Table 4.

Association between environmental and genetic factors and ovarian cancer risk in a multiplicative joint effects model

InvasiveSerousMucinousEndometrioidClear cell
ORa (95% CI)PORa 95% CIPORa 95% CIPORa 95% CIPORa 95% CIPPhet across histology
Endometriosis
 Yes vs. no1.53 (1.30–1.81)<0.0011.17 (0.95–1.44)0.1431.54 (0.86–2.74)0.1452.40 (1.78–3.23)<0.0013.59 (2.50–5.15)<0.001<0.001
First-degree family history
 Yes vs. no2.09 (1.70–2.57)<0.0012.29 (1.81–2.89)<0.0012.40 (1.25–4.61)0.0091.96 (1.28–3.00)0.0022.15 (0.94–4.92)0.0710.929
Oral contraceptive use
 1–1.99 years vs. never0.70 (0.59–0.83)<0.0010.80 (0.65–0.98)0.0310.75 (0.36–1.57)0.4510.64 (0.45–0.92)0.0160.76 (0.46–1.24)0.2720.798
 2–4.99 years vs. never0.57 (0.50–0.65)<0.0010.65 (0.56–0.77)<0.0010.56 (0.35–0.90)0.0160.45 (0.34–0.60)<0.0010.55 (0.37–0.83)0.0040.167
 5–9.99 years vs. never0.48 (0.42–0.55)<0.0010.53 (0.45–0.62)<0.0010.68 (0.46–1.01)0.0540.41 (0.31–0.54)<0.0010.40 (0.27–0.58)<0.0010.097
 10+ years vs. never0.34 (0.30–0.39)<0.0010.39 (0.33–0.46)<0.0010.48 (0.32–0.72)<0.0010.28 (0.21–0.38)<0.0010.28 (0.18–0.44)<0.0010.083
Tubal ligation
 Yes vs. no0.74 (0.67–0.83)<0.0010.84 (0.74–0.95)0.0070.65 (0.42–0.99)0.0430.57 (0.44–0.73)<0.0010.68 (0.47–0.99)0.0460.041
Parity
 1 birth vs. no births0.76 (0.66–0.88)<0.0010.89 (0.75–1.06)0.1750.76 (0.49–1.17)0.2140.69 (0.53–0.91)0.0090.39 (0.26–0.58)<0.0010.002
 2 or more births vs. no births0.58 (0.51–0.65)<0.0010.66 (0.58–0.76)<0.0010.52 (0.37–0.73)<0.0010.42 (0.34–0.53)<0.0010.25 (0.18–0.33)<0.001<0.001
Risk score quartile
 Second vs. first quartile1.25 (1.12–1.40)<0.0011.33 (1.15–1.53)<0.0011.72 (1.20–2.48)0.0041.25 (0.98–1.59)0.0681.19 (0.84–1.69)0.3290.463
 Third vs. first quartile1.29 (1.16–1.44)<0.0011.36 (1.19–1.56)<0.0011.31 (0.91–1.90)0.1511.13 (0.89–1.43)0.3211.20 (0.86–1.69)0.2890.577
 Fourth vs. first quartile1.65 (1.48–1.84)<0.0011.85 (1.62–2.11)<0.0011.76 (1.24–2.48)0.0011.64 (1.31–2.05)<0.0011.59 (1.15–2.21)0.0060.728
  • aOR conditioned on age and race/ethnicity, individual models by site; estimate derived from meta-analysis of individual site models.