Abstract
BACKGROUND: Although nearly half of women with metastatic breast cancer (mBC) have hypertension, it is unclear whether hypertension management improves survival. We examined the influence of pharmacologic hypertension management on all-cause and breast cancer-specific mortality in patients with mBC. METHODS: We conducted a longitudinal cohort study of 1332 female patients with de novo mBC diagnosed 2008-2020, followed through 2021. We calculated person-year (PY) rates of all-cause and breast cancer mortality by use of antihypertensives (monotherapy or polytherapy [one vs. multiple drug classes]). Multivariable Cox regression was used to estimate the association between antihypertensives and mortality. RESULTS: Overall, 48.4% of patients with mBC had hypertension, which was greatest in Black women (64.6%). During follow-up, 52.9% were treated with antihypertensive medications (20.3% monotherapy; 32.5% polytherapy). All-cause mortality rates were lower in the polytherapy (21.4/100 PY) versus monotherapy (28.5/100 PY) group. All-cause mortality risk was 38% lower (adjusted HR = 0.62; 95% CI: 0.47-0.82) in the polytherapy group vs. monotherapy. This protection was significantly greater in Hispanic patients (HR = 0.40; 95% CI: 0.20-0.84) and suggested in Black patients (HR = 0.48; 95% CI: 0.22-1.05). Similarly, breast cancer mortality was lower in those treated with polytherapy versus monotherapy, particularly those with good medication adherence (HR = 0.43; 95% CI: 0.24-0.77). CONCLUSION: In patients with mBC, all-cause mortality risk was lower among those treated with antihypertensive polytherapy versus monotherapy, with the greatest risk attenuation seen among Hispanic women. Additional prospective studies are needed to examine comorbidity management strategies that may help patients with mBC extend life, particularly including women of color.