Chen L, et al. – Experts in this study aimed at assessing the use of antihypertensive medications and risk of adverse breast cancer outcomes in a SEER–Medicare population. In older women, results revealed a possible association of use of diuretics and β–blockers with increased risk of breast cancer outcomes.

Methods

• 14,766 women between ages 66 and 80 years diagnosed with incident stage I/II breast cancer between 2007-2011 were ascertained by using the linked Surveillance, Epidemiology and End-Results (SEER)-Medicare database.
• They acquired medicare Part D data to characterize women's post-cancer use of various antihypertensive medications.
• Furthermore, outcomes included a second breast cancer event (SBCE, a composite outcome defined as the first of a recurrence or a second contralateral primary breast cancer), breast cancer recurrence, and breast-cancer specific mortality.
• Hazard ratios (HRs) and their associated 95% confidence intervals (Cis) were calcuted by using time-varying Cox proportional hazard models.

Results

• This study delineated 791 SBCEs, 627 breast cancer recurrences, and 237 breast cancer deaths over a median follow-up of 3 years.
• As per findings, use of diuretics (n=8,517) after breast cancer diagnosis was associated with 29% (95% CI: 1.10-1.51), 36% (95% CI: 1.14-1.63) and 51% (95% CI: 1.11-2.04) higher risks of a SBCE, recurrence, and breast cancer death, respectively.
• They revealed 41% (95% CI: 1.07-1.84) higher risk of breast cancer death in β-blockers users (n=7,145) than nonusers.
• Results did not find any association of use of angiotensin II receptor blockers, calcium channel blockers and angiotensin-converting enzyme inhibitors with risks of breast cancer outcomes.