Cardiotoxicity associated with trastuzumab in normal clinical practice

Abstract

Objective: To evaluate the incidence of cardiotoxicity associated with treatment with trastuzumab in clinical practice by describing its characteristics, progress and associated risk factors.

Methods: Retrospective observational study of patients with HER2-positive breast cancer treated with trastuzumab in the fi rst quarter of 2007 in a tertiary hospital. Follow-up was performed from start of treatment until the end of March 2008. The data sources used were the oncological computer program Oncowin® from the pharmacy department and the patient clinical history. We gathered variables related to patient baseline characteristics, treatment and safety.

Results: The study included 61 patients. 19 women (32.8%) presented cardiotoxicity, which was the second most common adverse affect of those frequently attributed to the treatment. The average time for toxicity to appear was 7 months, with an average FEVI decrease of 15.6 +/- 9.1 points. In 63.2% of the patients it was symptomatic, and its most frequent manifestation was stress-induced dyspnoea, with a single case of congestive heart failure. Cardiotoxicity led to suspension of treatment in 22.9% of the total patients, which was definitive for 7 out of the 14 patients who interrupted the treatment. No statistically significant differences were found for the possible risk factors.

Conclusions: The incidence of cardiotoxicity in clinical practice is much higher than expected. The important clinical implication of this information and the increasing use of trastuzumab mean that there is a new challenge for the optimal treatment of HER2-positive breast cancer.