Table 3.

Serum sex hormone concentrations and other risk factors for ER+ breast cancer in the nested case-cohort study

FactorAge-adjusted
Adjusted*
Relative risk (95% CI)PRelative risk (95% CI)P
Weight (per 10 kg)1.2 (1.1-1.3)0.0021.1 (0.9-1.4)0.26
Education (>16 y)1.5 (1.0-2.2)0.052.1 (1.1-4.2)0.03
Distal radius BMD1.2(1.1-1.4)0.0031.2 (0.9-1.5)0.20
Testosterone
    Quintile 1 (reference)1.01.0
    Quintile 22.6 (1.2-5.4)0.012.4 (1.1-5.5)0.03
    Quintile 32.1 (1.0-4.4)0.062.2 (0.9-5.0)0.07
    Quintile 43.8 (1.9-7.8)4.0014.0 (1.8-8.6)<0.001
    Quintile 55.1 (2.5-10.3)<0.0013.8 (1.7-8.4)0.001
Estradiol§
    Quintile 1 (reference)1.01.0
    Quintile 20.8 (0.4-1.8)0.630.7 (0.3-1.7)0.44
    Quintile 31.4 (0.8-2.5)0.301.2 (0.6-2.2)0.66
    Quintile 41.8 (0.9-3.5)0.081.3 (0.6-2.8)0.45
    Quintile 52.9 (1.6-5.1)<0.0011.8 (0.9-3.6)0.11
  • Abbreviation: BMD, bone mineral density.

  • * Adjusted for weight, education, radius BMD, testosterone, and estradiol. Ptrend for estradiol = 0.06 and Ptrend for testosterone < 0.001.

  • Per SD increase.

  • Quintiles for testosterone (pmol/L): 1st, <381; 2nd, 381-553; 3rd, 554-727; 4th, 728-1074; 5th, >1,074.

  • § Quintiles for estradiol (pmol/L): 1st, <14; 2nd, 14-17; 3rd, 18-24; 4th, 25-32; 5th, >32.