Table 3.
Associations between caffeinated and decaffeinated coffee consumption and breast cancer risk, overall and by ER/PR status, among 198,404 women, NIH-AARP Diet and Health Study
| Characteristic | All cases (n=9,915) | ER/PR status
|
p-value‡ | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ER+/PR+ (n=2,051) | ER+/PR− (n=425) | ER−/PR+ (n=55) | ER−/PR−(n=453) | |||||||||||||
| n | RR† | (95% CI) | n | RR† | (95% CI) | n | RR† | (95% CI) | n | RR† | (95% CI) | n | RR† | (95% CI) | ||
| Coffee consumption | 0.75 | |||||||||||||||
| Never | 1,106 | 1.00 | referent | 204 | 1.00 | referent | 43 | 1.00 | referent | 5 | 1.00 | referent | 52 | 1.00 | referent | |
| Caffeinated | ||||||||||||||||
| ≤2 cups/week | 343 | 1.01 | (0.90, 1.15) | 84 | 1.33 | (1.03, 1.72) | 21 | 1.59 | (0.94, 2.69) | 3 | 1.79 | (0.42, 7.52) | 21 | 1.28 | (0.77, 2.13) | |
| 3–6 cups/week | 305 | 1.09 | (0.96, 1.24) | 75 | 1.45 | (1.11, 1.89) | 18 | 1.65 | (0.95, 2.88) | 5 | 3.45 | (0.99, 12.08) | 7 | 0.52 | (0.23, 1.14) | |
| 1 cup/day | 1,024 | 1.01 | (0.93, 1.10) | 205 | 1.08 | (0.89, 1.31) | 35 | 0.87 | (0.55, 1.36) | 2 | 0.39 | (0.08, 2.04) | 44 | 0.93 | (0.62, 1.40) | |
| 2–3 cups/day | 2,580 | 1.00 | (0.93, 1.07) | 528 | 1.10 | (0.93, 1.30) | 117 | 1.11 | (0.77, 1.59) | 13 | 1.02 | (0.36, 2.93) | 103 | 0.86 | (0.61, 1.22) | |
| 4+ cups/day | 885 | 0.98 | (0.90, 1.08) | 175 | 1.09 | (0.88, 1.34) | 37 | 0.98 | (0.62, 1.55) | 5 | 1.38 | (0.39, 4.88) | 44 | 1.09 | (0.72, 1.65) | |
| p-value for trend | 0.48 | 0.82 | 0.59 | 0.96 | 0.98 | |||||||||||
| Decaffeinated | ||||||||||||||||
| ≤2 cups/week | 654 | 1.11 | (1.01, 1.22) | 130 | 1.18 | (0.95, 1.47) | 23 | 0.98 | (0.59, 1.62) | 4 | 1.39 | (0.37, 5.19) | 38 | 1.37 | (0.90, 2.09) | |
| 3–6 cups/week | 342 | 0.98 | (0.87, 1.10) | 79 | 1.22 | (0.94, 1.58) | 11 | 0.80 | (0.41, 1.55) | 3 | 1.74 | (0.41, 7.32) | 19 | 1.16 | (0.68, 1.96) | |
| 1 cup/day | 732 | 1.02 | (0.93, 1.13) | 151 | 1.14 | (0.93, 1.41) | 25 | 0.89 | (0.54, 1.46) | 4 | 1.19 | (0.32, 4.47) | 27 | 0.83 | (0.52, 1.33) | |
| 2–3 cups/day | 1,250 | 1.10 | (1.01, 1.19) | 282 | 1.33 | (1.11, 1.60) | 65 | 1.42 | (0.96, 2.10) | 8 | 1.49 | (0.48, 4.63) | 61 | 1.20 | (0.82, 1.75) | |
| 4+ cups/day | 282 | 1.00 | (0.88, 1.15) | 61 | 1.18 | (0.88, 1.57) | 11 | 0.95 | (0.49, 1.85) | 0 | --- | 14 | 1.13 | (0.62, 2.05) | ||
| p-value for trend | 0.40 | 0.04 | 0.16 | 0.65 | 0.74 | |||||||||||
| Unknown caffeine status | 412 | 1.09 | (0.97, 1.22) | 77 | 1.12 | (0.86, 1.46) | 19 | 1.27 | (0.73, 2.18) | 3 | 1.81 | (0.43, 7.63) | 23 | 1.28 | (0.78, 2.10) | |
†
Relative risk adjusting for age (continuous), race/ethnicity, education, BMI (kg/m2), smoking status and dose, alcohol, proportion of total energy from fat (quintiles), age at first live birth, menopausal hormone therapy use, history of breast biopsy, and family history of breast cancer.
‡
p-value for heterogeneity obtained through multivariate polytomous logistic regression models where the referent category is ER+/PR+ breast cancer. ER, estrogen receptor; PR, progesterone receptor