Can adding bevacizumab to chemotherapy before surgery improve response?

The authors aimed to evaluate the effectiveness and safety of combining bevacizumab (Avastin) and chemotherapy prior to surgery in breast cancer.

This study showed that adding bevacizumab to chemotherapy increased response rates among women with non-metastatic (has not spread) breast cancer.

Neo-adjuvant chemotherapy is treatment used to shrink a tumor before surgical removal. This therapy has been shown to improve the chances of overall survival of women with breast cancer.

Bevacizumab is a treatment that blocks the creation of blood vessels a tumor needs to grow. Bevacizumab has been shown to be effective in many types of cancer when used in combination with chemotherapy. The effectiveness of adding bevacizumab to neo-adjuvant chemotherapy for breast cancer is not yet clear.

This study compared the outcomes following standard chemotherapy and chemotherapy with bevacizumab.

This study analyzed the results of 9 previous trials, including 4967 women with non-metastatic breast cancer. Of these women, 50.1% received bevacizumab plus chemotherapy while 49.9% received chemotherapy alone. Rates of complete response (absence of cancer growth) were compared.

Bevacizumab increased the odds of a complete response by 34% compared to chemotherapy alone. This response was mainly seen in breast cancer that was not dependent on hormones (such as estrogen) or the human epidermal growth factor receptor 2 (HER2) for growth. Bevacizumab increased the odds of a complete response by 38% in women with triple negative breast cancer (not dependent on hormones or HER2 for growth) compared to chemotherapy alone.

Bevacizumab did not increase the number of severe side effects. Bevacizumab increased the rates of some side effects. These included low white blood cell levels, fever associated with low white blood cells and hand-foot syndrome (redness and swelling on the hands and feet).

The authors concluded that the addition of bevacizumab to chemotherapy improved response rates, particularly in patients with cancers not dependent on hormones or HER2 for growth.

This was a meta-analysis, combining the results of several studies that had slightly different definitions of complete response.