TABLE 3.
Pooled multivariate RRs (95% CIs) of breast cancer for dietary carotenoid intakes jointly by ER and PR status in the Pooling Project of Prospective Studies of Diet and Cancer1
| RR (95% CI) |
Continuous3 |
||||||||
| Carotenoids | Quintile 1 | Quintile 2 | Quintile 3 | Quintile 4 | Quintile 5 | P-trend2 | RR (95% CI) | P (test for between-studies heterogeneity)4 | P (test for common effects by hormone receptor status)5 |
| α-Carotene | |||||||||
| ER+ PR+ | 1 | 0.99 (0.94, 1.04) | 1.05 (0.99, 1.11) | 1.02 (0.96, 1.07) | 1.02 (0.97, 1.08) | 0.28 | 1.01 (0.99, 1.04) | 0.71 | |
| ER+ PR− | 1 | 1.09 (0.98, 1.22) | 1.05 (0.94, 1.17) | 1.04 (0.93, 1.16) | 1.06 (0.91, 1.25) | 0.53 | 1.03 (0.94, 1.12) | 0.01 | |
| ER− PR+6 | 1 | 0.69 (0.53, 0.89) | 0.73 (0.55, 0.95) | 0.75 (0.57, 0.98) | 0.64 (0.47, 0.86) | 0.04 | 0.86 (0.74, 1.00) | 0.50 | 0.16 |
| ER− PR− | 1 | 0.94 (0.84, 1.05) | 0.91 (0.79, 1.03) | 0.90 (0.80, 1.02) | 0.90 (0.80, 1.01) | 0.18 | 0.98 (0.92, 1.04) | 0.22 | |
| β-Carotene | |||||||||
| ER+ PR+ | 1 | 1.04 (0.97, 1.11) | 1.04 (0.98, 1.10) | 1.03 (0.97, 1.09) | 1.03 (0.98, 1.09) | 0.53 | 1.01 (0.98, 1.04) | 0.49 | |
| ER+ PR− | 1 | 1.01 (0.90, 1.13) | 1.06 (0.94, 1.18) | 1.08 (0.97, 1.21) | 1.05 (0.91, 1.22) | 0.55 | 1.01 (0.92, 1.13) | 0.02 | |
| ER− PR+6 | 1 | 0.72 (0.53, 0.97) | 0.90 (0.69, 1.16) | 0.81 (0.62, 1.06) | 0.70 (0.51, 0.96) | 0.10 | 0.89 (0.75, 1.05) | 0.64 | 0.12 |
| ER− PR− | 1 | 0.96 (0.87, 1.06) | 0.91 (0.82, 1.01) | 0.89 (0.78, 1.02) | 0.87 (0.78, 0.96) | 0.01 | 0.94 (0.88, 1.01) | 0.45 | |
| β-Cryptoxanthin | |||||||||
| ER+ PR+ | 1 | 0.98 (0.93, 1.03) | 1.00 (0.94, 1.06) | 0.99 (0.95, 1.04) | 0.96 (0.92, 1.01) | 0.28 | 1.00 (0.97, 1.03) | 0.17 | |
| ER+ PR− | 1 | 0.98 (0.85, 1.13) | 1.00 (0.89, 1.13) | 1.00 (0.88, 1.15) | 0.91 (0.80, 1.05) | 0.13 | 0.97 (0.93, 1.00) | 0.54 | |
| ER− PR+6 | 1 | 0.94 (0.72, 1.23) | 0.94 (0.69, 1.27) | 0.90 (0.63, 1.26) | 0.78 (0.59, 1.03) | 0.08 | 0.94 (0.86, 1.02) | 0.65 | 0.24 |
| ER− PR− | 1 | 0.97 (0.88, 1.08) | 0.96 (0.86, 1.06) | 0.99 (0.88, 1.10) | 0.95 (0.84, 1.07) | 0.13 | 0.97 (0.94, 1.01) | 0.67 | |
| Lutein/zeaxanthin | |||||||||
| ER+ PR+ | 1 | 1.00 (0.93, 1.08) | 1.06 (1.01, 1.11) | 1.04 (0.98, 1.10) | 0.99 (0.93, 1.07) | 0.63 | 1.01 (0.98, 1.04) | 0.32 | |
| ER+ PR− | 1 | 1.08 (0.97, 1.21) | 1.03 (0.92, 1.15) | 1.05 (0.91, 1.22) | 1.07 (0.93, 1.23) | 0.69 | 1.04 (0.98, 1.10) | 0.29 | |
| ER− PR+6 | 1 | 0.82 (0.60, 1.13) | 0.72 (0.55, 0.95) | 0.76 (0.58, 0.99) | 0.72 (0.51, 1.02) | 0.09 | 0.94 (0.83, 1.07) | 0.86 | 0.09 |
| ER− PR− | 1 | 0.95 (0.86, 1.05) | 0.89 (0.80, 0.99) | 0.89 (0.79, 1.01) | 0.89 (0.81, 0.99) | 0.16 | 0.96 (0.91, 1.01) | 0.91 | |
| Lycopene | |||||||||
| ER+ PR+ | 1 | 0.99 (0.93, 1.06) | 1.02 (0.95, 1.08) | 1.02 (0.96, 1.09) | 1.00 (0.93, 1.08) | 0.63 | 1.00 (0.98, 1.02) | 0.84 | |
| ER+ PR− | 1 | 0.91 (0.79, 1.05) | 0.97 (0.86, 1.10) | 0.96 (0.85, 1.08) | 0.96 (0.84, 1.10) | 0.99 | 1.04 (0.98, 1.10) | 0.26 | |
| ER− PR+6 | 1 | 0.76 (0.58, 1.00) | 0.91 (0.59, 1.39) | 0.94 (0.66, 1.36) | 0.73 (0.55, 0.97) | 0.15 | 0.90 (0.75, 1.07) | 0.40 | 0.22 |
| ER− PR− | 1 | 0.95 (0.86, 1.05) | 0.92 (0.82, 1.03) | 0.91 (0.82, 1.00) | 0.95 (0.85, 1.07) | 0.37 | 0.99 (0.95, 1.04) | 0.57 | |
Adjusted for ethnicity (white, African American, Hispanic, Asian, other), family history of breast cancer (yes, no), personal history of benign breast disease (yes, no), alcohol consumption (nondrinkers; >0 to <5, 5 to <15, 15 to <30, or ≥30 g/d), smoking status (never, past, current), education (<high school, high school, >high school), physical activity (low, medium, high), age at menarche (<11, 11–12, 13–14, ≥15 y), BMI (in kg/m2; <23, 23 to <25, 25 to <30, ≥30), height (<1.60, 1.60 to <1.65, 1.65 to <1.70, 1.70 to <1.75, ≥1.75 m), oral contraceptive use (never, ever), menopausal status (premenopausal, postmenopausal, never user of hormone replacement therapy, past user of hormone replacement therapy, current user of hormone replacement therapy), energy intake (kcal/d, continuous), combination between parity (0, 1–2, ≥3), and age of first birth (≤25, >25 y); age in years and year of questionnaire return were included as stratification variables. The study-specific median intakes for each carotenoid for quintile 1 and quintile 5 are shown in Table 1 as 10th and 90th percentiles. ER, estrogen receptor; ER+, estrogen receptor positive; ER−, estrogen receptor negative; PR, progesterone receptor; PR+, progesterone receptor positive; PR−, progesterone receptor negative.
Calculated by using the Wald test statistic.
The incremental units were based on the median of the difference between the 90th and 10th percentile intakes of each carotenoid across studies. The increments are 1200 μg/d for α-carotene, 5000 μg/d for β-carotene, 200 μg/d for β-cryptoxanthin, 3500 μg/d for lutein/zeaxanthin, and 6000 μg/d for lycopene. There is ∼1200 μg α-carotene in two-fifths of a carrot, 5000 μg β-carotene in two-thirds of a carrot, 200 μg β-cryptoxanthin in 2 oranges, 3500 μg lutein/zeaxanthin in 1.5 cups (250 g) broccoli, and 6000 μg lycopene in 1.5 oz (43 g) tomato sauce.
Calculated by using the Q test statistic.
Calculated by using a contrast test.
The Beta-Carotene and Retinol Efficacy Trial; the Black Women's Health Study; CLUE II: Campaign Against Cancer and Heart Disease; the Canadian National Breast Screening Study; the Japan Public Health Center–based Study Cohort I; the Netherlands Cohort Study; the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial; and the Women's Health Study were excluded because the number of cases of ER− PR+ breast cancer in each of these studies was <25.