Table 1.
Comparison of ovarian cancer cases and matched controls
| Characteristic | Cases (n = 83) n (%) | Controls (n = 83) n (%) |
| Year of birth (median) | 1953 (range 1928–1971) | 1953 (range 1929–1971) |
| Age of 1st live birth (median) | 22 (range 16–38) | 23 (range 17–35) |
| Age at menarche (median) | 14 (range 10–17) | 14 (range 9–18) |
| BMI (median) | 25 (range 19–38) | 25 (range 17–44) |
| Age (median) | 45a (range 25–71) | 49b (range 31–73) |
| Parity | ||
| 0 | 7 (8) | 7 (8) |
| 1 | 11 (13) | 12 (14) |
| 2 | 43 (52) | 41 (50) |
| 3 | 13 (16) | 17 (20) |
| 4 | 7 (8) | 4 (5) |
| >4 | 2 (3) | 2 (3) |
| Breastfeedingc | ||
| ≤ 12 months | 20 (26) | 23 (30) |
| >12 months | 56 (74) | 53 (70) |
| OC use | ||
| <5 years | 83 (100) | 75 (90) |
| ≥ 5 years | 0 (0) | 8 (10) |
| HRT | ||
| Never | 81 (97) | 72 (87) |
| Ever | 2 (3) | 11 (13) |
| Smokingd | ||
| <4 pack-years | 56 (67) | 52 (63) |
| ≥ 4 pack-years | 24 (29) | 31 (37) |
| BRCA1 mutation | ||
| 5382insC | 61 (74) | 61 (74) |
| 300T>G | 16 (19) | 16 (19) |
| 4154delA | 6 (7) | 6 (7) |
BMI: body mass index; OC: oral contraceptive; HRT: hormone replacement therapy.
a Age at diagnosis of ovarian cancer.
b Age at the time of matching.
c Nulliparous women were excluded.
d Missing information on smoking status from three cases.