Long-term use of calcium channel blocking drugs and breast cancer risk in a prospective cohort of US and Puerto Rican women

Table 4 Hazard ratios of incident breast cancer by strata of calcium channel blocker use in long-term antihypertensive users

Calcium channel blockers	Limited to women currently using an antihypertensive drug for 5 years or more (N = 8057)	Limited to women currently using an antihypertensive drug for 10 years or more (N = 3879)
Never used	Reference	Reference
Former user	0.87 (0.36–2.11)	0.80 (0.20–3.24)
Current user (<5 years)	1.06 (0.71–1.58)	1.09 (0.60–1.99)
(5–10 years)	1.14 (0.81–1.61)	1.15 (0.58–2.29)
(10+ years)	0.89 (0.58–1.36)	0.89 (0.57–1.40)

Data presented as breast cancer hazard ratio (95 % confidence interval)
Hazard ratios of incident breast cancer by strata of calcium channel blocker use in long-term antihypertensive users when the analytic population is limited to women who have been using an antihypertensive drug for at least 5 years (N = 8058) or at least 10 years (N = 3879) at baseline. Hazard ratios were calculated using Cox proportional hazards regression with age as the time scale and adjusted for race/ethnicity, categorized body mass index, parity, age at menarche, menopause status, statin use, smoking status, hormone therapy use, and reported hours of physical activity per week

ISSN: 1465-542X