Cardiotoxic effects of anthracycline-based therapy: what is the evidence and what are the potential harms?

Despite the known cardiotoxic effects of doxorubicin and other anthracyclines, no evidence-based guidelines exist for the surveillance and prevention of chemotherapy-induced cardiotoxicity in adult survivors of breast cancer who have had limited previous doses of anthracyclines (ie, total cumulative dose 240 mg/m2), or limited-dose anthracyclines followed by trastuzumab-based regimens. Nonetheless, some national and international cardio-oncology and cardiac-imaging organisations recommend increased cardiac surveillance during or after treatment, measurement of cardiac biomarkers and other surrogate endpoints, and in some cases initiation of cardioprotective drug therapy in asymptomatic women. However, two unintended potential harms of such approaches are medicalisation (definition and treatment of subclinical heart problems without high-level evidence for a consequent reduction in the incidence of subsequent heart failure or cardiac deaths) and increased health-care costs when the value of providing that care is unknown. Whether existing cardio-oncology or imaging guideline recommendations will provide increased value or cause increased distress and lower health-related quality of life is unknown. Further research is needed to assess the long-term benefits, harms, and value of expanded cardiac surveillance, use of surrogate cardiac biomarkers, and prophylactic cardioprotective therapy in asymptomatic women with limited exposure to anthracyclines.