Table 4.

Pooled RRs and 95% CIs for ovarian cancer according to BMI in early adulthood, the Pooling Project of Prospective Studies of Diet and Cancer

BMI in early adulthood per 4 kg/m2 incrementP for between studies-heterogeneityBMI in early adulthood categorical (kg/m2)
PtrendP for between studies-heterogeneity*
<18.518.5 to <2121-<2323-<25≥25
All females,
    n cases17554334814396
    Age-adjusted RR (95% CI)1.01 (0.88-1.17)0.0021 (Reference)1.01 (0.92-1.30)1.09 (0.89-1.34)1.01 (0.76-1.34)1.04 (0.72-1.50)0.900.09
    Multivariate adjusted RR (95% CI)1.00 (0.87-1.15)0.0041 (Reference)1.09 (0.92-1.30)1.08 (0.88-1.33)0.99 (0.74-1.33)1.01 (0.72-1.43)0.950.14
    Multivariate adjusted RR§ (95% CI)0.98 (0.87-1.11)0.051 (Reference)1.09 (0.92-1.30)1.08 (0.88-1.31)0.99 (0.74-1.33)0.97 (0.73-1.30)0.710.41
Postmenopausal females
    n cases13138926210663
    Age-adjusted RR (95% CI)1.00 (0.86-1.16)0.021 (Reference)1.15 (0.93-1.43)1.17 (0.92-1.49)1.09 (0.73-1.62)1.06 (0.90-1.00)0.970.15
    Multivariate adjusted RR (95% CI)0.99 (0.85-1.15)0.031 (Reference)1.14 (0.93-1.40)1.17 (0.91-1.50)1.11 (0.72-1.70)1.03 (0.70-1.52)0.920.21
  • * Based on the highest category versus the reference category.

  • Multivariate RRs were adjusted for age at menarche (<13, 13, >13 y), menopausal status at baseline, oral contraceptive use (ever, never), hormone replacement therapy use among postmenopausal women (never, past, current), parity (0, 1, 2, >2), smoking status (never, past, current), physical activity (low, medium, high), and energy intake (continuously), modeled identically across studies.

  • Only Canadian National Breast Screening Study, Cancer Prevention Study II Nutrition Cohort, Iowa Women's Health Study, The Netherlands Cohort Study, NHSa, NHSb, and NHS II were included in these analyses; other studies did not have information regarding body mass at early adulthood.

  • § Multivariate RRs were also adjusted for BMI at baseline (continuously).

  • NHS II was not included in these analyses because this study has <10 cases and New York State Cohort was not included because this study had no information on menopausal status.