Table 1.

Characteristics of breast cancer cases diagnosed during 1997 to 2007 at KPNC and matched controls, by disease and hormone receptor status

CharacteristicsAll controls N = 208,640All cases N = 20,864HR-negative cases N = 3,669HR-positive cases N = 17,195
Age at diagnosis/index date (y): mean ± SD61.88 ± 13.0061.76 ± 13.0058.59 ± 13.2462.65 ± 12.84
Years of prescription drug coverage: mean ± SD7.43 ± 3.187.43 ± 3.187.37 ± 3.157.44 ± 3.19
Oral contraceptive usea: n, (col%)13,492 (6.5)1,618 (7.7)335 (9.1)1,283 (7.5)
Menopausal hormone therapy useb: n, (col%)68,347 (32.8)7,673 (36.8)1,203 (32.8)6,470 (37.6)
Lipophilic statin use: n, (col%)
 Never use174,537 (83.6)17,464 (83.7)3,147 (85.8)14,317 (83.3)
 “Ever” use34,103 (16.3)3,000 (16.3)522 (14.2)2,878 (16.7)
 “≥2 years” use18,343 (8.8)1,850 (8.9)257 (7.0)1,593 (9.3)
Years of lipophilic statin use: mean ± SD
 Among “Ever” users0.91 ± 1.720.87 ± 1.720.75 ± 1.530.90 ± 1.76
 Among “≥2 years” users4.48 ± 2.214.55 ± 2.294.35 ± 2.274.59 ± 2.29
Race/ethnicityc: n, (col%)
 Non-Hispanic Whiten/a15,283 (73.2)2,322 (63.3)12,961 (75.4)
 Hispanic Whiten/a1,386 (6.6)318 (8.7)1,068 (6.2)
 African Americann/a1,597 (7.6)517 (14.1)1,080 (6.3)
 Asian/Pacific Islandern/a2,193 (10.5)419 (11.4)1,774 (10.3)
 Othern/a405 (1.9)93 (2.5)312 (1.8)
  • aOral contraceptive “ever” use within 10 years before diagnosis/index date.

  • bHormone therapy “ever” use within 5 years before diagnosis/index date.

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