Table 3.

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

BMI per 4 kg/m2 incrementP for between studies-heterogeneityBMI, categorical (kg/m2)
PtrendP for between studies-heterogeneity*
<2323 to <2525 to <2727 to <30≥30
All females
    n cases718441316285276
    Age-adjusted RR (95% CI)0.99 (0.94-1.05)0.101 (Reference)0.89 (0.79-1.01)0.89 (0.76-1.03)0.88 (0.76-1.02)0.98 (0.84-1.14)0.600.31
    Multivariate adjusted RR,,§ (95% CI)1.01 (0.95-1.07)0.051 (Reference)0.91 (0.80-1.03)0.91 (0.78-1.07)0.91 (0.78-1.05)1.03 (0.86-1.22)0.900.21
Postmenopausal females (at baseline)
    n cases426291222206191
    Age-adjusted RR (95% CI)1.00 (0.94-1.07)0.151 (Reference)0.90 (0.77-1.05)0.92 (0.78-1.09)0.93 (0.78-1.10)1.02 (0.83-1.25)0.910.24
    Multivariate adjusted RR,§ (95% CI)1.02 (0.95-1.08)0.191 (Reference)0.91 (0.78-1.06)0.95 (0.80-1.13)0.96 (0.80-1.14)1.07 (0.87-1.33)0.530.22
Premenopausal females (at diagnosis)
    n cases6434141422
    Age-adjusted RR (95% CI)1.10 (0.95-1.28)0.341 (Reference)1.25 (0.81-1.92)0.95 (0.52-1.71)1.23 (0.59-2.53)1.62** (0.97-2.70)0.210.53
    Multivariate adjusted RR (95% CI)1.12 (0.96-1.31)0.321 (Reference)1.29 (0.83-2.00)0.95 (0.50-1.81)1.28 (0.59-2.79)1.72** (1.02-2.89)0.130.49
All females, serous carcinoma††
    n cases352209145146132
    Age-adjusted RR (95% CI)0.98 (0.93-1.04)0.601 (Reference)0.87 (0.72-1.05)0.85 (0.69-1.03)0.92 (0.75-1.12)0.91 (0.74-1.12)0.400.77
    Multivariate adjusted RR,,§ (95% CI)1.00 (0.94-1.06)0.551 (Reference)0.88 (0.72-1.06)0.86 (0.70-1.04)0.93 (0.76-1.14)0.95 (0.77-1.17)0.640.78
All females, endometrioid carcinoma††,‡‡<2323-<25≥25
    n cases936298
    Age-adjusted RR (95% CI)0.97 (0.81-1.16)0.021 (Reference)1.04 (0.71-1.53)0.88 (0.59-1.30)0.560.11
    Multivariate adjusted RR,,§ (95% CI)0.99 (0.82-1.19)0.021 (Reference)1.06 (0.72-1.56)0.92 (0.62-1.36)0.740.16
All females, mucinous carcinoma††,‡‡,§§
    n cases402555
    Age-adjusted RR (95% CI)1.02 (0.85-1.22)0.481 (Reference)0.83 (0.50-1.36)0.97 (0.65-1.47)0.890.56
    Multivariate adjusted RR,,§ (95% CI)1.03 (0.84-1.27)0.321 (Reference)0.84 (0.51-1.38)1.02 (0.66-1.57)0.740.45
  • * Based on the highest category versus the reference category.

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

  • Multivariate RRs were also adjusted for menopausal status at baseline.

  • § Multivariate RRs were also adjusted for hormone replacement therapy use among postmenopausal women (never, past, current).

  • 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.

  • Only Canadian National Breast Screening Study, New York University Women's Health Study, NHSa, NHSb, and NHS II (cohorts with >10 cases) were included in these analyses.

  • ** New York University Women's Health Study was not included in the category ≥30 because there were no cases in that category. The participants who were not cases who would have been in this highest category were included in the next highest category (25 to <30 kg/m2).

  • †† Adventist Health Study was not included in these analyses because information on histologic subtypes was not available.

  • ‡‡ New York State Cohort and New York University Women's Health Study were not included in these analyses because each study had <10 cases.

  • §§ Breast Cancer Detection Demonstration Project Follow-up Study, NHS II, and Women's Health Study were not included because each study had <10 cases.