Table 4

Breast cancer risk by plasma carotene levels and XRCC1 Arg194Trp

1 (Lowest)234 (Highest)P for trend
Plasma α-carotene level
194Trp noncarriers
  Case/controlsa229/217233/214246/203173/210
  Multivariate OR1b1.001.03 (0.79–1.35)1.15 (0.89–1.50)0.78 (0.59–1.03)0.07
  Multivariate OR2c1.000.97 (0.74–1.28)1.12 (0.84–1.48)0.68 (0.50–0.92)0.008
194Trp carriers
  Case/controlsa30/2135/3021/3518/32
  Multivariate OR1b1.36 (0.76–2.46)1.12 (0.67–1.90)0.57 (0.32–1.01)0.53 (0.29–0.98)0.01
  Multivariate OR2c1.30 (0.70–2.40)1.19 (0.69–2.05)0.53 (0.30–0.97)0.40 (0.21–0.77)0.03
P = 0.03 by the nominal test for interaction and 0.02 by the ordinal test in the multivariate model 2.
Plasma β-carotene level
194Trp noncarriers
  Case/controlsa215/217244/215240/214182/198
  Multivariate OR1b1.001.14 (0.87–1.48)1.14 (0.87–1.48)0.93 (0.70–1.23)0.38
  Multivariate OR2c1.001.15 (0.87–1.52)1.11 (0.83–1.47)0.84 (0.62–1.14)0.07
194Trp carriers
  Case/controlsa32/2228/2829/2815/40
  Multivariate OR1b1.48 (0.83–2.64)1.03 (0.59–1.80)1.04 (0.60–1.81)0.37 (0.20–0.70)0.001
  Multivariate OR2c1.38 (0.76–2.51)1.13 (0.63–2.01)1.01 (0.57–1.81)0.32 (0.16–0.61)0.003
P = 0.02 by the nominal test for interaction and 0.003 by the ordinal test in the multivariate model 2.
  • a The number of participants does not sum to total women because of missing data on genotype.

  • b Unconditional logistic regression adjusted for the matching variables: age; menopausal status; postmenopausal hormone use; date of blood draw; time of blood draw; and fasting status.

  • c Unconditional logistic regression adjusted for the matching variables, BMI at age 18 years (continuous), weight gain since age 18 years (<5, 5–19.9, ≥20 kg), age at menarche (<12, 12, 13, >13 years), age at menopause (<45, ≥45 to <50, ≥50 to <55, or ≥55 years), parity/age at first birth (nulliparous, 1–2 children/age at first birth ≤24 years, 1–2 children/age at first birth >24 years, 3+ children/age at first birth ≤24 years, 3+ children/age at first birth >24 years), first-degree family history of breast cancer (yes/no), history of benign breast disease (yes/no), alcohol intake (0, >0 to <5, ≥5 to <15, ≥15 to <30, ≥30 g/day), during smoking (0, >0 to <20, ≥20 to <35, ≥35 years), and duration of postmenopausal hormone use (never use, past use, current use <5 years, current use ≥5 years).