OBJECTIVES:

• Determine whether the biologic activity of locally advanced breast cancer as measured by retention of iodine I 124 iododeoxyuridine (IUdR) on positron emission tomography (PET) scans pre- and postchemotherapy is different between patients whose tumor shrinks after treatment in comparison to patients whose tumor is stable or continues to grow.
• Demonstrate that incorporation of IUdR into tumor is in the tumor DNA at 24-36 hours post injection, as documented by tissue analysis and immunohistochemistry and that this correlates with the subsequent change in tumor dimension and proliferative activity of the tumor.
• Compare the pre and post treatment results of fludeoxyglucose (FDG) PET scanning and IUdR PET scanning in the same breast lesions as a basis for assessment of the relative metabolic change during chemotherapy.
• Further assess the biologic activity of metastatic tumor sites and their changes in size following chemotherapy to standard parameters that are used to evaluate change in tumor size, obtained under clinical standard of care for breast cancer, which will include CT scans as well as bone scans.
• Assess the accuracy of noninvasive measurement of PET measurement of the left ventricular cardiac chamber clearance of radioactivity as a substitute for arterial plasma sampling for determining metabolic rates of FDG and IUdR uptake into tumors.
• Evaluate metabolic changes in tumors as they are affected by specific chemotherapy in comparison to changes in tumor dimensions.

OUTLINE: For this study, the chemotherapy administered for an individual patient is at the discretion of the patient's primary attending physician. After chemotherapy, the patient is evaluated for surgical resection of the tumor. If the tumor is unresectable, the patient may be offered radiation therapy.

The first group of positron emission tomography (PET) scans is performed within 2 weeks before the first dose of chemotherapy. The second group of PET scans occur no more than 7 weeks after chemotherapy and prior to local therapy, either surgery or radiation therapy.

The PET scan before initiation of chemotherapy consists of 4 imaging sessions. There is one iodine I-124 iododeoxyuridine (IUdR) PET scan (3 imaging sessions) at 1, 4-8, and 24 hours after IUdR infusion, followed by one fludeoxyglucose (FDG) PET scan (1 imaging session) 45 minutes after FDG infusion.

PROJECTED ACCRUAL: Approximately 20 patients will be accrued for this study.