Table 3

Multivariate-adjusteda ORs and 95% CIs for HER-2/neu-positive (+) and HER-2/neu-negative (−) breast cancer among women <45 years of age in New Jersey, 1990–1992

HER-2/neu+ OR (95% CI)HER-2/neu− OR (95% CI)Ratio of the ORs (95% CI)
Age at first use of OCs (in years)
 Never users1.01.0
 <181.89 (0.97–3.85)0.97 (0.47–2.00)1.99 (0.87–4.54)
 18–211.09 (0.68–1.77)1.24 (0.82–1.87)0.88 (0.52–1.50)
 22+1.46 (0.88–2.42)0.84 (0.52–1.36)1.75 (0.98–3.12)
Body mass index
 <231.01.0
 23–260.80 (0.50–1.26)0.71 (0.46–1.08)1.13 (0.67–1.90)
 27+0.76 (0.47–1.23)0.80 (0.52–1.22)0.96 (0.56–1.62)
Age at first birth (for each additional year)1.02 (0.97–1.06)1.06 (1.02–1.10)0.96 (0.91–1.01)
Parous
 Ever1.01.0
 Never1.03 (0.63–1.68)1.27 (0.82–1.96)0.81 (0.47–1.40)
Age at menarche
 8–121.01.0
 13+0.73 (0.49–1.07)0.64 (0.45–0.91)1.14 (0.74–1.77)
Family history
 None1.01.0
 First degree2.13 (1.16–3.91)2.25 (1.29–3.91)0.95 (0.52–1.75)
Prior breast biopsy
 No1.01.0
 Yes2.08 (0.98–4.42)2.65 (1.36–5.17)0.78 (0.37–1.65)
Caloric intake (kilocalories, in quartiles)
 <11001.01.0
 1100–14501.44 (0.82–2.51)1.52 (0.92–2.51)0.95 (0.50–1.78)
 1450–18301.02 (0.56–1.85)1.32 (0.79–2.22)0.77 (0.39–1.51)
 ≥18302.04 (1.19–3.52)1.57 (0.95–2.64)1.29 (0.69–2.42)
  • a Adjusted for age and all other variables in the Table.