Gemcitabine With Or Without Oxaliplatin in Treating Patients With Locally Advanced or Metastatic Bladder Cancer

RATIONALE: Drugs used in chemotherapy, such as gemcitabine and oxaliplatin, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Giving more than one drug (combination chemotherapy) may kill more tumor cells. PURPOSE: This randomized phase II trial is studying how well giving gemcitabine together with oxaliplatin works compared to gemcitabine alone in treating patients with locally advanced or metastatic bladder cancer.