Table 1.

Selected characteristics for 989 breast cancer cases and 1,054 control subjects (adjusted OR)

Case (%), n = 989Control (%)
OR (95% CI)*, P*
Hospital
Community
All
n = 583n = 471n = 1,054
Age (mean ± SD)47.0 ± 10.147.5 ± 13.451.2 ± 9.949.2 ± 12.1<0.001
Education
Under high school312 (31.6)233 (40.2)172 (37.2)405 (38.9)1.0 (reference)
At/over high school674 (68.4)347 (59.8)290 (62.8)637 (61.1)1.1 (0.85-1.31)
Fx of BrCa
No922 (93.2)568 (97.4)456 (96.8)1024 (97.2)1.0 (reference)
Yes67 (6.8)15 (2.6)15 (3.2)30 (2.9)2.5 (1.60-4.02)
LEE (per 5 y)29.0 ± 6.227.0 ± 7.631.1 ± 6.128.8 ± 7.31.3 (1.18-1.45)
Oral contraceptive use
No840 (85.0)468 (88.0)402 (85.7)870 (86.9)1.0 (reference)
Yes148 (15.0)64 (12.0)67 (14.3)131 (13.1)1.2 (0.95-1.59)
HRT
No769 (88.6)372 (95.9)438 (93.0)810 (94.3)1.0 (reference)
Yes99 (11.4)16 (4.1)33 (7.0)49 (5.7)2.5 (1.73-3.64)
Alcohol consumption
<1/mo746 (75.4)417 (71.5)341 (78.9)758 (74.7)1.0 (reference)
≤1-3/mo161 (16.3)131 (22.5)49 (11.3)180 (17.7)0.8 (0.64-1.05)
≥1/wk82 (8.3)35 (6.0)42 (9.7)77 (7.6)1.0 (0.71-1.39)
Cigarette smoking
<400 cigarettes/lifetime894 (90.5)536 (91.9)445 (94.7)981 (93.2)1.0 (reference)
≥400 cigarettes/lifetime94 (9.5)47 (8.1)25 (5.3)72 (6.8)1.5 (1.05-2.05)
  • NOTE: Abbreviation: LEE, lifetime estrogen exposure.

  • * OR of case versus all control adjusted for age, family history of breast cancer, and lifetime estrogen exposure.

  • P < 0.05 by χ2 test or Student's t test between hospital-based control and community control.

  • Fx of BrCa, family history of breast cancer in first- and second-degree relatives.