Phase II Study for Solid Metastatic Tumors

1. To induce immunity-mediated tumor response outside the radiation field (abscopal effect) after chemo-radiation of a metastatic site in a pilot study of metastatic breast and other metastatic solid tumors. 2. To monitor the induction of a T cell response in patients with metastatic breast cancer. 3. To explore the role of PET scanning to assess tumor response/abscopal effect. Eligible are women with metastatic breast cancer and patients with other metastatic solid tumors who have achieved stable disease or have disease progression after systemic therapy and have at least three separate measurable sites of disease. Extent of metastatic disease is recorded both at CT and PET scanning. Radiation is given during systemic therapy to one of the lesions, 35 Gy in ten fractions over a two week interval, conformally to maximally spare normal tissue. GM-CSF treatment is given daily for fourteen days. At day 22 radiation is re-started and the same radiation dose is delivered to a second metastatic site, again with GM-CSF. Abscopal response is evaluated by assessing clinical and PET response in the non-irradiated measurable metastatic sites. A Phase II clinical trial based on an optimum two-stage Phase II Simon design is used to conduct this pilot study. Ten patients will be treated in Stage one; if there are no abscopal responses, the trial will be terminated. If there are one or more abscopal responses in Stage One, the trial will proceed to enroll an additional 19 patients.