Study participants will receive oxaliplatin intravenously (through a vein) every 3 weeks for as long as the cancer is under control and there are no serious side effects from the drug. If significant side effects develop, the dosage will be reduced, or the drug will be stopped. Blood tests to measure blood cell counts will be done at least once a week, and CT scans, chest X-rays, and MRIs will be done about once every 6 weeks to assess the tumor's response to the treatment. Additional blood tests will be done at the beginning of the first two treatment cycles to measure the amount of oxaliplatin in the blood, and urine will be collected during the first 24 hours of drug treatment to determine how much drug is eliminated by the body in urine.