Table 1.

Breast cancer risk by plasma folate levels and XRCC1 Arg194Trp

1 (Lowest)234 (Highest)P for trend
194Trp non-carriers
Cases/Controlsa182/156164/150155/148136/144
Multivariate ORb1.000.92 (0.67–1.26)0.89 (0.65–1.21)0.80 (0.58–1.10)0.18
Multivariate ORc1.000.98 (0.71–1.35)0.85 (0.61–1.17)0.77 (0.55–1.07)0.09
194Trp carriers
Cases/Controlsa25/2322/2215/2312/28
Multivariate ORb0.94 (0.51–1.73)0.86 (0.46–1.62)0.55 (0.28–1.09)0.37 (0.18–0.75)0.02
Multivariate ORc0.87 (0.46–1.64)0.88 (0.46–1.70)0.50 (0.25–1.02)0.34 (0.16–0.72)0.01
  • P, interaction = 0.12 in the multivariate model C

  • 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 (continuous), weight gain since age 18 (<5 kg, 5–19.9, ≥20), age at menarche (<12 years, 12, 13, >13), 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, 3+ children/age at first birth ≤24, 3+ children/age at first birth >24), 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), and postmenopausal hormone use (never use, past use, current use <5years, current use ≥5years).