• Potency rates at 12 months after BNS-RAP in patients receiving maintenance alprostadil
• Potency rates with or without assistance at 1, 3, 6, 9, and 18 months after BNS-RAP
• Erectile Dysfunction Penile Assessment (SHIMS-5) scores at 1, 3, 6, 9, and 18 months after BNS-RAP
• Penile length at randomization and at 1, 3, 6, 9, and 18 months after BNS-RAP
• Dropout rates in the alprostadil maintenance therapy group secondary to penile burning/pain after alprostadil usage

RATIONALE: Sildenafil and alprostadil may help patients who have undergone prostatectomy for prostate cancer to recover from erectile dysfunction.

PURPOSE: This randomized clinical trial is studying giving sildenafil together with alprostadil in treating patients undergoing nerve-sparing robotic-assisted radical prostatectomy for nonmetastatic prostate cancer.

OBJECTIVES:

Primary

• To determine the rate of erectile function (defined as the ability to achieve and maintain an erection for intercourse without pharmacological assistance) at 1 year following bilateral nerve-sparing robotic-assisted prostatectomy (BNS-RAP) without postoperative maintenance pharmacotherapy in patients with nonmetastatic prostate cancer.
• To describe whether early postoperative maintenance pharmacotherapy with sildenafil citrate can improve return of erectile function at 1 year postoperatively in these patients.
• To describe if early postoperative maintenance pharmacotherapy with sildenafil citrate can decrease the time-to-return of erectile function in these patients.

Secondary

• To describe whether early postoperative maintenance pharmacotherapy with alprostadil can improve return of erectile function at 1 year postoperatively in these patients.
• To describe if early postoperative maintenance pharmacotherapy with alprostadil can decrease the time-to-return of erectile function in these patients.
• To compare sexual function quality of life in patients undergoing early postoperative maintenance pharmacotherapy to those without early postoperative maintenance pharmacotherapy.
• To compare the rate of potency at 1, 3, 6, 9, 12, and 18 months in patients using sildenafil citrate versus alprostadil for early postoperative maintenance pharmacotherapy.
• To describe the dropout rate for alprostadil maintenance pharmacotherapy secondary to urethral pain in patients using 2% lidocaine lubricant.
• To describe if penile length is decreased following BNS-RAP.
• To describe if penile length at 1 year is different in patients who have return of potency versus those who have no return of potency.

OUTLINE: Patients receive 2 doses of intraurethral alprostadil prior to undergoing bilateral nerve-sparing robotic-assisted prostatectomy (BNS-RAP). Within 2 weeks after surgery, patients are randomized to 1 of 3 treatment arms. In arms I and III, treatment begins at the first postoperative visit.

• Arm I: Patients receive intraurethral alprostadil once daily for up to 9 months in the absence of unacceptable toxicity. Patients also receive a set of 3 doses of oral sildenafil citrate at least 48 hours apart monthly for up to 18 months.
• Arm II: Patients receive a set of 3 doses of oral sildenafil citrate at least 48 hours apart monthly for up to 18 months.
• Arm III: Patients receive oral sildenafil citrate once daily for up to 9 months in the absence of unacceptable toxicity. Patients also receive a set of 3 doses of oral sildenafil citrate at least 48 hours apart monthly for up to 18 months.

Patients undergo assessment of erectile dysfunction, penile length, rate of urinary incontinence, and sexual function quality of life at baseline (preoperatively) and periodically during study. Patients are also assessed using a self-reported diary that records daily maintenance therapy, nocturnal erections, pharmacotherapy for intercourse, and the results of pharmacotherapy usage (i.e., no erection, erection sufficient for penetration, or erection insufficient for intercourse).

After completion of study therapy, patient are followed periodically for up to 18 months.

• Prostate Cancer
• Sexual Dysfunction and Infertility

• Drug: alprostadil
• Drug: sildenafil citrate
• Other: questionnaire administration
• Procedure: laparoscopic surgery
• Procedure: quality-of-life assessment

DISEASE CHARACTERISTICS:

• Diagnosis of prostate cancer

  • Stage T3 or less disease
  • Gleason score ≤ 8 based on final surgical pathological biopsy results
  • Nonmetastatic disease as confirmed by CT scan, bone scan, or lymph node biopsy
• Concurrently enrolled on the Prostate Database Study (protocol no. 00149) at the City of Hope National Medical Center
• Scheduled to undergo bilateral nerve-sparing robotic-assisted prostatectomy
• Was able to achieve erections sufficient for intercourse prior to surgery AND has an Erectile Dysfunction Penile Assessment (SHIMS-5) score ≥ 22

PATIENT CHARACTERISTICS:

• Willing to participate on study for 18 months
• Able to maintain follow-up care at the City of Hope National Medical Center for visits 1, 3, 6, 9, 12, and 18 months post surgery
• No allergy to the prostaglandin PGE1, lidocaine, or sildenafil citrate

PRIOR CONCURRENT THERAPY:

• No concurrent nitrate therapy (including oral sublingual nitrates) for coronary artery disease
• No prior hormonal treatment for prostate cancer or low serum testosterone
• No concurrent cytochrome P450 3AY inhibitors (i.e., cimetidine, erythromycin, ketoconazole, or protease inhibitors)