Chemotherapy

Chemotherapy (drug treatment for cancer) may be used before surgery, after surgery, or instead of surgery in those patients who are unsuitable for surgery.

Hormonal treatment

Patients with estrogen receptor positive tumors will typically receive hormonal therapy after chemotherapy is completed. Typical hormonal treatments include:

• Tamoxifen is typically given to premenopausal women to inhibit the estrogen receptors

• Aromatase inhibitors are typically given to postmenopausal women to lower the amount of estrogen in their systems

• GnRH-analogues

• ovarian ablation or suppression is used in premenopausal women

Targeted therapy

In patients whose cancer expresses an over-abundance of the HER2 protein, a monoclonal antibody known as trastuzumab (Herceptin ®) is used to block the activity of the HER2 protein in breast cancer cells, slowing their growth. In the advanced cancer setting, trastuzumab use in combination with chemotherapy can both delay cancer growth as well as improve the recipient's survival. More recently, several clinical trials have also confirmed that in the adjuvant setting i.e. postoperative following breast cancer surgery, the use of trastuzumab for up to one year also delays the recurrence of breast cancer and improves survival.

Antiangiogenic therapy

A commercially available monoclonal antibody that blocks the activation of the VEGF receptor, bevacizumab, underwent testing in a randomized clinical trial whose preliminary results were announced by the National Cancer Institute in 2005. The preliminary data indicated that bevacizumab delays disease progression for up to five months over conventional chemotherapy, but survival was no better. Genentech, manufacturer of bevacizumab, has filed a supplemental biological application with the FDA for approval of bevacizumab in the setting of metastatic breast cancer, on the strength of the improvement in progression-free survival.