Breast Cancer Survivors Face Higher Ischemic Stroke Risk in First Year Post-Dx

Oncology nurses play a critical role in the long-term surveillance of cancer survivors, who often face a significant burden of cardiovascular morbidity following treatment. A recent large-scale, population-based cohort study has identified a time-dependent association between breast cancer diagnosis and the risk of incident ischemic stroke.

Published in Neurology, the medical journal of the American Academy of Neurology, the research highlights that while the risk of stroke is elevated shortly after diagnosis, it tends to decline over the long term. For oncology nurses, these findings underscore the necessity of proactive stroke risk management and early cardiovascular assessment during the first year of survivorship.

The critical one-year window

The study analyzed data from 107,606 breast cancer surgery survivors and 322,818 matched cancer-free women from the Korean National Health Insurance Service (NHIS) database. Researchers found that the risk of ischemic stroke was most pronounced within the first year following a breast cancer diagnosis. Specifically, the subdistribution hazard ratio (sHR) for stroke was 1.59 during the first year of follow-up compared to cancer-free women.

For nursing professionals, it is vital to note that this association was even stronger in the very early stages of the journey — specifically at 3 and 6 months after diagnosis — across all age groups. While the risk remained slightly elevated at the three-year mark (sHR 1.17), it eventually reached a point where survivors had a slightly lower risk of stroke than the general population over the long term (sHR 0.94). This suggests that the highest intensity of monitoring should occur during the active treatment and immediate post-treatment phases.

Treatment modalities and stroke risk

The study provides granular data on how specific oncology treatments impact cardiovascular health, which is essential information for nurses coordinating care. Among survivors, the use of anthracyclines was associated with a 25% increased risk of stroke (sHR 1.25). Perhaps more significantly for those managing endocrine therapy, the combined use of tamoxifen and aromatase inhibitors carried a 49% increased risk (sHR 1.49).

Interestingly, radiation therapy was associated with a decreased risk of stroke (sHR 0.84) during the initial period, although this association became nonsignificant beyond the one-year mark. These results indicate that oncology nurses should be particularly vigilant when assessing patients prescribed anthracyclines or combination endocrine therapies, as these individuals may require more frequent cardiovascular screening.

Identifying at-risk populations

Beyond treatment types, certain sociodemographic and clinical factors significantly influenced stroke outcomes. The research identified that stroke risk was higher among survivors with low income, hypertension, diabetes, or those who were current smokers. Nurses should prioritize education on modifiable risk factors for these populations.

Age-specific data also revealed striking trends:

• Ages 18–44: This group saw the highest relative increase in risk during the first year, with an sHR of 2.28.
• Ages 45–54: Survivors in this bracket faced a nearly double risk (sHR 1.96) in the first year.
• Ages 65 and older: While the relative risk increase was lower (sHR 1.49), the absolute incidence rate of stroke was much higher due to baseline age-related factors.

Clinical implications for oncology nursing

The findings suggest that the impact of breast cancer on stroke risk evolves over time, requiring a shift in how nurses approach survivorship care plans. The elevated risk shortly after diagnosis suggests that the physiological stress of the disease, combined with the immediate toxicity of treatments, creates a vulnerable window for patients.

Nurses should consider the following actions based on the study’s conclusions:

• Baseline evaluations: Encourage cardiovascular assessments before the initiation of potentially cardiotoxic therapies like anthracyclines.
• Periodic monitoring: Monitor for thromboembolic events and cardiovascular toxicity throughout the first year of therapy.
• Optimization of comorbidities: Work with patients to manage blood pressure and glucose levels, as these remain significant contributors to stroke risk in survivors.
• Patient education: Inform patients about the symptoms of ischemic stroke, particularly those in high-risk treatment groups or younger age brackets who might not otherwise perceive themselves to be at risk.

While the study was limited to South Korean women and focused primarily on those who underwent surgery, its scale provides robust evidence for the global oncology community. By recognizing the time-dependent nature of stroke risk, oncology nurses can better tailor their interventions to protect survivors during their most vulnerable periods.

Reference

1. Shin DW, Cho J, Park JH, et al. Time-dependent association between breast cancer and risk of ischemic stroke. Neurology. 2026;106(Supplement):e2025-e2031. doi:10.1212/WNL.0000000000011264.