Evaluation the Treatment of Tamoxifen of Low/Intermediate Risk Bladder Tumors

Patients with primary or recurrent low/intermediate-risk papillary urothelial carcinoma of
the bladder will undergo resection of all but one marker lesion, measuring at least 6mm but
no greater than 10mm, and biopsy of normal-appearing mucosa. Patients with a solitary tumor
will undergo only biopsy prior to treatment. A 2mm cold cup biopsy of the marker lesion will
always be performed to rule out a potential high-grade lesion and for assessment of
pretreatment immunohistochemistry expression levels of ERα, ERβ1, Ki-67 (proliferation
marker) and TUNEL (apoptosis marker). If there are multiple tumors, all lesions, except the
marker lesion will be resected and sent for analysis. These patients will not receive single
immediate post-operative intravesical instillation of mitomycin-C. They will then undergo a
12-week course of treatment with tamoxifen administered as a single daily oral dose of 20mg.
At the completion of therapy, patients will undergo resection of the marker lesion (or biopsy
of the tumor bed, if a complete response is observed) and biopsy of normal-appearing bladder
mucosa again. Toxicity evaluations will be performed at the beginning (day 3), midway (week
6), and at completion of treatment (week 12), prior to resection of the marker lesion. A
final assessment for toxicity will also be performed 30 days after completion of therapy as
well as a second definitive resection of the marker lesion. Urine samples will be obtained
with the index tumor in place (marker lesion), and after completion of treatment, at the time
of definitive transurethral resection of the index tumor, as part of the standard clinical
care of these patients, and at the discretion of the surgeon for assessment of urinary
cytology. The urine samples will not be utilized for the research study. All normal-appearing
bladder biopsies (pre and post-treatment), the additional tumors (in case of multiple
lesions), and the definitive resection of the marker lesion (in the absence of response to
therapy) will provide sufficient material for immunohistochemistry assessment of the
expression levels of ERα, ERβ-1, ERβ-2, ERβ-5, Ki-67, and TUNEL, and also for RT-qPCR for
mRNA analyses of ERα, ERβ-1, ERβ-2, and ERβ-5. The pretreatment biopsy of the marker lesion
will be performed with a smaller biopsy forceps and will provide limited material, sufficient
only for immunohistochemistry assessment of the expression levels of ERα, ERβ-1, Ki-67, and
TUNEL.

Inclusion Criteria:

Males and females age 21 or older. Histologic evidence of urothelial carcinoma of the
bladder. Low/Intermediate-risk papillary urothelial carcinoma of the bladder, at initial
occurrence or recurrent with >6 months interval free of disease.

Patients with multifocal tumors must have resectable lesions. Patients may be
treatment-naïve or have failed 1 previous regimen of intravesical therapy.

At least one endoscopically measurable tumor 6 - 10mm in diameter. Adequate hepatic and
renal function. Patient or authorized proxy needs to have signed the informed consent form.

Exclusion Criteria:

Patients with sessile appearing tumors, which may be invasive or high-grade. Diagnosis of
urothelial carcinoma involving the prostatic urethra or upper urinary tract.

Plans for pelvic radiation while participating in the study. Concurrent use of warfarin,
heparin, or chronic use of NSAIDs, including aspirin (other than cardioprotective doses of
80mg daily) within 30 days prior to registration or during the trial.

Concurrent use of selective serotonin reuptake inhibitors or aromatase inhibitors.

Chronic or acute renal or hepatic disorder or any other condition, medical or psychological
that, in the opinion of the investigator, could jeopardize the subject's safe
participation.

Any other investigational drug within 30 days prior to registration and during the study.

Women Exclusion Pregnant or lactating women. Personal history of endometrial cancer or any
abnormal uterine bleeding. Previous or concurrent treatment with SERM and/or hormonal
replacement therapy within 3 months of the study.