Table 1.
Mean values and distribution of study participants according to the main characteristics for 87 case–case sets (EPIC Florence, low- vs high-MBD BC case–case study).
| Variables | Low MBD cases N = 87 |
High MBD cases N = 87 |
p value |
|---|---|---|---|
| Mean (SD) or N (%) | Mean (SD) or N (%) | ||
| Age at blood collection (years) | 54.3 (6.7) | 51.6 (6.9) | 0.01j |
| Age at diagnosis (years) | 62.9 (6.4) | 59.8 (6,8) | 0.002j |
| Length of follow-up from blood collection (years) | 8.6 (4.6) | 8.2 (4.5) | 0.65k |
| Mean time between blood collection and mammographic examinations (years) | 6.1 (5.0) | 6.4 (4.9) | 0.78j |
| Mean time between mammographic examinations and breast cancer (years) | 2.5 (2.8) | 1.8 (2.6) | 0.12j |
| Diabetesa | |||
| No | 84 (98.8) | 85 (97.7) | |
| Yes | 1 (1.2) | 2 (2.3) | 0.57l |
| Hyperlipidaemiab | |||
| No | 59 (70.2) | 67 (77.0) | |
| Yes | 25 (28.8) | 20 (23.0) | 0.32l |
| Hypertensiona | |||
| No | 69 (81.2) | 71 (81.6) | |
| Yes | 16 (18.8) | 16 (18.4) | 0.94l |
| Tumor characteristics | |||
| Cancer sizec | |||
| T1 (< 2 cm) | 55 (71.4) | 53 (71.6) | |
| T2 (2–5 cm) | 9 (11.7) | 10 (13.5) | |
| T3 (> 5 cm) | 1 (1.3) | 0 (0.0) | |
| T4 (any size, growing into the chest wall or skin) | 1 (1.3) | 0 (0.0) | |
| Tis (in situ) | 11 (14.3) | 11 (14.9) | 0.73 l |
| Lymph node statusd | |||
| Negative | 47 (77.0) | 41 (66.1) | |
| Positive | 14 (23.0) | 21 (38.9) | 0.60 l |
| ER statuse | |||
| Negative | 6 (7.9) | 13 (18,8) | |
| Positive | 70 (92.1) | 56 (81.2) | 0.05l |
| PR statuse | |||
| Negative | 35 (46.1) | 27 (39.1) | |
| Positive | 41 (53.9) | 42 (60.9) | 0.40l |
| Reproductive history | |||
| Age at first menstrual period (years) | 12.2 (1.6) | 12.4 (1.4) | 0.30k |
| Contraceptive pilla | |||
| No | 48 (56.5) | 53 (60.9) | |
| Yes | 37 (43.5) | 34 (39.1) | 0.55l |
| Number of full-term pregnancies | |||
| 0 | 8 (9.2) | 20 (23.0) | |
| 1 | 30 (34.5) | 32 (36.8) | |
| 2 | 33 (37.9) | 33 (37.9) | |
| ≥ 3 | 16 (18.4) | 2 (2.3) | 0.006l |
| Age at first full-term pregnancy (years) | 26.0 (4.6) | 26.9 (3.9) | 0.24j |
| Breastfeeding | |||
| Nog | 18 (20.7) | 30 (34.5) | |
| Yes | 69 (79.3) | 57 (65.5) | 0.04l |
| Breastfeeding months (126 breastfeeding women) | 9.5 (6.6) | 5.7 (3.3) | 0.0001j |
| Menopausal status at blood collectiona | |||
| Premenopausal | 21 (24.7) | 34 (39.1) | |
| Postmenopausal | 64 (75.3) | 53 (60.9) | 0.043l |
| Menopausal status at mammographic examinationf | |||
| Premenopausal | 3 (3.6) | 13 (15.5) | |
| Postmenopausal | 81 (96.4) | 71 (84.5) | 0.009l |
| Menopausal hormones use at blood collectionh | |||
| No | 42 (71.2) | 34 (81.0) | |
| Yes | 17 (28.8) | 8 (19.0) | 0.26l |
| Menopausal hormones use at mammographic examinationi | |||
| No | 46 (93.9) | 37 (90.2) | |
| Yes | 3 (6.1) | 4 (9.8) | 0.52l |
| Anthropometric measures | |||
| Height (cm) | 160.5 (5.9) | 161.0 (5.7) | 0.56j |
| Weight (kg) | 71.9 (11.4) | 60.7 (8.4) | < 0.0001j |
| Body Mass Index (kg/m2) | 27.9 (4.5) | 23 (3.3) | < 0.0001j |
| Waist/hip ratio | 0.80 (0.07) | 0.76 (0.06) | < 0.0001k |
aMissing = 2; bmissing = 3; cmissing = 23; dmissing = 51; emissing = 29; fmissing = 6.
gNo breastfeeding women or women with no full-term pregnancies.
hPostmenopausal women at blood collection = 117 (missing = 16).
iPostmenopausal women at mammographic examination = 152 (missing = 62).
jp value from t test.
kp value from Wilcoxon rank-sum test.
lp value from Pearson's chi-squared.