Table 3.

Association between statin use and breast cancer risk

Statin use	Breast cancer cases	Disease free	Age-adjusted HR (95% CI)	Multivariable-adjusted HR (95% CI)*
All women	n=2,707 %	n=90,081 %
Never	95.2	92.6	referent	referent
Ever	4.8	7.4	1.15 (0.96–1.38)	1.07 (0.88–1.29)
Current	4.5	6.7	1.17 (0.97–1.41)	1.08 (0.89–1.31)
Hydrophobic only**	3.1	6.3	1.09 (0.88–1.36)	1.01 (0.80–1.26)
Hydrophilic only***	0.3	0.1	1.05 (0.50–2.21)	1.01 (0.48–2.13)
Duration of use among women with 5+ years of data†	n=1,682 %	n= 57,666 %
Never	93.4	89.9	referent	referent
All statins
1–2.9 yrs	2.7	4.4	0.96 (0.71–1.29)	0.96 (0.71–1.31)
3–4.9 yrs	1.8	2.4	1.09 (0.76–1.55)	1.04 (0.72–1.51)
5+ yrs	2.1	3.3	1.28 (0.91–1.79)	1.27 (0.89–1.81)
Hydrophobic statins only**
1–2.9 yrs	2.7	4.5	0.90 (0.64–1.26)	0.90 (0.64–1.26)
3–4.9 yrs	1.5	2.2	1.19 (0.79–1.79)	1.12 (0.74–1.71)
5+ yrs	1.0	2.2	1.51 (0.92–2.49)	1.47 (0.89–2.44)

HR=hazard ratio and CI=confidence interval

^*Multivariable-adjusted models include age, hormone therapy use (HT), diabetes, other lipid lowering drug use, and BMI

^**Includes users of lovastatin, simvastatin, fluvastatin, atorvastatin, and cerivastatin

^***Includes users of pravastatin and rosuvastatin

^†p=0.3 from linear trend test for the effect of the duration of statin use and duration of hydrophobic statin use on breast cancer risk