Abstract
About 20% of patients with breast cancer overexpress or have amplification of the HER-2 oncogene, and the advent of anti-HER2 therapy has changed the natural history of the disease. Cardiotoxicity resulting from treatment with dual anti-HER2 blockade is a matter of considerable debate. Trastuzumab-related cardiac dysfunction is well recognized, but the cardiotoxic effect of pertuzumab has so far been less documented. We report a case of pertuzumab-related cardiotoxicity in the treatment of a young patient with metastatic HER2-positive breast cancer. The identification of such an adverse effect and the multidisciplinary management allowed us to safely maintain single anti-HER2 blockade with trastuzumab, which provided the patient with a good result in terms of oncologic disease control. This case illustrates that undesirable pertuzumab-related effects on the cardiovascular system may occur and require early identification, adequate multidisciplinary management, and better understanding of its safety profile.