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In Vivo Assessment of Tumor Receptor Levels by Positron Emission |
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 metastatic 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:
-
Documented metastatic ER+ (qualitative or quantitative) breast cancer (biopsy proven ER+ on
either the primary or a metastatic site of disease).
- Clinical staging (bone scan and/or CT of liver if needed) .
- The patient must have measurable or evaluable disease to assess therapeutic response.
- Patients must be adult women 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.
- Patients with visceral (such as hepatic involvement) metastatic breast cancer.
