Use of antihypertensive medications and breast cancer risk among women aged 55 to 74 years.
OBJECTIVE
Antihypertensive agents are the most commonly prescribed class of medications in the United States. Evidence regarding the relationship between different types of antihypertensives and breast cancer risk is sparse and inconsistent, and prior studies have lacked the capacity to assess impacts of long-term use.


OBJECTIVE
To evaluate associations between use of various classes of antihypertensive medications and risks of invasive ductal and invasive lobular breast cancers among postmenopausal women.


METHODS
Population-based case-control study in the 3-county Seattle-Puget Sound metropolitan area. Participants were women aged 55 to 74 years, 880 of them with invasive ductal breast cancer, 1027 with invasive lobular breast cancer, and 856 with no cancer serving as controls.


METHODS
Recency and duration of use of antihypertensive medications.


METHODS
Risks of invasive ductal and invasive lobular breast cancers.


RESULTS
Current use of calcium-channel blockers for 10 or more years was associated with higher risks of ductal breast cancer (odds ratio [OR], 2.4; 95% CI, 1.2-4.9) (P= .04 for trend) and lobular breast cancer (OR, 2.6; 95% CI, 1.3-5.3) (P= .01 for trend). This relationship did not vary appreciably by type of calcium-channel blocker used (short-acting vs long-acting, dihydropyridines vs non-dihydropyridines). In contrast, use of diuretics, β-blockers, and angiotensin II antagonists were not associated with risk.


CONCLUSIONS
While some studies have suggested a positive association between calcium-channel blocker use and breast cancer risk, this is the first study to observe that long-term current use of calcium-channel blockers in particular are associated with breast cancer risk. Additional research is needed to confirm this finding and to evaluate potential underlying biological mechanisms.
Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington.
Christopher I
CI
Li
Janet R
JR
Daling
Mei-Tzu C
MT
Tang
Kara L
KL
Haugen
Peggy L
PL
Porter
Kathleen E
KE
Malone
D000368:Aged; D000959:Antihypertensive Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology; D018270:Carcinoma, Ductal, Breast / Q000453:epidemiology* / Q000209:etiology; D018275:Carcinoma, Lobular / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000188:drug therapy*; D015994:Incidence; D008875:Middle Aged; D016017:Odds Ratio; D017698:Postmenopause; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D014861:Washington / Q000453:epidemiology
D000959:Antihypertensive Agents