[Cardiotoxicity as undesired side effect in the treatment of breast cancer]

Improvement of methods used in breast cancer therapy resulted in increased treatment effectiveness and prolonged survival of patients. However, this is accompanied by increased frequency of adverse side effects, including cardiac toxicity, which is becoming a serious problem affecting the quality of life and overall survival of cancer patients. The risk of developing cardiovascular complications depends on the type and dose of therapeutic agent used. The highest risk of cardiotoxicity is associated with anthracyclines. They are used frequently in cancer therapy due to their high efficiency but show a dose-dependent toxicity to the cardiovascular system. Cardiotoxicity can also occur with other substances used in breast cancer chemotherapy, as well as with radiotherapy. Combining potentially cardiotoxic therapeutic agents, commonly used in combination therapy, may result in escalation of toxic side effects. Mechanisms of heart damage are different for various cardiotoxic agents, but symptoms usually involve heart failure, ischemic heart disease, arrhythmias, hypertension, valvular diseases or pericarditis and myocarditis. The practices used to reduce the risk of cardiotoxic effects of cancer therapy include evaluation of cardiac functions before treatment and constant monitoring during and after treatment. Furthermore, limited doses and modifications of anticancer agent administration patterns are employed, as well as simultaneous application of cardioprotective agents. Understanding of cardiotoxic mechanisms of agents used in breast cancer treatment can help to develop efficient cardioprotective substances. Because oxidative stress plays an important role in the toxicity of cancer therapy, compounds with antioxidant properties are a very promising target of research.