Angiotensin Receptor Blockers Associated with Improved Breast Cancer Survival-A Nationwide Cohort Study from Finland.

BACKGROUND

Breast cancer incidence has been associated with hypertension, which might worsen disease prognosis, but few nationwide studies have investigated the association between antihypertensive drug use and breast cancer prognosis.

METHODS

A cohort of 73,170 women diagnosed with breast cancer during 1995-2013 identified from the Finnish Cancer Registry was combined with information on antihypertensive drug use during the same time period from a national prescription database. Antihypertensive drugs were analyzed in groups categorized by mechanism of action. Usage of antihypertensive drugs, statins, antidiabetic, and anticoagulative drugs was analyzed as time-dependent exposure to model for simultaneous use of multiple drug groups. Influence of protopathic bias was evaluated in lag-time analyses.

RESULTS

In prediagnostic use, only angiotensin receptor (ATR)-blockers were associated with decreased risk of breast cancer death as compared with nonusers (HR: 0.76, 95% confidence interval, CI: 0.69-0.82), and there was an inverse association with cumulative dose of use. Postdiagnostic use of ATR-blockers, angiotensin-converting enzyme (ACE)-inhibitors, beta-blockers, and calcium-channel blockers was dose dependently associated with better breast cancer survival compared with nonusers. The risk decrease was strongest for ATR-blockers (HR: 0.69, 95% CI: 0.63-0.75) and remained for exposures occurring up to 3 years earlier.

CONCLUSIONS

Only ATR-blockers were associated with improved breast cancer survival in both prediagnostic and postdiagnostic use. The association was dose dependent and supported by a biological rationale as a causal explanation. In postdiagnostic use, similar reduction was found also for other antihypertensives, supporting a prognostic role of hypertension control.

IMPACT: Inhibition of angiotensin receptor subtype 1 (AT1) could be a promising novel way to affect breast cancer progression.