Table 1.

Characteristics of breast cancer cases diagnosed from 1997 to 2007 at KPNC and matched controls by disease and HR status

CharacteristicAll controls, n = 224,860All cases, n = 22,488HR-negative cases, n = 3,996HR-positive cases, n = 18,492
Age at diagnosis/index date, mean year ± SD61.11 ± 13.3261.11 ± 13.3257.68 ± 13.4661.85 ± 13.17
Years of coverage, mean ± SD7.28 ± 3.197.28 ± 3.197.20 ± 3.157.30 ± 3.19
Oral contraceptive use, n (%)*19,080 (8.5)2,220 (9.9)468 (11.7)1,752 (9.5)
Menopausal hormone therapy use, n (%)89,664 (39.9)9,593 (42.7)1,553 (38.9)8,040 (43.5)
Lipophilic statin use, n (%)
    Never use169,816 (75.5)17,079 (76.0)3,160 (79.1)13,919 (75.3)
    Ever use55,044 (24.5)5,409 (24.0)836 (20.9)4,573 (24.7)
    ≥2-y use18,614 (8.3)1,888 (8.4)260 (6.5)1,628 (8.8)
Years of lipophilic statin use, mean ± SD
    Among ever users0.53 ± 1.380.54 ± 1.410.44 ± 1.220.56 ± 1.45
    Among ≥2-y users4.47 ± 2.204.55 ± 2.284.34 ± 2.274.58 ± 2.28
Race, n (%)
    Non-Hispanic Whiten/a16,256 (72.3)2,485 (62.2)13,771 (74.5)
    Hispanic Whiten/a1,574 (7.0)360 (9.0)1,214 (6.6)
    African Americann/a1,803 (8.0)590 (14.8)1,213 (6.6)
    Asian/Pacific Islandern/a2,410 (10.7)463 (11.6)1,947 (10.5)
    Othern/a455 (2.0)98 (2.5)347 (1.9)
  • *Oral contraceptive ever use within 10 years before diagnosis/index date.

  • Hormone therapy ever use within 5 years before diagnosis/index date.

  • Race information was captured by the KPNCCR and was available for cases only.