Table 4.
HRs and 95% CI for lung cancer across quintiles of intake of meat mutagens and heme iron in the PLCO Cancer Screening Trial participants (men = 48,229; women = 51,350)
| Men (Cases = 454) | Women (Cases = 328) | |||||||
|---|---|---|---|---|---|---|---|---|
| Q1 | Q3 | Q5 | Ptrend | Q1 | Q3 | Q5 | Ptrend | |
|
Meat mutagens | ||||||||
| Overall mutagenic activity* (revertant colonies/1000 kcal) | ≤ 465 (282) | > 836 to ≤ 1317 (1055) | > 2182 (3186) | ≤ 347 (186) | > 688 to ≤ 1147 (893) | > 2025 (3048) | ||
| Age-and energy-adjusted HR† | 1 | 0.96 (0.72, 1.29) | 1.21 (0.91, 1.62) | 0.22 | 1 | 1.13 (0.80, 1.59) | 1.23 (0.86, 1.76) | 0.50 |
| Multivariable HR‡ | 1 | 0.89 (0.66, 1.20) | 0.98 (0.72, 1.33) | 0.79 | 1 | 1.05 (0.73, 1.50) | 1.02 (0.70, 1.47) | 0.64 |
| MeIQx* (ng/1000 kcal) | ≤ 2.9 (1.7) | > 5.5 to ≤ 8.9 (7.0) | > 15.1 (22.0) | ≤ 2.2 (1.2) | > 4.2 to ≤ 7.1 (5.5) | > 12.2 (17.9) | ||
| Age-and energy-adjusted HR† | 1 | 1.07 (0.79, 1.45) | 1.48 (1.11, 1.98) | 0.01 | 0.88 (0.61, 1.28) | 1.29 (0.91, 1.83) | 0.13 | |
| Multivariable HR‡ | 1 | 0.89 (0.65, 1.22) | 1.01 (0.74, 1.37) | 0.90 | 0.81 (0.55, 1.19) | 0.95 (0.66, 1.38) | 0.70 | |
| DiMeIQx* (ng/1000 kcal) | ≤ 0.10 (0.02) | > 0.29 to ≤ 0.57 (0.42) | > 1.1 (1.70) | ≤ 0.08 (0.02) | > 0.25 to ≤ 0.52 (0.37) | > 1.04 (1.65) | ||
| Age-and energy-adjusted HR† | 1 | 1.05 (0.78, 1.42) | 1.24 (0.92, 1.66) | 0.40 | 0.96 (0.69, 1.35) | 1.07 (0.76, 1.51) | 0.47 | |
| Multivariable HR‡ | 1 | 0.99 (0.73, 1.34) | 1.07 (0.79, 1.44) | 0.94 | 0.99 (0.71, 1.39) | 1.02 (0.72, 1.45) | 0.67 | |
| PhIP* (ng/1000 kcal) | ≤ 8.8 (4.8) | > 17.9 to ≤ 30.8 (23.5) | > 55.8 (86.1) | ≤ 5.8 (2.8) | > 13.8 to ≤ 25.8 (19.0) | > 50.3 (80.5) | ||
| Age- and energy-adjusted HR† | 1 | 0.92 (0.70, 1.22) | 0.93 (0.70, 1.24) | 0.94 | 0.92 (0.65, 1.31) | 1.24 (0.88, 1.74) | 0.22 | |
| Multivariable HR‡ | 1 | 0.94 (0.71, 1.24) | 0.85 (0.63, 1.15) | 0.46 | 1 | 0.86 (0.60, 1.23) | 1.03 (0.72, 1.47) | 0.93 |
| B(a)P* (ng/1000 kcal) | ≤ 1.3 (0.6) | > 3.9 to ≤ 8.3 (5.7) | > 17.5 (28.1) | ≤ 0.9 (0.4) | > 2.6 to ≤ 5.6 (3.9) | > 11.9 (19.8) | ||
| Age-and energy-adjusted HR† | 1 | 0.88 (0.67, 1.17) | 1.03 (0.78, 1.37) | 0.35 | 1 | 0.83 (0.60, 1.15) | 0.71 (0.50, 1.01) | 0.07 |
| Multivariable HR‡ | 1 | 0.95 (0.72, 1.26) | 0.99 (0.74, 1.33) | 0.60 | 0.99 (0.71, 1.36) | 0.72 (0.50, 1.04) | 0.07 | |
| Heme iron* (μg/1000 kcal) | ≤ 106 (72) | > 162 to ≤ 224 (191) | > 317 (411) | ≤ 72 (47) | > 114 to ≤ 160 (136) | > 227 (292) | ||
| Age-and energy-adjusted HR† | 1 | 1.07 (0.78, 1.46) | 1.26 (0.93, 1.72) | 0.24 | 1 | 1.06 (0.75, 1.49) | 1.22 (0.86, 1.71) | 0.11 |
| Multivariable HR‡ | 1 | 0.88 (0.64, 1.22) | 0.91 (0.65, 1.28) | 0.37 | 1 | 0.90 (0.63, 1.28) | 0.89 (0.62, 1.29) | 0.78 |
Range (median).
Cox proportional hazards regression model adjusted for age and energy intake as continuous variable, using age as the underlying time metric.
Cox proportional hazards regression model additionally adjusted for BMI, kg/m2 (<18.5, ≥ 18.5 to <25, ≥ 25 to <30, ≥ 30, missing), race (Caucasian, Black or Hispanic/Asian/Pacific Islander/American Indian/Alaskan native/unknown), education (Less than high school or unknown, High school graduate, College graduate), years since quit smoking (men: quit ≥1 to <5 yrs ago, quit ≥ 5 to < 10 yrs ago, ≥10 to <20 yrs ago, ≥20 yrs ago vs. current and quit <1 yr ago and never smokers; women: quit ≥1 to <10 yrs ago, quit ≥ 10 yrs ago vs. current and quit <1 yr ago and non-smokers), packs of cigarettes smoked per day (men: ≤ 1 packs, > 1 to ≤ 2 packs, > 2 packs/day vs. never smokers; women: ≤ 1 packs, > 1 packs/day vs. never smokers), age started smoking (continuous variable, 0 for never-smokers), number of years smoked (continuous variable, 0 for never-smokers), using pipe or cigar (current vs. former and never user) and intake of alcohol (servings/day) (categorical), energy-adjusted box-cox transformed vegetable and fruit servings, and total fat (continuous).