Table 6.

Risk of premenopausal breast cancer in women with and without family history of breast cancer according to body size and shape at cohort enrolment

Family History of Breast Cancer
No Family History of Breast Cancer
No. of Cases/Non-casesMultivariate RR*95% CINo. of Cases/Non-casesMultivariate RR*95% CI
BMI (kg/m2) at cohort enrolment
    <2014/6161.400.76-2.57109/12,7381.170.95-1.46
    20-24.946/2,9411.0 (reference)420/58,0801.0 (reference)
    25-29.911/7980.920.47-1.7993/16,5130.770.61-0.98
    ≥304/2260.960.30-3.1319/4,3580.580.36-0.95
P for linear trend0.370.0004
P for interaction between BMI and presence of family history of breast cancer = 0.40
  • * 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.