Prevention and management of major side effects of targeted agents in breast cancer.

Targeted therapies have evolved dramatically over the last few years. The heterogeneity of breast cancer is now understood on a molecular level, and different targeted therapeutic strategies have been approved in an attempt to tailor treatment strategies. Although the incidence of side effects is expected to be low due to target specificity, this is not always the case. Adverse events such as congestive heart failure and life threatening diarrhoea are sometimes observed because of off-target drug effects. In this article, we discuss the incidence, prevention and management of serious adverse events associated with trastuzumab, lapatinib, and bevacizumab. We critically analyse the available evidence and provide some insights on how to manage these toxicities in the clinical setting.