Table 1.

Background characteristics and ORs of breast cancer associated with lifestyle, reproductive, and socioeconomic factors among cases and controls from the MDC cohort

No. cases/controlsMeans in
P*
CasesControls
Age544/1,08857.157.10.99
Screening week of blood sample544/1,0881441440.98
Total crude mean daily intake
    Folate (μg/d)544/1,0882832790.53
    B12 (μg/d)544/1,08811.115.40.34
    B6 (mg/d)544/1,0883.15.80.28
    Riboflavin (mg/d)544/1,0882.62.60.33
    Fiber (g/d)544/1,08819.419.40.77
    β-Carotene (mg/d)544/1,0884.04.00.92
    Ascorbic acid (mg/d)544/1,0881811830.80
Anthropometry
    Weight544/1,08869.268.60.36
    Height544/1,088164.5163.60.005
    Body mass index544/1,08825.625.70.82

No. cases/controls
OR (95% CI)
P for trend
MHT
    No337/7961.00
    Yes165/2081.88 (1.47-2.39)
Contraceptive pill use, duration category (y)0.27
    0265/5401.00
    1-595/2050.95 (0.70-1.28)
    5-15103/2101.00 (0.75-1.34)
    >1573/1091.37 (0.97-1.94)
Parity category0.07
    No children64/961.00
    1 child111/2370.70 (0.48-1.04)
    2 children234/4690.75 (0.52-1.07)
    3 children94/1800.78 (0.52-1.17)
    4 or more26/840.46 (0.27-0.80)
Age at menopause category (y)0.81
    <4554/1161.00
    45-50138/2701.10 (0.75-1.60)
    50-55169/3541.02 (0.70-1.48)
    >5532/601.12 (0.65-1.94)
    Unknown§151/2881.17 (0.77-1.78)
Household work (h/wk)0.006
    0-9103/1661.00
    10-19206/3970.83 (0.61-1.12)
    20-29163/3270.80 (0.58-1.09)
    ≥3062/1760.56 (0.38-0.82)
Leisure-time physical activity0.74
    Low180/3601.00
    Medium188/3601.04 (0.82-1.34)
    High172/3590.96 (0.74-1.24)
Socioeconomic status<0.001
    Blue collar workers179/4271.00
    White collar workers, low168/3411.18 (0.91-1.52)
    White collar workers, medium104/1621.55 (1.14-2.10)
    White collar workers, high47/601.89 (1.24-2.88)
    Self-employed§37/871.02 (0.67-1.56)
Education (y)0.05
    >8199/4381.00
    9-10175/3491.12 (0.87-1.43)
    11-1369/1401.11 (0.79-1.56)
    University degree98/1571.41 (1.03-1.93)
Alcohol category0.07
    Zero consumption (g/d)37/921.00
    <15412/8231.25 (0.84-1.86)
    15-3075/1511.24 (0.77-2.00)
    >3020/202.50 (1.20-5.20)
Smoking0.34
    Never227/4921.00
    Ex166/2981.21 (0.94-1.55)
    Current151/2961.11 (0.86-1.43)
  • * ANOVA.

  • Adjusted for energy.

  • ORs were calculated with unconditional logistic regression. Adjusted for matching variables (age and blood sampling date).

  • § Not included in the trend analysis.

  • The P value does not strictly indicate a trend.