.5) | 12 (3.5) | .07 |
| Smoker status, No (%) | |||
| Never | 60 (34.7) | 132 (38.2) | .003 |
| Former | 95 (54.9) | 95 (41.4) | |
| Current | 18 (10.4) | 70 (20.3) | |
| Antihypertensive medication, No (%) | 60 (34.7) | 1 (0.3) | < .001 |
| Anticoagulant medication, No (%) | 16 (9.2) | 39 (11.4) | .54 |
| Lipid-lowering medication, No (%) | 31 (17.9) | 85 (24.9) | .09 |
| Education level, No (%) | .002 | ||
| Primary | 15 (8.7) | 45 (13.0) | |
| Lower | 67 (38.7) | 172 (49.9) | |
| Intermediate | 36 (20.8) | 67 (19.4) | |
| Higher | 15 (31.8) | 61 (17.7) | |
| Total brain volume, mL, mean (SD) | 902 (76) | 900 (80) | .72 |
| Age at cancer diagnosis, years, mean (SD) | 42.6 (5.4) | ||
| Time since diagnosis in years, mean (SD) | 21.1 (4.4) | ||
| Side of tumor, right side, No (%) | 89 (51.4) | ||
| Radiation field, No (%) | |||
| Carotid artery not in radiation fieldb | 17 (9.9) | ||
| Carotid artery partly in radiation fieldc | 102 (59.6) | ||
| Carotid artery in radiation fieldd | 52 (30.4) |
Side of tumor and radiation field were missing for one breast cancer survivor. SD = standard deviation
aIn sitting position
bAxillary, breast, or chest wall radiation
cInternal mammary chain radiation
dMcWhirter (supraclavicular and axillary) or supraclavicular radiation