A combination of bevacizumab and docetaxel is a safe and effective treatment in metastatic breast cancer

This study examined the safety and efficacy of bevacizumab and docetaxel in HER2 positive and negative metastatic breast cancer patients.

Tumors depend on angiogenesis, or the growth of new blood vessels, for growth. Vascular endothelial growth factor is a protein essential for the blood vessel growth that leads to cancer metastasis, or spread. Inhibitors of this protein are therefore used as a treatment to block tumor growth.

Docetaxel (Taxotere) chemotherapy, used in advanced cases of breast cancer, can lead to progression-free survival (the time before the disease progresses after treatment) of 10.3 months, and a measureable response rate, such as tumor shrinkage, in 70% of patients. Bevacizumab (Avastin) is a vascular endothelial growth factor inhibitor, often used in combination with chemotherapy. It has been shown to improve progression free survival times and response rates in patients with metastatic breast cancer that is HER2 negative (does not depend on the human epidermal growth factor receptor 2 for growth).

Bevacizumab used in combination with docetaxel improved progression free survival in HER2 positive patients, but treatments led to increased toxicities. However, previous studies have included doses of these drugs that are higher than are currently used in the United States. The current study examined the combination of bevacizumab and docetaxel at lower doses in HER2 positive and negative metastatic breast cancer patients.

This prospective study (the study is designed and patients are observed for outcomes) included 73 patients: 52 HER2 negative patients treated with bevacizumab and docetaxel, and 21 HER2 positive patients treated with bevacizumab, docetaxel, and trastuzumab (Herceptin), a HER2 inhibitor.

In HER2 negative patients, the average progression free survival time was 8.4 months. 60% of patients had progression-free survival at 6 months following treatment, and 31% of patients at 12 months. Overall survival was 92% at 6 months and 55% at 24 months following treatment. An objective response (such as tumor shrinkage) was seen in 58% of patients.

In HER2 positive patients, average progression free survival time was 13.3 months. 90% of patients had progression free survival at 6 months following treatment, and 81% of patients at 12 months. Overall survival was 100% at 6 months and 74% at 24 months following treatment. An objective response was seen in 81% of patients.

Common adverse events included fatigue, alopecia (hair loss), and nausea. 33 HER2 negative and 13 HER2 positive patients experienced Grade 3 (severe) or higher adverse events following treatment. Serious adverse events, including febrile neutropenia (low white blood cell counts combined with a fever) and renal (kidney) failure, were seen in 8% of HER2 negative patients, but none of the HER2 positive patients.

This study concluded that combining bevacizumab with docetaxel is a safe and effective treatment strategy for patients with HER2 positive or negative metastatic breast cancer.