This phase I/II trial is studying the side effects of giving paclitaxel together with radiation therapy with or without trastuzumab and to see how well it works to kill any remaining tumor cells in patients who have undergone surgery for bladder cancer. Drugs used in chemotherapy, such as paclitaxel, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Radiation therapy uses high-energy x-rays to kill tumor cells. Paclitaxel may also make tumor cells more sensitive to radiation therapy. Monoclonal antibodies, such as trastuzumab, can block tumor growth in different ways. Some block the ability of tumor cells to grow and spread. Others find tumor cells and help kill them or carry tumor-killing substances to them. Giving paclitaxel together with radiation therapy and trastuzumab may kill more tumor cells. Giving these treatments after surgery may kill any remaining tumor cells.

PRIMARY OBJECTIVES:

I. To determine the acute toxicity (=< 90 days from protocol treatment start) from chemoradiotherapy including paclitaxel +/- trastuzumab and irradiation in non-cystectomy patients with or without her2/neu overexpression.

SECONDARY OBJECTIVES:

I. To determine the ability of patients with bladder cancer who are non-cystectomy candidates to complete this treatment program.

II. To evaluate the efficacy of this treatment program in achieving a complete response of the primary tumor.

III. To measure the 5-year disease-free and overall survival of patients with bladder cancer treated with transurethral resection of the bladder followed by chemoradiotherapy.

IV. To estimate the value of tumor and/or serum biomarkers as predictors of initial tumor response and recurrence-free survival.

OUTLINE: This is a non-randomized, multicenter study. Patients are assigned to 1 of 2 treatment groups according to HER2/neu status (HER2/neu 2+ or 3+ staining [group 1] vs HER2/neu 0 or 1+ staining [group 2]).

GROUP I: Patients receive paclitaxel intravenously (IV) over 1 hour on days 1, 8, 15, 22, 29, 36, and 43 and trastuzumab (Herceptin®) IV over 90 minutes on day 1 and then over 30 minutes on days 8, 15, 22, 29, 36, and 43. Patients also undergo radiotherapy once daily on days 1-5, 8-12, 15-19, 22-26, 29-33, 36-40, 43-47, and 50. Treatment continues in the absence of disease progression or unacceptable toxicity.

GROUP II: Patients receive paclitaxel and undergo radiotherapy as in group 1.

After completion of study treatment, patients are followed at 4-5 weeks, every 3 months for 1 year, every 4 months for 1 year, every 6 months for 3 years, and then annually thereafter.

Inclusion Criteria:

• Histologically or cytologically confirmed primary transitional cell carcinoma (TCC) of the bladder

  • Histologic evidence of muscularis propria invasion

• Meets 1 of the following stage criteria:

  • Stage T2-4a; NX, N0, or N1; and M0 disease
  • Clinical stage T1, grade 3/3 disease AND requires definitive local therapy

• Tumor involvement of the prostatic urethra allowed provided the following criteria are met:

  • Tumor was visibly completely resected
  • No evidence of stromal invasion of the prostate
  • No evidence of distant metastases by chest x-ray (or chest CT scan) within 8 weeks prior to registration
  • No evidence of distant metastases by abdominal/pelvic CT scan (or MRI scan) within 8 weeks prior to registration

• Has undergone transurethral bladder resection (as thorough as is judged safely possible) within the past 3-8 weeks, including bimanual examination with tumor mapping

• Sufficient tumor tissue available for HER2/neu analysis

• Not a candidate for radical cystectomy

• Performance status - Zubrod 0-2

• Absolute neutrophil count >= 1,800/mm^3

• Platelet count >= 100,000/mm^3

• Hemoglobin >= 8.0 g/dL (transfusion or other intervention allowed)

• Bilirubin < 2.0 mg/dL

• Serum glutamic oxaloacetic transaminase (SGOT) and serum glutamate pyruvate transaminase (SGPT) < 2.5 times upper limit of normal

• No hepatic insufficiency resulting in clinical jaundice and/or coagulation defects

• Creatinine =< 3.0 mg/dL

• Left ventricular ejection fraction (LVEF) >= 40% by multigated acquisition scan (MUGA) scan or echocardiogram

• No unstable angina and/or congestive heart failure requiring hospitalization within the past 6 months

• No transmural myocardial infarction within the past 6 months

• Not pregnant or nursing

• No nursing for 6 months after completion of study treatment (for patients receiving trastuzumab [Herceptin®])

• Negative pregnancy test

• Fertile patients must use effective contraception during and for 6 months after completion of study treatment

• Able to tolerate systemic chemotherapy and pelvic radiotherapy

• No other invasive malignancy within the past 3 years except nonmelanoma skin cancer

• No history of allergic reaction to study drugs

• No history of inflammatory bowel disease

• No acute bacterial or fungal infection requiring IV antibiotics

• No AIDS

• No other severe active comorbidity

• No prior systemic chemotherapy with anthracyclines or taxanes

• No prior systemic chemotherapy for TCC

• No prior pelvic radiotherapy