Trial Information

Several publications have addressed the role of PET imaging for biological characterization
of breast cancer. A modest but significant correlation was reported between tumor grading
and FDG uptake. Few studies reported a positive correlation between SUV and the Ki-67
labeling index of malignant breast tumors. Others have correlated p53 expression in breast
cancer and FDG uptake. F18-Fluoro-3'-deoxythymidine (FLT) has been developed as a PET marker
for cellular proliferation has been developed for imaging cell proliferation and findings
correlate strongly with the Ki-67 labeling index in breast cancer. A 10-minute FLT-PET scan
acquired two weeks after the end of the first course of chemotherapy, has been shown in two
recent studies to be useful for predicting longer-term efficacy of chemotherapy regimens for
women with breast cancer.

In the current study FDG and FLT uptake and their ratios will be correlated with the risk
score results of the Oncotype gene-expression assay in patients with clinically negative
nodal disease planned for surgical removal of the tumor. It is our hypothesis that since
high uptake of these tracers implies aggressive behavior and rapid tumor growth, it might
well be that patients with high risk score on Oncotype will have high uptake of the PET
tracers and those with low risk score will show low-intensity uptake values. If this will be
the case, it might well be that in patients with non-conclusive oncotype results
(intermediate score) FDG and FLT uptake measurement will allow further dichotomy to 1.
Patients with intermediate score on Oncotype and high uptake of the PET tracers, suggestive
of aggressive behavior and 2. Patients with intermediate score on Oncotype and low uptake
of the PET tracers suggesting a less aggressive behavior.