Cardiotoxicity of tyrosine-kinase-targeting drugs
The development of the so-called "targeted therapies", particularly those drugs that inhibit the activity of tyrosine kinases, has become a remarkable progress in the treatment of neoplastic diseases. The small molecule tyrosine kinase inhibitor (TKI) imatinib has revolutionized the treatment of chronic myeloid leukemia, and trastuzumab, the humanized monoclonal antibody against the ERBB2 receptor tyrosine kinase, has proved to have a high efficacy in 25% of breast cancers. On the basis of treatment success it is expected that targeted therapies will spread its use in the future. Recent data has shown that some of these therapies are associated with certain cardiotoxicity ranging from asymptomatic mild left ventricular dysfunction to congestive heart failure through different mechanisms. However, rates of cardiotoxicity associated with TKI are not well known mainly because clinical trials usually do not include predefined cardiac endpoints or the assessment of left ventricular function before and during treatment. In addition, it is especially difficult to diagnose heart failure in patients with some kinds of cancer who have many reasons to develop dyspnoea. Here we summarize what is known up to date about the cardiotoxicity of drugs targeting the tyrosine kinases. Being aware of the risk of using these drugs is particularly important to early detect and institute the appropriate treatment to prevent irreversible myocardial injury, especially when some neoplastic diseases, as haematological or breast cancers, can affect to young people with an estimated long-term survival.