Patients with bladder cancer will be participating in this study for the treatment of abnormal cells in the bladder that have returned after initial treatment OR have moved to a new site in the body.

Inclusion Criteria:

• You must have been diagnosed with bladder cancer that has recurred or moved to a new part of the body.
• You must have at least one tumor that can be physically measured or scanned by x-ray.
• You may not have had previous chemotherapy (drug) treatment OR you have had surgery followed by one chemotherapy treatment at least 4 months ago.

Exclusion Criteria:

• You may not have used an experimental medicine or device within the past month.
• Cancer that has spread to your brain.
• If you are unwilling or unable to take folic acid or vitamin B12 supplements.