Table 2.

Associations between statin use and risk of invasive ductal or lobular breast cancer among women age 50 to 74 overall and among women with a history of high cholesterol

All study participants
Controls (n = 877)Ductal cases (n = 891)Lobular cases (n = 1,036)
N (%)N (%)OR (95% CI)N (%)OR (95% CI)
Never use674 (77)664 (75)1.00 (reference)782 (76)1.00 (reference)
Ever use for ≥6 months190 (22)206 (23)1.16 (0.92–1.47)237 (23)1.22 (0.98–1.53)
Duration of ever use
 6 months–<5 years104 (12)93 (11)0.93 (0.68–1.26)122 (12)1.12 (0.84–1.49)
 5 yrs–<10 yrs50 (6)57 (6)1.26 (0.84–1.89)51 (5)1.03 (0.68–1.56)
 ≥10 years35 (4)53 (6)1.72 (1.10–2.71)62 (6)1.82 (1.17–2.82)
PtrendP = 0.173P = 0.090
Recency of use
 Former use20 (2)20 (2)1.12 (0.59–2.13)19 (2)1.02 (0.53–1.95)
 Current use170 (19)184 (21)1.16 (0.91–1.15)218 (21)1.25 (0.98–1.57)
Duration of current use
 6 months–<5 years91 (10)79 (9)0.90 (0.65–1.24)109 (11)1.13 (0.83–1.53)
 5 yrs–<10 yrs47 (5)54 (6)1.26 (0.83–1.91)47 (5)1.00 (0.65–1.53)
 ≥10 yrs31 (4)50 (6)1.83 (1.14–2.93)60 (6)1.97 (1.25–3.12)
P-trendP = 0.043P = 0.021
Study participants with a history of high cholesterol
Controls (n = 273)Ductal cases (n = 286)Lobular cases (n = 320)
N (%)N (%)OR (95% CI)N (%)OR (95% CI)
 Never use85 (31)71 (25)1.00 (Ref)77 (24)1.00 (Ref)
 Ever use for ≥6 months175 (64)195 (68)1.42 (0.96–2.09)227 (71)1.64 (1.12–2.41)
 Current use158 (57.9)175 (61)1.41 (0.95–2.08)208 (65)1.63 (1.11–2.41)
Duration of ever use
 6 months–<5 yrs93 (34)88 (31)1.19 (0.77–1.84)116 (37)1.55 (1.01–2.37)
 5 yrs–<10 years48 (18)54 (19)1.46 (0.87–2.44)48 (15)1.31 (0.77–2.22)
 ≥10 years33 (12)51 (18)2.04 (1.17–3.57)61 (19)2.43 (1.40–4.21)
PtrendP = 0.025P = 0.006

NOTE: OR adjusted for reference year, reference age, county of residence, and HRT. Bold values signify statistically significant estimates (P value <0.05).