Bendamustine and Erlotinib in Treating Patients With Stage IIIB, Stage IIIC, or Stage IV Breast Cancer

RATIONALE: Drugs used in chemotherapy, such as bendamustine, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Erlotinib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth and by blocking blood flow to the tumor. Giving bendamustine together with erlotinib may kill more tumor cells. PURPOSE: This phase I/II trial is studying the side effects and best dose of giving bendamustine together with erlotinib in treating patients with stage IIIB, stage IIIC, or stage IV breast cancer.