Trial Information

A Phase II Clinical Trial to Evaluate 18F-Fluoroestradiol Positron Emission Tomography / Computerized Tomography (PET/CT) Guided Fulvestrant Therapy for Patients With Recurrent or Metastatic Breast Cancer

The majority of women diagnosed with breast cancer are post-menopausal, of which up to 75%
are estrogen (ER) and/or progesterone receptor (PR) positive. Even in pre-menopausal breast
cancer over half of all patients will have expression of these hormone receptors. Thus
therapeutic strategies targeting the estrogen receptor or its ligand are the most common
treatment offered in breast cancer. Despite substantial benefits now demonstrated with
selective estrogen receptor modulators (e.g. tamoxifen) and aromatase inhibitors (e.g.
anastrazole, letrozole and exemestane), a significant proportion of patients will still
unfortunately have or develop resistance to these hormonal therapies.

Despite approximately two-thirds of patients who are prescribed fulvestrant following prior
hormonal agents not benefiting from this therapy, clinicians are still offering this option
to all suitable women because of the lack of a better means of identifying the individual
responders.

To assess whether the recommended treatment is beneficial to a specific individual, the
disease burden is assessed before and following treatment. Conventional imaging techniques
such as the bone scan or computerized tomography (CT) can take several months to show a
successful response to treatment. Positron emission tomography (PET) can improve the
evaluation of women with breast cancer by providing an accurate assessment of the extent of
disease and unique information about tumor biology such as metabolic activity.