Green Tea Extract in Treating Patients With Nonmetastatic Bladder Cancer

Criteria:

* Diagnosis of bladder cancer
* Bladder tumor discovered on cystoscopy within the past 60 days
* Invasive or non-invasive tumor
* Primary tumor may represent either an initial diagnosis or recurrent disease of any clinical stage
* No metastatic disease
* Must be an eligible candidate for a partial cystectomy, radical cystectomy, or trans-urethral resection of bladder tumor (TURBT)
* Has not undergone any treatment for superficial or invasive bladder cancer since the diagnostic cystoscopy
* TURBT or radical cystectomy is the planned curative surgical treatment
* ECOG performance status (PS) 0-1 OR Karnofsky PS 70-100%
* More than 30 days since any prior intravesical therapy or adjuvant chemotherapy
* More than 30 days since prior bladder surgery
* Biopsies are not considered surgeries
* No prior pelvic radiotherapy
* No concurrent systemic chemotherapy for any other cancer, except nonmelanoma skin cancer
* No concurrent NSAIDs (e.g., ibuprofen, naproxen, or cyclooxygenase-2 inhibitors) except =\< 81 mg aspirin per day
* Concurrent acetaminophen (Tylenol) or prescription opioids combined with acetaminophen (i.e., Percocet, Darvocet, Vicodin, Tylenol #3) allowed for pain
* No other concurrent investigational agents
* White Blood Cell (WBC) \>= 3,000/mm\^3
* Platelet count \>= 100,000/mm\^3
* Hemoglobin \>= 10 g/dL
* Alkaline phosphatase =\< upper limit of normal (ULN)
* Bilirubin =\< ULN
* Asparate Aminotransferase (AST) and Alanine Transaminase (ALT) =\< ULN
* Sodium 135-144 mmol/L (inclusive)
* Potassium 3.2-4.8 mmol/L (inclusive)
* Chloride 85-114 mmol/L (inclusive)
* Bicarbonate \>11 mEQ/dL
* Negative pregnancy test
* Fertile patients must use effective contraception
* Willing to avoid green tea beverages and green tea-containing products during study participation
* No evidence of other cancers, except nonmelanoma skin cancer
* No history of allergic reactions attributed to tea or to any of the compounds of similar chemical or biologic composition to Polyphenon E or any of the inactive ingredients in Polyphenon E capsules
* No uncontrolled intercurrent illness including, but not limited to, any of the following: Ongoing or active infection, Symptomatic congestive heart failure, Unstable angina pectoris, Cardiac arrhythmia, Psychiatric illness/social situations that would limit study compliance
* More than 24 hours since prior and no concurrent consumption of any other green tea supplements or more than 2 cups (16 oz) of green tea either through dietary sources or through nutritional supplementation
* Topical cosmetics (i.e., lotions, shampoos, makeup) that contain green tea are allowed
* Creatinine normal
* Not pregnant or nursing