Underuse of anthracyclines in women with HER-2+ advanced breast cancer.

Anthracyclines are among the most active drugs in breast cancer. Because of excessive cardiotoxicity, their use in combination with trastuzumab has been discouraged in patients with human epidermal growth factor receptor (HER)-2(+) metastatic breast cancer. We sought to describe how this treatment paradigm influenced the use of anthracyclines in this patient setting. We analyzed a multi-institutional database containing the treatment history of 450 patients who received at least one trastuzumab-based regimen for HER-2(+) metastatic breast cancer. Patients were considered eligible for anthracyclines for metastatic disease if they were never exposed (NE) or had been previously exposed (PE) to an anthracycline in the neoadjuvant or adjuvant setting and had relapsed after 12 months from the last dose. We then assessed the use of anthracycline-based therapy after failure with the first trastuzumab-based regimen in eligible patients. Three-hundred twenty-one patients were considered eligible for anthracyclines. In total, 190 eligible patients developing disease progression during the initial trastuzumab-based therapy were analyzed. An anthracycline was administered as first salvage treatment in 14 NE and two PE patients. Another 15 NE and nine PE patients received an anthracycline as a further line of therapy. Of 119 eligible patients who died from breast cancer, only 30 received an anthracycline for metastatic disease. In conclusion, despite the fact that two thirds of the patients receiving trastuzumab-based therapy for HER-2 metastatic breast cancer are eligible for anthracyclines, these drugs are infrequently used nowadays to treat trastuzumab-refractory disease. A role for these compounds should be redefined in this patient subset.