Table 1

Incident breast cancer cases among postmenopausal women

WAANHJAL-USL-NUSTotal
All postmenopausal women
 No. of women20,79418,5275,91823,6389,8749,96188,712
 No. of breast cancer cases4623481575141681081,757
 RRs1.00.801.310.950.740.51
 Incidence ratesa339.5269.9444.8321.6250.2172.8
All women with natural menopause or bilateral oophorectomy
 No. of women14,0799,5273,63616,5765,9305,61655,364
 No. of breast cancer cases30617595366103711,116
 RRs1.00.781.330.990.770.60
 Incidence ratesa319.1250.2424.4314.3245.4192.7
  • a Adjusted to 1970 US Standard Population ages 45–79 years. This is calculated for Ws, and the incidence rates for other groups are computed by multiplying this figure by the RRs.