Table 7

ORs for breast cancer associated with serum levels of PCBs by congener group

Serum level (ppb)Cases (n = 475)aControls (n = 502)aORb (95% CI)ORc (95% CI)
Group 1: Potentially estrogenic
<52.6951141.001.00
52.6–61.51041151.16 (0.79–1.70)1.14 (0.77–1.70)
61.6–78.91601441.42 (0.99–2.02)1.45 (0.99–2.11)
≥79.01161291.26 (0.85–1.85)1.32 (0.87–2.01)
P for trend0.660.71
Group 2: Potentially antiestrogenic
<247.01121291.001.00
247.0–292.91171151.21 (0.84–1.73)1.22 (0.84–1.77)
293.0–379.91441311.33 (0.94–1.89)1.35 (0.94–1.93)
≥380.01021270.96 (0.67–1.39)0.96 (0.65–1.40)
P for trend0.950.95
Group 3: Phenobarbital, CYP1A, and CYP2B inducers
<212.01271241.001.00
212.0–256.51151290.88 (0.62–1.26)0.87 (0.60–1.25)
256.6–332.9981240.78 (0.54–1.12)0.78 (0.54–1.15)
≥333.01351251.03 (0.72–1.46)1.02 (0.71–1.47)
P for trend0.890.85
  • 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.