Table 6

Risk of breast cancer associated with lipid-adjusted serum levels of PCBs

Serum level (ppb)Cases (n = 475)aControls (n = 502)aORb (95% CI)ORc (95% CI)
All subjects
<604.01551641.001.00
604.0–800.01601671.02 (0.75–1.39)1.04 (0.76–1.45)
>800.01601710.96 (0.70–1.31)0.95 (0.68–1.32)
P for trend0.440.41
Parous women who ever breast fed
<604.061661.001.00
604.0–800.061750.89 (0.55–1.45)0.94 (0.56–1.58)
>800.052640.86 (0.52–1.43)0.97 (0.56–1.68)
P for trend0.400.89
Parous women who never breast fedd
<604.076711.001.00
604.0–800.076671.06 (0.66–1.70)1.01 (0.62–1.66)
>800.087801.00 (0.63–1.57)0.94 (0.58–1.55)
P for trend0.680.65
Nulliparous womene
<604.017261.001.00
604.0–800.023251.31 (0.57–3.00)1.52 (0.56–4.16)
>800.020271.06 (0.45–2.49)0.77 (0.27–2.21)
P for trend0.660.80
  • a Total number of cases or controls.

  • b Adjusted only for age (<47, 47–52, 53–63,≥ 64 years).

  • c Additional adjustments include BMI (<21, 21–24.9, ≥25 kg/m2), age at menarche (<13, 13–14, ≥15 years), lifetime months of lactation (0, 1–10, ≥11), age at first full-term pregnancy (nulliparous, <20, 20–25, ≥26 years), number of live births (0, 1–3, ≥4), lifetime months of hormone replacement therapy (0, 1–71, ≥72), dietary fat intake in g/day (<46, 46–71,≥ 72, unknown), family breast cancer history, income (<$20,000, $20,000–24,999, ≥$25,000, or unknown), race (white, black, and other), and study site.

  • d Not adjusted for lactation.

  • e Not adjusted for lactation, age at first full-term pregnancy, and number of live births.