Possible new treatment for metastatic breast cancer

The authors aimed to determine the effectiveness and safety adding bevacizumab (Avastin) to a chemotherapy regimen in previously treated patients with metastatic (spread to other areas of the body) breast cancer.

Metastasis is the spread of cancer to other organs in the body. Patients with metastatic breast cancer are often treated with a variety of agents, but often develop drug resistance (treatments are no longer effective). FOLFOX is a combination of different chemotherapy agents (oxaliplatin [Eloxatin], 5-fluorouracil [Efudex], and leucovorin) that is often used in patients with metastatic breast cancer after they become resistant to other treatments.

FOLFOX6 has previously been used to treat colorectal cancer. Studies show that the addition of bevacizumab to this treatment improves prognosis (outlook) in colorectal cancer patients.

While the original FOLFOX6 regime has shown to be efficient in the treatment of metastatic breast cancer, the involvement of bevacizumab is still unknown.

The aim of this study was to evaluate the efficacy and safety profile of a combined treatment of bevacizumab and FOLFOX6 in women with metastatic breast cancer.

A total of 69 women with human epidermal growth factor receptor 2 negative (HER2-, not dependent on HER2 for growth) breast cancer were evaluated for this study. All patients had disease progression despite at least one prior chemotherapy. These women received the FOLFOX6 chemotherapy regimen and either 5 mg or 7.5 mg of bevacizumab.

The average progression-free survival time (time from treatment until disease progression) was 6.8 months. Average overall survival (time from treatment until death from any cause) was 10.5 months. 50% of patients showed a response to treatment (such as tumor shrinkage).

In patients who responded to treatment, the addition of bevacizumab improved the overall survival by 5.7 months and progression-free survival by 4.2 months. This was in comparison to the women who did not respond to the treatment.

There were no significant changes in the safety profile of FOLFOX6 by the involvement of bevacizumab. Any associated side effects were mild, including nausea (43.5% of patients), nerve damage (40.6%), vomiting (36.2%) and bleeding (33.3%). More severe side effects included neutropenia (low levels of neutrophils, a type of white blood cell) in 76.8% of patients and leukopenia (low levels of another type of white blood cell) in 52.2% of patients.

The authors concluded that the bevacizumab/FOLFOX6 regime is highly effective with a good safety profile in the treatment of metastatic breast cancer.