Table 4

Adjusteda risks by quartiles of biochemical activityb of major galactose enzymes, alone and relative to estimated lactose consumption

Variable/quartileCasesControlsOR(95% CI)P for trend
n(%)n(%)
Transferase
4th158(31.0)106(24.8)1.0
3rd122(24.2)112(26.2)0.70(0.49–1.01)
2nd89(17.5)99(23.1)0.60(0.41–0.88)
1st139(27.4)111(25.9)0.82(0.57–1.17)0.65
Kinase
4th120(26.4)97(25.3)1.0
3rd131(26.9)89(23.2)1.19(0.81–1.76)
2nd120(24.6)100(26.1)0.97(0.66–1.42)
1st116(23.8)97(25.3)1.01(0.68–1.49)0.68
Epimerase
4th96(19.7)91(23.9)1.0
3rd105(21.6)101(26.5)1.00(0.67–1.50)
2nd142(29.2)93(24.4)1.54(1.03–2.30)
1st144(29.6)96(25.2)1.52(1.02–2.28)0.002
L:Tc
1st125(24.9)104(24.4)1.0
2nd143(28.5)112(26.3)1.12(0.77–1.62)
3rd115(22.9)104(24.4)0.90(0.62–1.31)
4th119(23.7)106(24.9)0.93(0.64–1.36)0.379
L:Kd
1st115(23.9)96(25.2)1.0
2nd137(28.5)94(24.7)1.25(0.85–1.84)
3rd112(23.3)96(25.2)1.01(0.68–1.50)
4th117(24.3)95(24.9)1.04(0.70–1.54)0.17
L:Ee
1st127(26.4)93(24.5)1.0
2nd95(19.8)96(25.3)0.66(0.45–0.99)
3rd108(22.4)95(25.1)0.80(0.54–1.19)
4th151(31.4)95(25.1)1.12(0.77–1.64)0.17
  • a Adjusted for age (continuous), BMI (continuous), parity (0, ≥1), OC use (<3 mon, ≥3 mon), first-degree relative with breast or ovarian cancer, site (MA, NH), and education (≤12 yr, >12 yr).

  • b Units of activity are micromoles of hexose conversion/h/g hemoglobin.

  • c L:T, ln (lactose) × 10:transferase (ratio of lactose consumption to transferase enzyme activity).

  • d L:K, ln (lactose) × kinase (ratio of lactose consumption to kinase enzyme activity).

  • e L:E, ln (lactose) × 10:epimerase (ratio of lactose consumption to epimerase enzyme activity).