Phase II Study of Isoflavone G-2535 (Genistein) in Patients With Bladder Cancer

Inclusion Criteria: * Participants eligible for this study will have been evaluated by diagnostic office cystoscopy and found to have a bladder tumor; enrollment (signing of the consent form) must be within 60 days of pre-study cystoscopy demonstrating bladder tumor; the participant should have no evidence of distant metastasis and the primary tumor may represent either an initial diagnosis or recurrent disease of any clinical stage. Study participants must also be candidates for either subsequent cystoscopy/transurethral resection of bladder tumor (TURBT) or complete or partical cystectomy; histologic diagnosis is not required for enrollment; pre-enrollment diagnostic cystoscopy must be at least 45 days after treatment of the bladder with other agents such as BCG (participants with recurrent disease) * ECOG performance status 0 or 1 * Women of childbearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation * Ability to understand and the willingness to sign a written informed consent document * WBC \>= 3000/mm\^3 * Platelets \>= 100,000mm\^3 * Hemoglobin \>= 10 g/dL * Bilirubin =\< 1.4 mg/dl * AST =\< 3x normal * Creatinine =\< 2.0mg/dl * Serum calcium =\< 10.2 mg/dl, * Amylase =\< 3 x normal * Na \>= 125 and =\< 155 mmol/L * K \>= 3.2 and =\< 6 mmol/L * Cl \>= 85 and =\< 114 mmol/L * CO2 \>= 11 mEQ/dL * TSH within 1.3 x the upper range of norma…