MRI and Magnetic Resonance Spectroscopy Imaging in Patients Receiving Dutasteride for Benign Prostatic Hypertrophy and Low-Risk Prostate Cancer

RATIONALE: Diagnostic procedures, such as MRI and magnetic resonance spectroscopy imaging, may help in learning how well dutasteride works in patients with benign prostatic hypertrophy and low-risk prostate cancer.

PURPOSE: This clinical trial is studying MRI and magnetic resonance spectroscopy imaging in patients receiving dutasteride for benign prostatic hypertrophy and low-risk prostate cancer.

OBJECTIVES:

Primary

* To determine whether there is a decrease in the extent of prostate cancer as measured by endorectal MRI and magnetic resonance spectroscopy imaging in patients with symptomatic benign prostatic hypertrophy and low-risk prostate cancer treated with dutasteride for 6 months.

Secondary

* To monitor the effects of dutasteride on serum testosterone, dihydrotestosterone, and free and total prostate-specific antigen (PSA).
* To monitor the effects of dutasteride on symptom and quality-of-life indices.

OUTLINE: Patients receive oral dutasteride once daily for 6 months.

Patients undergo endorectal MRI and magnetic resonance spectroscopy imaging at baseline and at 1, 3, and 6 months.

Patients complete quality-of-life questionnaires using the International Index of Erectile Function Questionnaire, American Urological Association Symptom Index, Functional Alterations due to Changes in Elimination, and Spitzer Quality-of-Life Index at baseline and at 1, 3, and 6 months.

Eligibility Criteria:
Inclusion criteria:

* Histologically confirmed adenocarcinoma of the prostate

  * Clinical stage T1b, T1c, or T2a disease
  * Gleason score ≤ 6
  * Maximal prostate-specific antigen (PSA) \< 10 ng/mL
* Demonstrates intra-prostatic metabolite abnormalities, consistent with adenocarcinoma of the prostate (i.e., ≥ 3 voxels with magnetic resonance spectroscopy imaging \[MRSI\] scores 4-5) by baseline MRI and MRSI
* Has symptomatic benign prostatic hypertrophy and is currently undergoing watchful waiting OR opting to undergo permanent seed implant (i.e., brachytherapy), but requires neoadjuvant androgen suppression for prostate shrinkage
* No regional lymph node involvement
* No evidence of distant metastases
* Zubrod performance status 0-1
* Able to swallow and retain oral medications

Exclusion Criteria:

* Other prior or concurrent invasive cancer, other than localized basal cell or squamous cell carcinoma of the skin
* Contraindications to MRI/MRSI, including any of the following:

  * Prostate biopsy (within the past 8 weeks) and any continued post-biopsy bleeding
  * Rectal bleeding
  * Anal fissures
  * Rectal surgery (end-to-end anastomosis)
  * Inflammatory bowel disease
  * Prior radical prostatectomy
  * Hip replacement
  * Certain types of penile implants
  * Vascular clips
  * Known anaphylactic reaction to latex compounds
  * Anticoagulant drugs
  * Severe claustrophobia
  * Cardiac pacemaker
  * Metal in eye
  * Any other metallic or foreign object in the body
* Unstable serious co-morbidities including, but not limited to, myocardial infarction, coronary artery syndrome, cardiac arrhythmias, symptomatic congestive heart failure, or cerebrovascular accident
* Major medical or psychiatric illness that, in the investigator's opinion, would preclude the completion of treatment and interfere with follow up
* Known hypersensitivity to any 5α-reductase inhibitor or drug chemically related to the study drug
* Prior radical surgery (prostatectomy) or cryosurgery for prostate cancer
* Prior pelvic irradiation, prostate brachytherapy, or bilateral orchiectomy
* Prior or concurrent cytotoxic chemotherapy for prostate cancer
* Prior hormonal therapy, such as luteinizing hormone-releasing hormone agonists (e.g., goserelin or leuprolide acetate), antiandrogens (e.g., flutamide or bicalutamide), or estrogens (e.g., diethylstilbestrol)
* Prior or concurrent finasteride, dutasteride, other drugs with known antiandrogenic properties (e.g., spironolactone or progestational agents), or any dietary or herbal supplement (e.g., selenium, vitamin E, saw palmetto, or PC-SPES)