Adjuvants Immunologic/administration & dosage Administration Intravesical Antibiotics Antineoplastic/administration & dosage/adverse effects Antimetabolites Antineoplastic/*administration & dosage/adverse effects BCG Vaccine/administration & dosage Bias Cause of Death Confidence Intervals Deoxycytidine/administration & dosage/adverse effects/*analogs & derivatives Disease Progression Drug Administration Schedule Humans Mitomycin/administration & dosage/adverse effects Neoplasm Recurrence Local/*drug therapy/mortality/prevention & control Randomized Controlled Trials as Topic Saline Solution/administration & dosage Urinary Bladder Neoplasms/*drug therapy/mortality/pathology/prevention & control Gemcitabine