Table 2.
Relative risk (and 95% confidence interval) of breast, endometrial, and ovarian cancers by quintile of calorie-adjusted acrylamide intake, 1980–2006
| Quintile of calorie-adjusted acrylamide intake |
||||||
|---|---|---|---|---|---|---|
| Q1 (low) | Q2 | Q3 | Q4 | Q5 (high) | p-value | |
| Median intake (mcg/d) | 8.7 | 12.7 | 15.7 | 19.0 | 25.1 | for trend |
| BREAST CANCER | ||||||
| Num. cases | 1282 | 1280 | 1331 | 1287 | 1121 | |
| Person-years | 405,391 | 404,518 | 404,349 | 404,769 | 405,644 | |
| Age-adjusted RR* | 1.00 | 0.94 (0.87–1.02) | 0.99 (0.92–1.07) | 0.99 (0.91–1.07) | 0.94 (0.87–1.02) | 0.36 |
| Multivariable RR† | 1.00 | 0.93 (0.86–1.01) | 0.98 (0.91–1.06) | 0.98 (0.90–1.06) | 0.95 (0.87–1.03) | 0.50 |
| Never smokers only | ||||||
| Num. cases | 652 | 610 | 582 | 516 | 392 | |
| Person-years | 210,666 | 198,085 | 187,783 | 171,665 | 151,532 | |
| Age-adjusted RR* | 1.00 | 0.94 (0.84–1.05) | 0.96 (0.86–1.08) | 0.96 (0.85–1.08) | 0.90 (0.80–1.03) | 0.21 |
| Multivariable RR† | 1.00 | 0.91 (0.81–1.02) | 0.93 (0.83–1.05) | 0.94 (0.84–1.06) | 0.89 (0.78–1.02) | 0.18 |
| ENDOMETRIAL CANCER | ||||||
| Num. cases | 88 | 100 | 106 | 102 | 88 | |
| Person-years | 277,776 | 277,073 | 276,839 | 277,409 | 277,789 | |
| Age-adjusted RR* | 1.00 | 1.07 (0.80–1.43) | 1.17 (0.88–1.56) | 1.15 (0.86–1.54) | 1.12 (0.83–1.52) | 0.41 |
| Multivariable RR‡ | 1.00 | 1.12 (0.83–1.50) | 1.31 (0.97–1.77) | 1.35 (0.99–1.84) | 1.41 (1.01–1.97) | 0.03 |
| Never smokers only | ||||||
| Num. cases | 53 | 47 | 59 | 56 | 42 | |
| Person-years | 144,400 | 135,320 | 128,534 | 116,601 | 102,813 | |
| Age-adjusted RR* | 1.00 | 0.93 (0.63–1.39) | 1.30 (0.89–1.90) | 1.37 (0.93–2.01) | 1.31 (0.86–2.00) | 0.06 |
| Multivariable RR‡ | 1.00 | 0.97 (0.64–1.46) | 1.35 (0.90–2.02) | 1.47 (0.97–2.24) | 1.43 (0.90–2.28) | 0.04 |
| OVARIAN CANCER | ||||||
| Num. cases | 87 | 75 | 95 | 81 | 78 | |
| Person-years | 246,187 | 245,523 | 245,327 | 245,667 | 246,155 | |
| Age-adjusted RR* | 1.00 | 0.85 (0.62–1.16) | 1.10 (0.81–1.47) | 0.95 (0.70–1.29) | 1.00 (0.73–1.37) | 0.78 |
| Multivariable RR§ | 1.00 | 0.93 (0.68–1.29) | 1.29 (0.94–1.76) | 1.17 (0.84–1.64) | 1.25 (0.88–1.77) | 0.12 |
| Never smokers only | ||||||
| Num. cases | 40 | 38 | 31 | 24 | 23 | |
| Person-years | 126,888 | 118,416 | 112,475 | 101,849 | 91,082 | |
| Age-adjusted RR* | 1.00 | 1.03 (0.65–1.63) | 0.92 (0.57–1.48) | 0.82 (0.49–1.37) | 0.92 (0.54–1.55) | 0.53 |
| Multivariable RR§ | 1.00 | 1.17 (0.72–1.88) | 1.04 (0.63–1.74) | 1.11 (0.63–1.94) | 1.19 (0.66–2.15) | 0.63 |
Age-adjusted models are adjusted for age in months and calendar year.
Breast cancer multivariable models additionally adjusted for: smoking (never, past <25 cig/d, past 25+ cig/d, current <25 cig/d, current 25+ cig/d), BMI (<18.5, 18.5 to <20, 20 to <22.5, 22.5 to <25, 25 to <30, 30+), height (quartiles), menopausal status/age at menopause/PMH use (premenopausal, uncertain status, postmenopausal: age at menopause <45, 45–52, or >52 AND PMH use never, former, current <5 years, or current 5+ years), parity and age at first birth (nulliparous, parity 1–2 and age first birth <25, parity 1–2 age first birth 25-<30, parity 1–2 age first birth 30+, parity 3–4 age first birth <25, parity 3–4 age first birth 25-<30, parity 3–4 age first birth 30+, parity 5+ age first birth <25, parity 5+ age first birth 25+) family history of breast cancer (yes/no), benign breast disease (yes/no), age at menarche (<13, 13, 14+), physical activity (<=18 met-h/wk, >18 met-h/wk), folate, glycemic index, and animal fat intake (quintiles), alcohol (continuous, g/day), energy intake (continuous, kcal/d).
Endometrial cancer multivariable models additionally adjusted for: smoking (see categories for breast cancer), BMI (<20, 20-<21, 21-<22, 22-<23, 23-<24, 24-<25, 25-<27, 27-<29, 29-<30, 30-<32, 32-<35, 35-<40, 40+), age at menarche (<13, 13, 14+), menopausal status/age at menopause/PMH use (see categories for breast cancer), parity (nulliparous, 1–2, 3–4, 5+), oral contraceptive use (never, 0–3 years of use, >3-<5 years, 5+ years of use), high blood pressure (yes/no), diabetes (yes/no), physical activity (<=18 met-h/wk, >18 met-h/wk), caffeine intake (quintiles), energy intake (continuous, kcal/d).
Ovarian cancer multivariable models additionally adjusted for: smoking (see categories for breast cancer), BMI (see categories for breast cancer), parity (see categories for endometrial cancer), oral contraceptive use (see categories for endometrial cancer), menopausal status and PMH use (premenopausal, uncertain status, postmenopausal and never used PMH, postmenopausal and former PMH, postmenopausal and current PMH use), tubal ligation (yes/no), physical activity (<=18 met-h/wk, >18 met-h/wk), caffeine intake (quintiles), energy intake (continuous, kcal/d).