Hypertension, use of antihypertensive medications and breast cancer survival among Black women.

Black women in the United States experience disproportionately high breast cancer mortality and have high rates of comorbid hypertension; however, the associations of hypertension and antihypertensive medication use with breast cancer survival are unclear. We examined these associations among 2474 Black Women's Health Study participants with invasive breast cancer. Hypertension and antihypertensive medication use were assessed biennially, and breast cancer diagnoses were confirmed through medical records and cancer registries. We used Cox proportional hazards models, adjusted for clinical and lifestyle factors and cancer treatment, to estimate hazard ratios (HR) for breast cancer-specific death. In the full study population, the HR for untreated hypertension compared to no hypertension was 1.17 (95% CI = 0.75-1.82), while the HR for treated hypertension compared to no hypertension was 0.81 (95% CI = 0.60-1.10). For ER+ cases, there was no association between untreated hypertension and breast cancer specific-death (HR = 0.96, 95% CI = 0.50-1.82), but a strong inverse association between treated hypertension and breast cancer-specific death (HR = 0.53, 95% CI = 0.34-0.83). In contrast, for ER- cases, we observed an increased risk of breast cancer specific death among those with untreated hypertension (HR = 2.19, 95% CI = 1.09-4.39), but there was little evidence of an association with treated hypertension (HR = 1.32, 95% CI = 0.80-2.19). Overall, our findings indicate that Black breast cancer patients with hypertension have better survival when their hypertension is treated, possibly due to regular healthcare engagement or the tumor suppressing actions of antihypertensive medications. Randomized trials are needed to establish causality and inform optimal cardiovascular management in oncology.