Chemotherapy-Induced Cardiotoxicity in Breast Cancer: A Growing Concern
Chemotherapy-induced cardiotoxicity (CIC) remains a significant challenge in breast cancer treatment, impacting treatment adherence and long-term quality of life for patients. Recent research highlights the increasing risk of cardiac dysfunction during and after chemotherapy, emphasizing the demand for proactive cardiac monitoring and intervention.
Understanding Chemotherapy-Induced Cardiotoxicity
Cardiotoxicity, or damage to the heart, is a known side effect of certain chemotherapy drugs. It can manifest in various ways, including weakening of the heart muscle, arrhythmias (irregular heartbeats) and heart failure. The risk is particularly elevated in patients undergoing aggressive treatment regimens or those with pre-existing cardiovascular conditions.
Recent Findings on Cardiac Risk Markers
A prospective Brazilian study presented at the 2026 American Psychosocial Oncology Society (APOS) Annual Meeting followed 50 patients with stage I to III breast cancer through six cycles of chemotherapy. Researchers evaluated changes in electrocardiograms (ECGs) and cardiac biomarkers to identify early indicators of CIC. Key findings include:
- QTc Prolongation: The prevalence of QTc prolongation, a risk factor for arrhythmias, significantly doubled from 13.04% at baseline to 26.09% after treatment (P < .001).
- Troponin I Elevation: Troponin I levels, indicative of myocardial injury, increased fivefold, rising from a mean of 2.22 ± 4.05 ng/mL to 11.43 ± 25.91 ng/mL (P < .001). A peak value of 126.1 ng/mL was recorded, demonstrating progressive heart muscle damage.
- Arrhythmia Increase: The incidence of arrhythmias tripled, increasing from 4.35% to 13.04% during the treatment period. Importantly, heart rate remained stable in most patients (93.48%), suggesting that rhythm disturbances are sensitive indicators of cardiac risk.
- Inflammatory Markers: C-reactive protein (CRP) levels showed a trend upward but the change was not statistically significant (P = 0.238).
Risk Factors and Prevalence
A retrospective, multicenter study found cardiotoxicity reported in 9.68% of 341 patients treated with anthracycline-based chemotherapy for breast cancer. Patients with pre-existing comorbidities had a 12-fold increased risk of developing anthracycline-induced cardiotoxicity.
The Importance of Longitudinal Cardiac Monitoring
Early detection of CIC is crucial for implementing cardioprotective strategies and improving patient outcomes. Continuous monitoring throughout chemotherapy, utilizing tools like Troponin I and ECGs, allows for timely intervention.
Future Directions
Further research is needed to optimize cardiac surveillance protocols in oncology populations and to identify the most effective cardioprotective measures. Integrated cardiac assessment and monitoring are essential components of comprehensive breast cancer care.
Reference
D’Agnostini NS, Batista de Azevedo L, Neto LCBS, et al. Cardiotoxicity in breast cancer patients undergoing chemotherapy: longitudinal evaluation of electrocardiographic alteration and cardiac biomarkers. Presented at the 2026 American Psychosocial Oncology Society Annual Meeting, Recent Orleans, LA; March 18-20, 2026. Poster 87.