Diuretics, beta-blockers may increase risk of adverse breast cancer outcomes
Exposure to diuretics and beta-blockers appears to carry some risk of adverse breast outcomes in older women, as shown in a study.
Drawing data from the Surveillance, Epidemiology and End-Results–Medicare database, the study included 14,766 women aged 66 to 80 years diagnosed with incident stage I/II breast cancer.
Time-varying Cox proportional hazard models were used to investigate outcomes—including a second breast cancer event (SBCE; a composite of a recurrence or a second contralateral primary breast cancer), breast cancer recurrence and breast cancer-specific mortality—in relation to the patients’ postcancer use of various antihypertensive medications.
Of the patients, 791 had SBCEs, 627 had breast cancer recurrences and 237 died due to their disease over a median follow-up of 3 years. Risks of these outcomes increased by 29 percent (95 percent CI, 1.10 to 1.51), 36 percent (1.14 to 1.63) and 51 percent (1.11 to 2.04), respectively, among diuretic users (n=8,517) vs nonusers.
Among beta-blocker users (n=7,145), the risk of breast cancer–specific death was higher by 41 percent (1.07 to 1.84) relative to nonusers.
Other blood pressure-lowering medications such as angiotensin II receptor blockers, calcium channel blockers and angiotensin-converting enzyme inhibitors were not associated with risks of breast cancer outcomes.
The present data should provide some reassurance that majority of the commonly prescribed antihypertensive medications are safe for older survivors in terms of breast cancer outcomes, researchers said. However, further studies are warranted to clarify and confirm the positive associations between diuretics and beta-blockers and risks of adverse breast cancer outcomes observed in this study.
“Given the increasing number of available antihypertensive medications, characterization of potential relationships between use of [these] medications and adverse breast cancer outcomes may help clinicians and women with breast cancer weigh the benefits and risks of different treatment options when managing hypertension,” they added.