Capecitabine and Pegylated Interferon Alfa-2a in Treating Patients With Recurrent or Progressive Brain Metastases Due to Breast Cancer

RATIONALE: Drugs used in chemotherapy, such as capecitabine, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Pegylated interferon alfa-2a may interfere with the growth of tumor cells. Giving capecitabine together with pegylated interferon alfa-2a may kill more tumor cells. PURPOSE: This phase II trial is studying how well giving capecitabine together with pegylated interferon alfa-2a works in treating patients with recurrent or progressive brain metastases due to breast cancer.