Table 3.
Adjusted hazard ratios (and 95% CIs) for associations of incident breast cancer with baseline levels of CRP and PAI-1 with stratification by HT use
| Factor, model | Quartile 1 | Quartile 2 | Quartile 3 | Quartile 4 | P trend |
|---|---|---|---|---|---|
| Non-HT users at baseline | |||||
| CRP | |||||
| Quartile cutpoints, µg/mL | ≤0.91 | 0.92–2.01 | 2.02–4.57 | ≥4.58 | |
| No. case patients/No. subcohort members | 113/149 | 97/122 | 110/84 | 81/79 | |
| Age and ethnicity adjusted HR (95% CI) | 1.00 (referent) | 1.02 (0.71 to 1.48) | 1.82 (1.23 to 2.68) | 1.40 (0.93 to 2.10) | .010 |
| Multivariable-adjusted HR* (95% CI) | 1.00 (referent) | 1.00 (0.65 to 1.56) | 2.28 (1.36 to 3.81) | 1.63 (0.95 to 2.80) | .010 |
| PAI-1 | |||||
| Quartile cutpoints, pg/mL | ≤9187 | 9188-14 395 | 14 396–21 348 | ≥21 349 | |
| No. case subjects/No. subcohort members | 55/79 | 96/102 | 114/125 | 138/129 | |
| Age and ethnicity adjusted HR (95% CI) | 1.00 (referent) | 1.38 (0.88 to 2.15) | 1.35 (0.88 to 2.09) | 1.62 (1.06 to 2.48) | .045 |
| Multivariable-adjusted HR* (95% CI) | 1.00 (referent) | 1.47 (0.88 to 2.46) | 1.49 (0.89 to 2.52) | 1.71 (1.02 to 2.89) | .077 |
| HT users at baseline | |||||
| CRP | |||||
| Quartile cutpoints, µg/mL | ≤0.91 | 0.92–2.01 | 2.02–4.57 | ≥4.58 | |
| No. case patients/No. subcohort members | 86/59 | 98/85 | 128/111 | 142/108 | |
| Age- and ethnicity-adjusted HR (95% CI) | 1.00 (referent) | 0.82 (0.52 to 1.28) | 0.80 (0.52 to 1.22) | 0.94 (0.62 to 1.45) | .918 |
| Multivariable-adjusted HR* (95% CI) | 1.00 (referent) | 0.96 (0.56 to 1.66) | 0.75 (0.45 to 1.24) | 0.90 (0.53 to 1.53) | .509 |
| PAI-1 | |||||
| Quartile cutpoints, pg/mL | ≤9187 | 9188-14 395 | 14 396–21 348 | ≥21 349 | |
| No. case patients/No. subcohort members | 152/131 | 135/101 | 98/73 | 70/58 | |
| Age- and ethnicity-adjusted HR (95% CI) | 1.00 (referent) | 1.26 (0.87 to 1.81) | 1.18 (0.80 to 1.75) | 1.04 (0.68 to 1.59) | .706 |
| Multivariable-adjusted HR* (95% CI) | 1.00 (referent) | 1.31 (0.86 to 1.97) | 1.06 (0.65 to 1.72) | 1.17 (0.71 to 1.93) | .663 |
* Multivariable model adjusted for age, ethnicity, alcohol consumption, family history of breast cancer, parity, years of menstrual cycling, age at first child’s birth, type of hormone therapy (HT; in HT users only), endogenous estradiol levels (in non-HT users only), history of benign breast disease, body mass index, and physical activity. All statistical tests were two-sided. CI = confidence interval; CRP = C-reactive protein; HR = hazard ratio; HT = hormone therapy; PAI-1 = plasminogen activator inhibitor–1.