Table 4.
Multivariable RRs of Postmenopausal Breast Cancer by Hormone Receptor Status According to Acetaminophen Use in the Nurses' Health Study (1990 to 2008)
| Details of Use | Total Breast Cancer |
ER Positive PR Positive |
ER Positive PR Negative |
ER Negative PR Negative |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No. of Patients | RR* | 95% CI | No. of Patients | RR* | 95% CI | No. of Patients | RR* | 95% CI | No. of Patients | RR* | 95% CI | |
| Acetaminophen use | ||||||||||||
| Nonuser | 1,680 | 1.0 | Reference | 924 | 1.0 | Reference | 234 | 1.0 | Reference | 249 | 1.0 | Reference |
| Past | 1,216 | 0.93 | 0.86 to 1.01 | 673 | 0.92 | 0.83 to 1.02 | 153 | 0.90 | 0.73 to 1.12 | 175 | 0.88 | 0.72 to 1.08 |
| Current | 1,199 | 0.89 | 0.83 to 0.96 | 623 | 0.85 | 0.77 to 0.95 | 179 | 1.01 | 0.83 to .123 | 157 | 0.81 | 0.66 to 1.00 |
| Frequency, days per week | ||||||||||||
| Nonuser | 1,680 | 1.0 | Reference | 924 | 1.0 | Reference | 234 | 1.0 | Reference | 249 | 1.0 | Reference |
| Past | ||||||||||||
| < 2 | 1,068 | 0.94 | 0.87 to 1.02 | 590 | 0.92 | 0.83 to 1.03 | 134 | 0.90 | 0.72 to 1.12 | 153 | 0.88 | 0.71 to 1.08 |
| 2 to 3 | 47 | 0.87 | 0.65 to 1.16 | 26 | 0.86 | 0.58 to 1.28 | 6 | 0.84 | 0.37 to 1.90 | 6 | 0.76 | 0.34 to 1.72 |
| > 3 | 40 | 0.97 | 0.71 to 1.34 | 24 | 1.01 | 0.67 to 1.51 | 3 | 0.56 | 0.18 to 1.77 | 5 | 0.92 | 0.38 to 2.24 |
| Ptrend | .46 | .80 | .68 | .38 | ||||||||
| Current | ||||||||||||
| < 2 | 644 | 0.90 | 0.82 to 0.99 | 315 | 0.83 | 0.73 to 0.94 | 104 | 1.07 | 0.85 to 1.35 | 78 | 0.76 | 0.58 to 0.98 |
| 2 to 3 | 186 | 0.89 | 0.76 to 1.04 | 106 | 0.92 | 0.75 to 1.13 | 35 | 1.27 | 0.89 to 1.82 | 21 | 0.72 | 0.46 to 1.12 |
| 4 to 5 | 152 | 0.88 | 0.74 to 1.04 | 83 | 0.88 | 0.70 to 1.10 | 14 | 0.63 | 0.36 to 1.08 | 24 | 1.01 | 0.66 to 1.54 |
| > 5 | 128 | 0.87 | 0.72 to 1.04 | 69 | 0.83 | 0.64 to 1.06 | 14 | 0.74 | 0.43 to 1.27 | 18 | 0.84 | 0.51 to 1.36 |
| Ptrend | .54 | .95 | .11 | .86 | ||||||||
| Duration, years of use by status | ||||||||||||
| Nonuser | 1,680 | 1.0 | Reference | 924 | 1.0 | Reference | 234 | 1.0 | Reference | 249 | 1.0 | Reference |
| Past | ||||||||||||
| ≤ 5 | 829 | 0.93 | 0.85 to 1.02 | 466 | 0.93 | 0.83 to 1.04 | 105 | 0.89 | 0.70 to 1.13 | 118 | 0.85 | 0.68 to 1.07 |
| 6 to 10 | 337 | 0.94 | 0.84 to 1.07 | 178 | 0.89 | 0.75 to 1.05 | 41 | 0.89 | 0.63 to 1.25 | 55 | 1.03 | 0.76 to 1.40 |
| > 10 | 49 | 0.80 | 0.59 to 1.06 | 29 | 0.94 | 0.64 to 1.37 | 7 | 0.99 | 0.46 to 2.15 | 2 | 0.24 | 0.06 to 0.99 |
| Ptrend | .75 | .94 | .28 | .33 | ||||||||
| Current | ||||||||||||
| ≤ 5 | 570 | 0.92 | 0.83 to 1.02 | 270 | 0.83 | 0.72 to 0.96 | 94 | 1.11 | 0.87 to 1.43 | 74 | 0.83 | 0.63 to 1.09 |
| 6 to 10 | 403 | 0.85 | 0.76 to 0.96 | 248 | 0.91 | 0.79 to 1.05 | 50 | 0.82 | 0.60 to 1.13 | 61 | 0.86 | 0.64 to 1.14 |
| > 10 | 226 | 0.90 | 0.78 to 1.04 | 105 | 0.78 | 0.63 to 0.96 | 35 | 1.12 | 0.77 to 1.63 | 22 | 0.66 | 0.42 to 1.04 |
| Ptrend | .16 | .28 | .15 | .44 | ||||||||
| Duration, years of use by dosage† | ||||||||||||
| Nonuser | 1,006 | 1.0 | Reference | 566 | 1.0 | Reference | 139 | 1.0 | Reference | 131 | 1.0 | Reference |
| Nonregular user (< two tablets per week)‡ | ||||||||||||
| ≤ 5 | 78 | 0.84 | 0.66 to 1.06 | 32 | 0.65 | 0.45 to 0.93 | 13 | 1.14 | 0.64 to 2.03 | 16 | 1.23 | 0.72 to 2.11 |
| 6 to 10 | 65 | 0.86 | 0.67 to 1.11 | 39 | 0.93 | 0.67 to 1.30 | 5 | 0.49 | 0.20 to 1.20 | 14 | 1.43 | 0.82 to 2.51 |
| > 10 | 59 | 0.88 | 0.68 to 1.15 | 24 | 0.68 | 0.45 to 1.03 | 8 | 0.95 | 0.46 to 1.96 | 5 | 0.61 | 0.25 to 1.50 |
| Ptrend | .53 | .45 | .68 | .76 | ||||||||
| Regular user (≥ two tablets per week)‡ | ||||||||||||
| ≤ 5 | 103 | 1.00 | 0.81 to 1.22 | 63 | 1.07 | 0.82 to 1.39 | 17 | 1.34 | 0.80 to 2.22 | 13 | 1.03 | 0.58 to 1.83 |
| 6 to 10 | 114 | 0.76 | 0.62 to 0.92 | 77 | 0.86 | 0.67 to 1.09 | 15 | 0.75 | 0.44 to 1.29 | 8 | 0.42 | 0.21 to 0.87 |
| > 10 | 224 | 0.87 | 0.75 to 1.01 | 113 | 0.81 | 0.65 to 0.99 | 28 | 0.85 | 0.56 to 1.30 | 28 | 0.90 | 0.59 to 1.37 |
| Ptrend | .89 | .36 | .19 | .22 | ||||||||
| Higher-dose user (≥ six tablets per week)‡ | ||||||||||||
| ≤ 10 | 104 | 0.87 | 0.71 to 1.06 | 69 | 0.95 | 0.74 to 1.23 | 17 | 1.05 | 0.63 to 1.76 | 7 | 0.46 | 0.21 to 0.99 |
| > 10 | 141 | 0.89 | 0.74 to 1.07 | 74 | 0.85 | 0.66 to 1.09 | 19 | 0.93 | 0.57 to 1.53 | 18 | 0.93 | 0.56 to 1.55 |
| Ptrend | .86 | .69 | .16 | .20 | ||||||||
Abbreviations: BMI, body mass index; ER, estrogen receptor; MET, metabolic equivalent of task; PR, progesterone receptor; RR, relative risk.
Multivariable RRs were adjusted for age (in months), age at menarche (≤ 12, 13, or ≥ 14 years), height (< 1.60, 1.60 to < 1.65, 1.65 to < 1.70, 1.70 to < 1.75, or ≥ 1.75 m), BMI at age 18 years (< 19, 19 to < 21, 21 to < 23, or ≥ 23 kg/m2 ), weight change since age 18 years (≤ −2, > −2 to < 2, 2 to < 10, 10 to < 20, or ≥ 20 kg), parity and age at first birth (nulliparous; one to two children, < 25 years; one to two children, ≥ 25 years; ≥ three children, < 25; ≥ three children, ≥ 25 years), history of breast cancer in parent or sibling (yes or no), history of benign breast disease (yes or no), alcohol consumption (0, > 0 to < 5, 5 to < 15, or ≥ 15 g per day), physical activity (< 3, 3 to < 27, or ≥ 27 MET-hours per week), and postmenopausal hormone use (never; past; current user, < 5 years; or current user, ≥ 5 years).
No. of nonusers was less, because the information on dosage (tablets per week) was not measured until 1998.
Regular aspirin user was defined as consumption of ≥ two standard 325-mg tablets per week. Nonregular user was defined otherwise.