Table 1.
Association between breast cancer risk and non-genetic risk factors by Indigenous American ancestry in Hispanics from the Breast Cancer Health Disparities Study
| Low Indigenous American ancestry (N=557) |
Interm. Indigenous American ancestry (N=3098) |
High Indigenous American ancestry (N=1078) |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Category | OR | 95%CI | P | OR | 95%CI | P | OR | 95%CI | P | |
| Age at dx/interview (Ref: ≤40) | 41–50 | 1.39 | 0.78–2.48 | 0.258 | 1.47 | 1.15–1.85 | 0.001 | 1.13 | 0.77–1.63 | 0.524 |
| 51–60 | 1.11 | 0.62–1.98 | 0.715 | 1.38 | 1.08–1.75 | 0.009 | 1.03 | 0.69–1.51 | 0.886 | |
| >60 | 1.36 | 0.75–2.43 | 0.301 | 1.36 | 1.06–1.74 | 0.014 | 1.10 | 0.72–1.66 | 0.661 | |
| Family history BC (Ref: No) | Yes | 1.71 | 1.07–2.73 | 0.023 | 1.37 | 1.08–1.72 | 0.008 | 2.63 | 1.38–4.98 | 0.003 |
| Anthropometrics | ||||||||||
| BMI (kg/m2) (Ref: <25) | 25–29 | 0.83 | 0.54–1.28 | 0.406 | 0.74 | 0.60–0.90 | 0.004 | 0.74 | 0.51–1.06 | 0.104 |
| ≥30 | 0.81 | 0.53–1.22 | 0.318 | 0.62 | 0.51–0.75 | <0.001 | 0.69 | 0.47–0.98 | 0.041 | |
| W-H ratio (Ref: Below the mean) | Above the mean | 1.09 | 0.73–1.61 | 0.672 | 1.07 | 0.91–1.24 | 0.378 | 0.79 | 0.59–1.06 | 0.122 |
| Height (Ref: Below the mean) | Above the mean | 1.03 | 0.70–1.51 | 0.873 | 1.19 | 1.02–1.37 | 0.02 | 1.43 | 1.07–1.88 | 0.013 |
| Lifestyle | ||||||||||
| Smoking (Ref: Never) | Ever | 1.13 | 0.76–1.66 | 0.539 | 1.08 | 0.91–1.27 | 0.35 | 1.04 | 0.76–1.42 | 0.789 |
| Daily alcohol intake (Ref: None) | ≤10gms/day | 0.95 | 0.64–1.40 | 0.801 | 1.01 | 0.83–1.23 | 0.903 | 0.88 | 0.43–1.80 | 0.735 |
| >10gms/day | 1.49 | 0.88–2.51 | 0.137 | 1.41 | 1.02–1.94 | 0.034 | 0.37 | 0.03–3.54 | 0.392 | |
| Reproductive characteristics | ||||||||||
| Parity/AFFTP (Ref: nulliparous) | 1–2 children/<25 years of age | 1.09 | 0.58–2.03 | 0.794 | 0.69 | 0.50–0.93 | 0.018 | 0.56 | 0.33–0.95 | 0.033 |
| 1–2 children/≥25 years of age | 1.34 | 0.74–2.43 | 0.331 | 0.69 | 0.51–0.94 | 0.018 | 0.91 | 0.53–1.53 | 0.728 | |
| ≥3 children/<25 years of age | 0.97 | 0.54–1.69 | 0.903 | 0.43 | 0.32–0.56 | <0.001 | 0.57 | 0.36–0.89 | 0.016 | |
| ≥3 children/≥25 years of age | 1.32 | 0.63–2.70 | 0.457 | 0.54 | 0.38–0.75 | <0.001 | 0.60 | 0.32–1.08 | 0.091 | |
| Breastfeeding if parous (Ref: No) | ≤12 months | 0.85 | 0.54–1.30 | 0.453 | 0.86 | 0.71–1.03 | 0.108 | 0.75 | 0.51–1.11 | 0.156 |
| >12 months | 0.70 | 0.43–1.12 | 0.137 | 0.56 | 0.45–0.68 | <0.001 | 0.52 | 0.33–0.80 | 0.003 | |
| Oral contraceptive use (Ref: Never) | Ever | 1.13 | 0.78–1.62 | 0.512 | 1.05 | 0.90–1.20 | 0.544 | 1.12 | 0.87–1.43 | 0.376 |
| Age at menarche (Ref: ≤11 yrs.) | 12 to 13 | 1.20 | 0.80–1.80 | 0.370 | 0.85 | 0.70–1.01 | 0.078 | 1.04 | 0.75–1.44 | 0.798 |
| >13 | 0.83 | 0.51–1.32 | 0.434 | 0.80 | 0.66–0.97 | 0.03 | 0.80 | 0.55–1.13 | 0.209 | |
| Menopause (Ref: Premenopausal) | Postmenopausal | 0.97 | 0.67–1.38 | 0.853 | 1.01 | 0.87–1.17 | 0.857 | 0.91 | 0.70–1.16 | 0.438 |
| Postmenopausal women only | N=325 | N=1793 | N=591 | |||||||
| Age at menopause (Ref: age ≤50) | . ≥50 yrs. | 1.22 | 0.75–1.96 | 0.409 | 1.12 | 0.91–1.37 | 0.276 | 1.17 | 0.81–1.69 | 0.392 |
| BMI (Ref: <25) | 25–29 | 0.93 | 0.52–1.65 | 0.816 | 0.83 | 0.63–1.09 | 0.193 | 0.86 | 0.50–1.46 | 0.585 |
| ≥30 | 0.67 | 0.38–1.16 | 0.154 | 0.67 | 0.51–0.86 | 0.003 | 0.83 | 0.49–1.39 | 0.476 | |
| Hormone therapy use (Ref: Never)* | Former | 0.64 | 0.36–1.15 | 0.137 | 0.88 | 0.69–1.13 | 0.321 | 1.19 | 0.76–1.86 | 0.456 |
| Current | 2.03 | 1.18–3.47 | 0.01 | 1.71 | 1.33–2.19 | <0.001 | 5.90 | 2.13–16.33 | 0.001 | |
Abbreviations: Interm: Intermediate; dx: diagnosis; BC: breast cancer; BMI: body mass index; W-H ratio: Waist to hip ratio; AFFP: Age at first full-term pregnancy.
*
P value for interaction between ancestry category and reproductive/lifestyle variable = 0.05