Chemotherapy-Induced Cardiomyopathy in Breast Cancer Patients

Published by Kowsar. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The globally increasing incidence of cancer and its associated mortality has become a main challenge for humankind. This problem is more serious in developing countries, like Iran. Among different malignancies affecting people, breast cancer continues to be a main and worldwide cause of morbidity and mortality (1). Parallel to the increasing cancer burden in the modern world, there have been notable progresses in the management and therapy (either medical or nonmedical) of ma-lignancies including breast cancer, leading to a significant increase in the number of survived patients. This necessitates a close follow-up of such patients after their initial management (2). Patients with cancer face daily problems, some of which are difficult to overcome. Among these are possible complications associated with their chemothera-peutic regimens, particularly cardiovascular issues (3). Cardiotoxic nature of drugs used for the management of patients with cancer puts them at risk of numerous life-threatening cardiovascular events, like pericarditis, cardio-myopathy, cardiac arrhythmias, myocardial ischemia, and some others. Factors including cumulative drug doses, me-diastinal radiation, rate of drug administration, younger age, advanced age, female gender, hypertension, and pre-existing heart diseases are the recognized risk factors for developing early (within one year, but not acute) and late chemotherapy-induced cardiotoxicity (Table 1) (4). A wide variety of chemotherapeutic drugs can cause cardiotoxicity, among which anthracyclines, a main drug class used for patients with breast cancer, are one of the most common etiologies (5). Doxorubicin, a main member of this group, can lead to dose-dependent, irreversible and recurrent cardiotoxicity. It can cause myocardial damage through disorganization of myofibrillar morphology, necrosis and interstitial fibrosis (6). The other instance is Trastuzumab, a monoclonal antibody which inhibits growth of tumor cells that overexpress human epidermal growth factor 2 protein. This medication can cause reversible cardiac side effects regardless of the administration dosage, and with low possibility of recurrence (7). Some points were suggested to be beneficial in reducing the risk of cardiotoxicity following chemotherapy. Among these are decreasing the cumulative doses of anthracy-clines, administration of anthracyclines as infusion (rather than bolus), and the liposomal encapsulation of doxorubi-cin. Using β receptor blockers (like carvedilol or metopro-lol), angiotensin-converting enzyme inhibitors, angioten-sin II receptor blockers, and using nutritional supplements (antioxidants like vitamin E) are …