Pathophysiology and preventive strategies of anthracycline-induced cardiotoxicity

Cardiotoxicity is a well-known complication following treatment with anthracyclines. However, they are still widely used in chemotherapy for breast cancer, lymphoma, leukemia, and sarcoma, among others. Patient clinical characteristics, such as age, sex, comorbidities, anthracycline dose and infusion schedule, and the combined anti-cancer agents used, are diverse among cancer types. It is difficult to recommend guidelines for the prevention or management of anthracycline-induced cardiotoxicity applicable to all cancer types. Therefore, anthracycline-induced cardiotoxicity remains a major limitation in the proper management of cancer patients treated with an anthracycline-combined regimen. Efforts have been extensive to determine the mechanism and treatment of anthracycline-induced cardiotoxicity. Because cardiotoxicity causes irreversible damage to the myocardium, prevention is a more effective approach than treatment of cardiotoxicity after symptomatic or asymptomatic cardiac dysfunction develops. This article will review the pathophysiological mechanisms of anthracycline-induced cardiotoxicity and strategies for protecting the myocardium from anthracycline.

Early cardiac function monitoring for detection of subclinical Doxorubicin cardiotoxicity in young adult patients with breast cancer

PURPOSE

As doxorubicin cardiotoxicity is considered irreversible, early detection of cardiotoxicity and prevention of overt heart failure is essential. Although there are monitoring guidelines for cardiotoxicity, optimal timing for early detection of subclinical doxorubicin cardiotoxicity is still obscure. The purpose of this study is to determine optimal timing of cardiac monitoring and risk factors for early detection of doxorubicin cardiotoxicity in young adult patients with breast cancer.

METHODS

Medical records of 1,013 breast cancer patients diagnosed from January 2009 to December 2010 is being reviewed and analyzed. Properly monitored patients are defined as patients who underwent transthoracic echocardiography before and after the chemotherapy. The definition of subclinical cardiotoxicity (SC) either decreases left ventricular ejection fraction (LVEF) more than 10% or the LVEF declines under 55% from baseline without heart failure symptoms.

RESULTS

Twenty-nine out of 174 (16.7%) properly monitored young adult female patients (mean age, 52±10 years old) developed SC. The mean interval of cardiac evaluation of SC group was 5.5±3.0 months. Among the risk factors, the history of coronary artery disease, cumulative dose of doxorubicin ≥300 mg/m(2) and use of trastuzumab after doxorubicin therapy were associated with development of SC. At cumulative dose of doxorubicin 244.5 mg/m(2), SC can be predicted (sensitivity, 71.4%; specificity, 70.9%; area under the curve, 0.741; 95% confidence interval, 0.608-0.874; p=0.001).

CONCLUSION

In young adult patients with breast cancer, SC was common at cumulative dose of doxorubicin <300 mg/m(2) and early performance of cardiac monitoring before reaching the conventional critical dose of doxorubicin might be a proper strategy for early detection of SC.