Soy Protein/Effexor Hormone Therapy for Prostate Cancer

Randomized Study of Soy Protein and Effexor on Vasomotor Symptoms of Men With Prostate Cancer

RATIONALE: Soy protein/isoflavones and venlafaxine may help relieve hot flashes in patients receiving hormone therapy for prostate cancer. It is not yet known whether soy protein/isoflavones are more effective than venlafaxine when given together or with a placebo in treating hot flashes.

PURPOSE: This randomized phase III trial is studying soy protein/isoflavones and venlafaxine to compare how well they work when given together or with a placebo in treating hot flashes in patients receiving hormone therapy for prostate cancer.

OBJECTIVES:

Primary

• Assess the effect of soy protein/isoflavones and venlafaxine on the hot flash symptom severity score in patients undergoing hormonal manipulation for treatment of prostate cancer.

Secondary

• Assess the effect of soy protein/isoflavones and venlafaxine on quality of life of these patients.
• Monitor and assess the participant drop out rate.

OUTLINE: This is a randomized, double-blind, multicenter study. Patients are stratified according to severity of disease (metastatic vs nonmetastatic) and baseline severity of hot flashes. Patients are randomized to 1 of 4 treatment arms.

• Arm I: Patients receive oral placebo pill and oral soy protein/isoflavones powder once daily.
• Arm II: Patients receive oral venlafaxine and oral placebo powder once daily.
• Arm III: Patients receive oral venlafaxine and oral soy protein/isoflavones powder once daily.
• Arm IV: Patients receive oral placebo pill and oral placebo powder once daily. Treatment in all arms continues for 12 weeks in the absence of disease progression or unacceptable toxicity. After 12 weeks of treatment, patients in arms I and III receive a tapered dose of oral venlafaxine once daily for 1 week.

Patients complete a vasomotor symptom diary once daily beginning 7 days before the initiation of study treatment and continuing until the completion of study treatment. Quality of life is assessed at baseline and at week 12.

PROJECTED ACCRUAL: A total of 176 patients will be accrued for this study.

Inclusion Criteria:

• Histologic documentation of prostate cancer, any stage Life expectancy of > nine months
• Prior or current androgen deprivation for treatment or control of prostate cancer to include:
• Bilateral Orchiectomy
• LHRH agonist (with or without antiandrogen therapy) ie: leuprolide (Lupron), goserelin (Zoladex), bicalutamide (Casodex), flutamide (Eulexin), or similar agents
• Chemotherapy
• Radiation (Patients may undergo concurrent radiation therapy to the prostate, prostate + seminal vesicles, and/or pelvis). Seed implants are allowed
• Participant report of hot flash frequency of an average of four or more per day, as defined by sweating, flushing, sensation of warmth, night sweats (Average of 28 per week)
• Hot flashes must be moderate or severe (See appendix A for hot flash definitions)
• Grade 2 (Moderate flashes) are warmer, produce obvious perspiration, and last 2 to 3 minutes
• Grade 3 (Severe flashes) causes profuse perspiration, generate intense heat, last longer and interfere with ongoing activity
• Age >21
• No allergies to soy or dairy products
• No current use of SSRIs, SNRI's, MAOIs, or Linezolide
• No uncontrolled hypertension (160/90) or greater than Class I American Heart Association functional capacity
• No history of mania, hypomania, bipolar disorder, or anorexia nervosa
• No history of seizures
• No history of hepatic dysfunction)
• Must have a telephone
• Signed protocol-specific Informed Consent
• Participants consuming soy foods or soy based supplements must continue on a stable regimen during study participation
• Patients should maintain same treatment and medications for prostate cancer throughout entire study.
• No change in treatment for 2 weeks prior to registration.
• Current use of medications and herbal supplements for hot flashes are allowed if on a stable regimen throughout the entire study. (Does not include anti-depressants)

Exclusion Criteria:

• Anticipated changes in prostate cancer treatment plan (i.e., hormonal manipulation, changes in chemotherapy)
• Concurrent antidepressant therapy
• History of intolerance to venlafaxine
• Recent (within 14 days) use of venlafaxine (Effexor XRTM), monoamine oxidase inhibitor, SSRI (selective serotonin reuptake inhibitor), or SNRI (selective norepinephrine reuptake inhibitor)
• History of seizure disorder