Table 1. Selected baseline characteristics of EOC cases and matched controls at enrolment in the EPIC study.
| Cases (n=565)a | Controls (n=1097)a | P-valueb | |
|---|---|---|---|
| Age at blood donationc | 57.0 (33.6–80.7) | 56.9 (33.6–79.3) | |
| Age at diagnosis | 63.6 (37.4–86.5) | ||
| Lag time between blood donation and diagnosis | 6.7 (0–16) | ||
|
Menopausal status at blood donationb | |||
| Pre | 112 (20%) | 219 (20%) | |
| Post | 453 (80%) | 878 (80%) | |
| Age at menopaused | 50 (32–60) | 50 (30–59) | 0.03 |
| Ever full-term pregnancy | <0.01 | ||
| No | 95 (17%) | 124 (12%) | |
| Yes | 448 (83%) | 935 (88%) | |
| OC use | < 0.01 | ||
| Never | 349 (62%) | 594 (54%) | |
| Ever | 214 (38%) | 498 (46%) | |
| HRT useb | 0.57 | ||
| Never | 452 (87%) | 867 (86%) | |
| Ever | 69 (13%) | 145 (14%) | |
|
Histology | |||
| Serous | 302 (53%) | ||
| Mucinous | 41 (7%) | ||
| Endometrioid | 66 (12%) | ||
| Clear Cell | 28 (5%) | ||
| NOS | 99 (18%) | ||
| Other | 29 (5%) | ||
|
Gradee,f | |||
| Low grade | 35 (10%) | ||
| High grade | 308 (90%) | ||
|
Stagee,g | |||
| Low stage | 76 (15%) | ||
| High stage | 420 (85%) | ||
|
Type I/IIe | |||
| Type I | 67 (22%) | ||
| Type II | 242 (78%) | ||
| IGF-I (nmol l−1) h | 13.98 (13.39–14.6) | 14.06 (13.63–14.5) | 0.26 |
Abbreviations: EOC=epithelial ovarian cancer; EPIC=European Prospective Investigation into Cancer and Nutrition; HRT=hormone replacement therapy; IGF-I=insulin-like growth factor I.
Values are shown as median (range) or number (percentage).
Cases and controls in both study phases were matched on: study recruitment centre, age at blood donation (±6 months), time of the day of blood collection (±1 h), fasting status (<3 h, 3–6 h, >6 h) and menopausal status at blood collection (premenopausal, perimenopausal and postmenopausal), as well as menstrual cycle phase for premenopausal women (‘early follicular' (days 0–7 of the cycle), ‘late follicular' (days 8–11), ‘peri-ovulatory' (days 12–16), ‘mid-luteal' (days 20–24) and ‘other luteal' (days 17–19 or days 25–40 ). Cases missing data on the phase of menstrual cycle were matched to controls with missing information on menstrual cycle phase.
Among postmenopausal women only.
Matching factor.
Differences between cases and matched controls based on conditional logistic regression.
Percentages presented among women with data on tumour characteristics. Percentage of missing data: grade (39%), stage (12%) and type I/II status (45%).
Low-grade tumours: well differentiated tumours; high-grade tumours: moderately, poorly or undifferentiated tumours.
Low-stage tumours: localised tumours; high-grade tumours: regional metastatic or distant metastatic tumours.
Differences in IGF-I concentrations between cases and matched controls based on geometric mean (95% confidence interval); values from each study phase are standardised to a mean of 0 for analyses.