When a breast cancer is sensitive to hormones, a hormone blocking agent may be used as part of the treatment for that specific breast cancer. Usually hormone blocking agents will be given after the patient has completed their breast cancer surgery, (and if prescribed) radiation therapy and chemotherapy. In some cases, however, hormone blocking therapy may be recommended as the first step to treat a patient’s breast cancer. This is called neoadjuvant hormone blocking therapy or neoadjuvant hormonal therapy.

Why give neoadjuvant hormone blocking therapy?

• to shrink the size of the breast cancer so that breast conservation therapy may be offered rather than a mastectomy
• to treat cancers that may erode into the muscle and allow a less radical surgery
• to treat cancers that may cause skin ulceration
• to treat patients who may not tolerate surgery, such as a frail elderly patient or a patient with severe heart disease
• to participate in a clinical trial assessing the effect of neoadjuvant hormonal therapy on hormone sensitive breast cancer

Neoadjuvant hormone blocking therapy does not work as quickly as neoadjuvant chemotherapy.  Patients taking neoadjuvant hormone blocking therapy may need several months to see an effect on their breast cancer, as opposed to patients receiving neoadjuvant chemotherapy where results may be seen after a few courses of chemotherapy. Neoadjuvant hormone blocking therapy has far fewer side effects than neoadjuvant chemotherapy and is usually very well tolerated by the patients receiving it. Neoadjuvant hormone blocking therapy has been successfully used extensively in Europe and is now commonly offered in the United States. It is a viable treatment option for many patients whose breast cancers are sensitive to hormones.