Table 1.
Demographic and clinical variables of participants
| Variable | BCC + (n = 34) | BCC − (n = 32) | NC (n = 35) | p |
|---|---|---|---|---|
| Age at T1 in years (M ± SD) | 49.7 ± 9.8 | 50.8 ± 7.1 | 49.6 ± 10.3 | 0.836 |
| Age at T2 in years (M ± SD) | 50.6 ± 9.8 | 52.0 ± 7.4 | 50.6 ± 10.2 | 0.777 |
| Estimated IQ | 101.3 ± 13.7 | 104.6 ± 12.8 | 107.4 ± 12.8 | 0.160 |
| Educational level [n (%)] | ||||
| Low | 3 (8.8) | 5 (15.6) | 0 (0) | 0.198 |
| Middle | 8 (23.5) | 8 (25) | 8 (22.8) | |
| High | 23 (67.6) | 19 (59.4) | 27 (77.1) | |
| Premenopausal [n (%)] | ||||
| T1 | 19 (55.9) | 16 (50) | 17 (48.6) | 0.835 |
| T2 | 1 (2.9) | 13 (40.6) | 17 (48.6) | < 0.001a, b |
| Time between T1 and T2 (days) | 332.9 ± 61.5 | 340.9 ± 43.4 | 365.3 ± 62.8 | 0.053 |
| Breast cancer gradingc [n (%)] | ||||
| 1 | 2 (5.9) | 11 (34.4) | 0.020b | |
| 2 | 17 (50) | 11 (34.4) | ||
| 3 | 11 (32.4) | 5 (15.6) | ||
| Side of breast affected [n (%)] | ||||
| Right | 12 (40) | 15 (46.9) | 0.300 | |
| Left | 18 (60) | 13 (40.6) | ||
| Histology [n (%)] | ||||
| In-situ carcinoma | 0 | 16 (57.1) | < 0.001b | |
| Invasive carcinoma | 30 (100) | 10 (35.7) | ||
| Isolated tumor cells | 0 | 2 (7.1) | ||
| Origin [n (%)] | ||||
| Ductal | 28(93.3) | 25(89.3) | 0.078 | |
| Lobular | 2(0.07) | 0 | ||
| Isolated tumor cells | 0 | 3(0.11) | ||
| Treatment [n (%)] | ||||
| Radiotherapy | 25 (73.5) | 19 (59.4) | 0.223 | |
| Tamoxifen | 22 (64.7) | NA | ||
| Type of surgery | ||||
| Wide local excision | 19 (55.9) | 20 (62.5) | 0.512 | |
| Mastectomy | 11 (32.2) | 8 (25) | ||
| Chemotherapy complications [n (%)] | ||||
| No | 20 (58.8) | NA | ||
| Yes | 11 (32.4) | NA | ||
| Time since chemotherapy(days) | 208.5 ± 72.0 | NA | ||
BCC + breast cancer patients receiving chemotherapy, BCC − breast cancer patients with no chemotherapy, NC non-cancer controls, IQ intelligence quotient, NART dutch version of the national adult reading test, NA not applicable
Values indicate mean ± SD unless indicated otherwise
Significance was declared by p < 0.05 and significant differences are highlighted in bold
aIndicates a significant difference between BCC + and NC
bIndicates a significant difference between BCC + and BCC −
cGrade 1 refers to well differentiated, 2 moderately differentiated and 3 poorly differentiated