Table 2.
The population attributable risks and estimated number of new cancer cases in Korean women caused by modifiable reproductive factors in the year 2010
| Cancer site | Risk factors | Population attributable risks % (95 % 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) |
aPAFs were considered only for parous females (97 % of total females)
bPAFs were considered only for post-menopausal females (32 % for total females)
cAttributable number of cases = population attributable risk X numbers of breast or ovarian cancer incidence in the year 2010 from National Cancer Registry
dThe population attributable risk exceed 100 (102.1) and truncated to 100