In Vivo Assessment of Tumor Receptor Levels by Positron Emission Tomography
in Patients with Locally Advanced Breast Cancer
Principal Investigator:Farrokh Dehdashti, M.D.
Contact for further information: Helen Kaemmerer [(314)
362-7026]
Purpose:This study is designed to determine if positron emission tomography (PET) can predict
how patients with locally advanced or patients with chest wall recurrence of breast cancer will
benefit from hormone (tamoxifen) therapy. Patients with advanced estrogen-receptor positive
(ER+) cancer are treated by hormonal manipulation, and 55-60% of these women will respond
favorably. A small percentage of patients who ultimately respond to hormone therapy will
experience a symptomatic "flare reaction". This reaction is attributed to the temporary agonist
effect of the hormone and cannot be distinguished from disease progression clinically or
radiologically. To evaluate response to tamoxifen therapy in patients with ER+ breast cancer, PET
using [18F]-2-fluoro-2 deoxyglucose (FDG), a glucose analogue, and 16a-[18F] fluoro-17b-
estradiol (FES), an estrogen analogue will be done before and 7-10 days after institution of
hormone therapy in order to detect flare reaction at the subclinical state. We believe that the flare
reaction detected by PET imaging early after initiation of treatment may predict responsiveness to
hormone therapy in this group of patients. We expect that FES uptake and quantification of FDG-
PET results will identify women who are likely to benefit from tamoxifen therapy. In the future,
the added information gained from pathologic and functional tests may be used to individualize
treatment in women with advanced breast cancer.
Inclusion criteria:
- Biopsy proven ER+ (qualitative or quantitative) primary breast cancer.
- "Locally advanced disease" as defined by any of the following:
- Inflammatory breast cancer
- Fixed axillary lymph node
- Primary tumor >4 cm
- Tumor fixed to underlying pectoralis muscle
- Locally advanced disease with or without cervical lymphadenopathy
- Recurrent breast cancer involving the chest wall
-
The patient must have measurable or evaluable disease so that repeated biopsies can be done to
assess therapeutic response.
- Patients must be postmenopausal and able to give informed consent.
-
Results of PET will be provided to the referring physician and patient only if there is evidence
of potentially life-threatening abnormalities such as hepatic metastases.
Exclusions criteria:
- Patients who have already received hormonal treatment within the last 6 months.
- History of a prior malignancy.
