TABLE 5.
Association between dietary ω-3 PUFA intake and endometrial cancer risk stratified by BMI (in kg/m2) (n = 87,360)1
| Energy-adjusted quintiles of fatty acid intake |
|||||||
| 1 | 2 | 3 | 4 | 5 | P-trend | ||
| ω-3 Fatty acids | |||||||
| EPA + DPA + DHA, mg/d | ≤56.8 | 56.9–91.2 | 91.3–133.9 | 134.0–205.2 | >205.2 | ||
| BMI <25, n cases | 89 | 80 | 80 | 73 | 70 | ||
| HR (95% CI) | 1.00 (reference) | 0.97 (0.69, 1.37) | 0.83 (0.58, 1.18) | 0.69 (0.48, 0.99) | 0.59 (0.40, 0.86) | 0.001 | |
| BMI ≥25, n cases | 176 | 155 | 187 | 168 | 165 | ||
| HR (95% CI) | 1.00 (reference) | 0.96 (0.75, 1.25) | 1.12 (0.88, 1.44) | 1.02 (0.80, 1.32) | 0.95 (0.74, 1.24) | 0.907 | |
| P-interaction | 0.013 | ||||||
| EPA (20:5ω-3), mg/d | ≤15.6 | 15.7–27.4 | 27.5–41.3 | 41.4–63.6 | >63.6 | ||
| BMI <25, n cases | 88 | 78 | 81 | 78 | 67 | ||
| HR (95% CI) | 1.00 (reference) | 0.95 (0.68, 1.34) | 0.80 (0.57, 1.15) | 0.72 (0.50, 1.03) | 0.56 (0.38, 0.83) | 0.001 | |
| BMI ≥25, n cases | 172 | 171 | 161 | 187 | 160 | ||
| HR (95% CI) | 1.00 (reference) | 1.15 (0.90, 1.48) | 1.02 (0.79, 1.33) | 1.17 (0.91, 1.50) | 0.97 (0.75, 1.25) | 0.881 | |
| P-interaction | 0.013 | ||||||
| DPA (22:5ω-3), mg/d | ≤6.8 | 6.9–10.7 | 10.8–15.2 | 15.3–22.2 | >22.2 | ||
| BMI <25, n cases | 87 | 79 | 88 | 70 | 68 | ||
| HR (95% CI) | 1.00 (reference) | 0.89 (0.63, 1.25) | 0.93 (0.66, 1.30) | 0.61 (0.42, 0.90) | 0.70 (0.48, 1.02) | 0.012 | |
| BMI ≥25, n cases | 180 | 171 | 160 | 170 | 170 | ||
| HR (95% CI) | 1.00 (reference) | 1.09 (0.85, 1.39) | 0.94 (0.73, 1.21) | 0.93 (0.72, 1.20) | 0.93 (0.72, 1.20) | 0.297 | |
| P-interaction | 0.143 | ||||||
| DHA (22:6ω-3), mg/d | ≤32.8 | 32.9–51.9 | 52.0–76.8 | 76.9–121.0 | >121.0 | ||
| BMI <25, n cases | 96 | 81 | 71 | 69 | 75 | ||
| HR (95% CI) | 1.00 (reference) | 0.86 (0.61, 1.20) | 0.68 (0.48, 0.97) | 0.57 (0.40, 0.82) | 0.53 (0.37, 0.77) | <0.001 | |
| BMI ≥25, n cases | 185 | 147 | 189 | 167 | 163 | ||
| HR (95% CI) | 1.00 (reference) | 0.92 (0.71, 1.19) | 1.12 (0.88, 1.43) | 0.97 (0.76, 1.25) | 0.94 (0.73, 1.21) | 0.797 | |
| P-interaction | 0.003 | ||||||
| ALA (18:3ω-3), mg/d | ≤921.6 | 921.7–1130.6 | 1130.7–1333.1 | 1333.2–1640.0 | >1640.0 | ||
| BMI <25, n cases | 87 | 74 | 76 | 79 | 76 | ||
| HR (95% CI) | 1.00 (reference) | 0.95 (0.66, 1.35) | 0.98 (0.68, 1.41) | 1.15 (0.81, 1.64) | 1.13 (0.78, 1.62) | 0.311 | |
| BMI ≥25, n cases | 195 | 169 | 144 | 159 | 184 | ||
| HR (95% CI) | 1.00 (reference) | 0.93 (0.73, 1.19) | 0.75 (0.58, 0.98) | 0.89 (0.70, 1.15) | 0.89 (0.70, 1.14) | 0.352 | |
| P-interaction | 0.310 | ||||||
| ω-6 Fatty acids | |||||||
| LA + AA, mg/d | ≤8328.5 | 8328.6–10,061.7 | 10,061.8–11,539.7 | 11,539.8–13,494.5 | >13,494.5 | ||
| BMI <25, n cases | 85 | 85 | 71 | 75 | 76 | ||
| HR (95% CI) | 1.00 (reference) | 0.94 (0.66, 1.33) | 1.00 (0.69, 1.43) | 1.21 (0.84, 1.75) | 1.46 (1.01, 2.10) | 0.024 | |
| BMI ≥25, n cases | 182 | 148 | 158 | 164 | 199 | ||
| HR (95% CI) | 1.00 (reference) | 0.75 (0.58, 0.97) | 0.82 (0.63, 1.05) | 0.82 (0.64, 1.06) | 0.95 (0.75, 1.21) | 0.999 | |
| P-interaction | 0.159 | ||||||
| LA (18:2ω-6), mg/d | ≤8235.9 | 8236.0–9962.1 | 9962.2–11,438.1 | 11,438.2–13,391.3 | >13,391.3 | ||
| BMI <25, n cases | 83 | 87 | 71 | 76 | 75 | ||
| HR (95% CI) | 1.00 (reference) | 0.93 (0.66, 1.32) | 0.99 (0.69, 1.42) | 1.22 (0.84, 1.75) | 1.41 (0.98, 2.04) | 0.032 | |
| BMI ≥25, n cases | 184 | 146 | 159 | 163 | 199 | ||
| HR (95% CI) | 1.00 (reference) | 0.72 (0.56, 0.93) | 0.81 (0.63, 1.05) | 0.80 (0.62, 1.04) | 0.94 (0.74, 1.20) | 0.957 | |
| P-interaction | 0.173 | ||||||
| AA (20:4ω-6), mg/d | ≤61.5 | 61.6–80.9 | 81.0–99.8 | 99.9–127.5 | >127.5 | ||
| BMI <25, n cases | 115 | 91 | 80 | 58 | 48 | ||
| HR (95% CI) | 1.00 (reference) | 0.73 (0.53, 1.01) | 0.77 (0.55, 1.07) | 0.55 (0.38, 0.81) | 0.67 (0.46, 0.99) | 0.007 | |
| BMI ≥25, n cases | 188 | 145 | 148 | 166 | 204 | ||
| HR (95% CI) | 1.00 (reference) | 0.81 (0.63, 1.04) | 0.78 (0.60,1.00) | 0.80 (0.62,1.02) | 0.80 (0.63,1.02) | 0.105 | |
| P-interaction | 0.130 | ||||||
| ω-3:ω-6 | |||||||
| Ratio of EPA + DPA + DHA to LA + AA, mg/d | ≤0.005 | 0.006–0.008 | 0.009–0.013 | 0.014–0.021 | >0.021 | ||
| BMI <25, n cases | 82 | 85 | 72 | 76 | 77 | ||
| HR (95% CI) | 1.00 (reference) | 1.09 (0.77, 1.55) | 0.81 (0.56, 1.17) | 0.67 (0.46, 0.97) | 0.66 (0.46, 0.97) | 0.002 | |
| BMI ≥25, n cases | 184 | 159 | 169 | 181 | 158 | ||
| HR (95% CI) | 1.00 (reference) | 0.92 (0.71, 1.18) | 0.95 (0.74, 1.22) | 1.09 (0.85, 1.39) | 0.90 (0.70, 1.17) | 0.916 | |
| P-interaction | 0.030 | ||||||
HRs (95% CIs) were derived from Cox proportional hazards regression models adjusted for age (time variable), clinical trial/observational study intervention assignment, US region, race, education, BMI, smoking, alcohol, physical activity, age at menarche, age at first birth, age at menopause, parity, duration of combined menopausal hormone therapy, duration of estrogen-alone hormone therapy, duration of oral contraceptive use, oophoerectomy status, family history of endometrial cancer, history of diabetes, and total energy. P-trend values were calculated by treating categorical exposure variables as continuous in regression models. P-interaction values were calculated by using the likelihood ratio test. AA, arachidonic acid; ALA, α-linolenic acid; DPA, docosapentaenoic acid; LA, linoleic acid.