Table 1

Comparison of cases and controls by selected demographic factors and major risk factors for breast cancer from the Shanghai Breast Cancer Study, 1996–1998

Subjects included in whole studySubjects with genotying dataP
Cases (n = 1459) (1)Controls (n = 1556) (2)Cases (n = 1069) (3)Controls (n = 1166) (4)Case (3 versus 1)Control (4 versus 2)Case versus control (3 versus 4)
Demographic factors
 Age (yr)a47 (42, 53)46 (40, 54)47 (42, 53)46 (40, 54)0.0880.6660.230
 Education ≥ high school, %45.244.343.742.70.3460.2740.642
Major risk factor
 First-degree relative with breast cancer, %3.72.43.32.30.5100.8530.168
 Ever diagnosed with breast fibroadenoma, %9.65.09.95.20.7590.783<0.001
 Smoking, %2.62.52.42.70.7970.8110.734
 Drinking, %4.04.13.44.00.2980.9210.464
 Hormone replacement therapy, %2.92.72.72.50.7880.7210.838
 No regular leisure physical activity, %81.374.880.974.40.7820.758<0.001
 WHRa0.81 (0.77, 0.84)0.80 (0.76, 0.84)0.81 (0.77, 0.84)0.80 (0.76, 0.83)0.2090.495<0.001
  WHR >0.84, %26.721.326.320.60.7690.5540.001
 BMIa23.2 (21.2, 25.5)22.8 (20.7, 25.1)23.1 (21.2, 25.6)22.9 (20.8, 25.2)0.8920.2960.035
  ≥25, %30.425.831.026.90.6940.4120.036
 Age at menarche (yr)a14 (13, 16)15 (13, 16)14 (13, 16)15 (13, 16)0.6500.5960.001
  Age at menarche ≤13 yr, %31.626.531.625.90.9810.6370.003
 Premenopausal, %65.563.867.264.10.2630.8240.130
  Age at menopause ≥50 yrb, %40.537.241.037.20.9060.9660.282
 No live birth, %5.13.94.94.10.8110.7870.393
  Age at first live birth ≥30 yra, %22.216.522.016.30.9000.906<0.001
 Calorie intake (Kcal)a1796 (1541, 2128)1782 (1529, 2075)1795 (1536, 2132)1784 (1535, 2087)0.9940.6780.278
 Fat (g)a32.9 (25.0, 43.5)32.5 (24.6, 43.2)33.1 (24.9, 44.0)32.5 (24.5, 43.0)0.7870.9580.088
 Protein (g)a73.5 (60.2, 91.0)71.9 (59.5, 87.1)73.3 (60.2, 91.0)71.8 (59.1, 87.0)0.7370.9690.013
 Carbohydrate (g)a313.0 (272.7, 366.1)310.2 (269.8, 360.0)313.9 (272.8, 366.5)312.9 (270.3, 361.5)0.9990.5340.852
  • a Median (25th, 75th percentile) are presented, P were derived from test.

  • b Among postmenopausal women.

  • c Among parous women.