Cancer site | Risk factors | Population attributable risks % (95Â % CI) | Attributed N of casesc |
---|---|---|---|
Breast | Pregnancy/age at first birth | 8.0 (7.4-8.6) | 1152 (1066–1246) |
 | (Nullipara or age at first birth ≥ 24 years) | ||
 | Total period of breast feedinga | 3.1 (3.1-3.2) | 453 (441–464) |
(Duration of breast feeding ≤ 6 months) | |||
 | Oral contraceptive use (Ever) | 5.3 (5.1-5.5) | 763 (732–795) |
 | Hormone replacement therapy use (Ever)b | 0.3 (0.2-0.3) | 37 (29–44) |
 | Total | 16.7 (15.8-17.6) | 2404 (2283–2535) |
Ovary | Pregnancy (Nulliparous) | 1.2 (1.2-1.2) | 24 (24–24) |
 | Breast feeding experience (Never)a | 2.9 (2.8-2.9) | 55 (55–56) |
 | Tubal ligation (No)a | 24.5 (23.0-26.2) | 473 (444–504) |
 | Oral contraceptive use (Never) | 53.3 (27.9-100.0d) | 1027 (537–1927) |
 | Total | 81.9 (55.0-100.0 d) | 1579 (1059–1927) |
 |  |  | Attributed % of cases |
 | % of breast cancer in women |  | 16.7 (15.8-17.6) |
 | % of ovary cancer in women |  | 81.9 (55.0-100.0d) |