Table 5.

Risk of premenopausal breast cancer according to modifications in body size and shape in different periods of life

CharacteristicsNo. of Cases/Non-casesAge-Adjusted RR95% CIMultivariate RR*95% CIMultivariate RR95% CI
Difference in body size and shape between age 7 and adulthood (age 18 and age at cohort enrolment)
    Remained thin54/6,2061.090.81-1.471.070.79-1.440.960.70-1.32
    Decreased weight156/19,7830.950.79-1.140.930.77-1.130.940.77-1.13
    Remained at an average weight178/22,2861.0 (reference)1.0 (reference)1.0 (reference)
    Increased weight294/42,8590.870.73-1.030.870.73-1.030.970.80-1.17
    Remained fat7/1,7090.610.29-1.280.600.29-1.280.780.36-1.68
P for linear trend0.030.060.94
Adult BMI change (difference between age 18 and at recruitment)
    Decreased in BMI140/17,4830.910.71-1.160.900.70-1.150.890.69-1.14
    Increased 0-1.4131/16,0861.0 (reference)1.0 (reference)1.0 (reference)
    Increased 1.5-4.0259/33,8990.900.74-1.100.910.75-1.110.980.80-1.20
    Increased >4.0150/23,8970.740.59-0.920.760.60-0.950.950.72-1.25
P for linear trend0.040.070.37
  • * Multivariate adjustment for age at enrolment, parity, age at first birth, oral contraceptive use, age at menarche, family history of breast cancer, total duration of breast-feeding, and country of residence.

  • Same model as above, adding BMI at enrolment as an additional covariate.