Soy Protein in Preventing Recurrent Cancer in Patients Who Have Undergone Surgery for Stage II Prostate Cancer

Prostate Cancer Clinical Trial

Official title:

Randomized Placebo-Controlled Adjuvant Study of Prevention of Prostate Cancer Recurrence After Radical Prostatectomy by Soy Protein Isolate

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00765479
• Other study ID #: CDR0000615902
• Secondary ID: UIC-2006-0706
• Status: Completed
• Phase: Phase 2/Phase 3
• First received: October 2, 2008
• Last updated: September 19, 2013
• Start date: December 2006
• Est. completion date: July 2013

Study information

• Verified date: August 2009
• Source: National Cancer Institute (NCI)
• Contact: n/a
• Is FDA regulated: No
• Health authority: Unspecified
• Study type: Interventional

Clinical Trial Summary

RATIONALE: Soy protein may help prevent prostate cancer recurrence in patients who have undergone surgery for prostate cancer.

PURPOSE: This randomized phase II/III trial is studying how well soy protein works and compares it to a placebo in preventing recurrent cancer in patients who have undergone surgery for stage II prostate cancer.

Description:

OBJECTIVES:

• Determine whether soy protein isolate reduces the PSA failure rate and time to PSA failure within 2 years following radical prostatectomy in patients who are at high risk for prostate cancer recurrence.

• Determine the effects of soy protein isolate on intermediate biomarkers of steroid hormone axis (testosterone, estradiol, and SHBG) and thyroid activity (T3 and T4).

• Determine the effects of soy protein isolate on intermediate biomarkers of apoptosis (soluble Fas and Fas-ligand), angiogenesis (VEGF and bFGF), antioxidant activity (8-isoprostanes), and IGF axis (IGF-1 and IGFBP-3).

• Compare patients who are equol producers to those who are non-producers.

OUTLINE: This is a multicenter study. Patients are stratified according to hospital/clinic site (NYU vs UIC or Jesse Brown VA Medical Center vs other sites), number of high-risk characteristics (1 vs > 1), and race (African American vs non-African American [i.e., non-Hispanic White, Hispanic, Asian, and other]). Patients are randomized to 1 of 2 treatment arms.

• Arm I: Patients receive an oral soy protein isolate beverage once daily.

• Arm II: Patients receive an oral casein placebo beverage once daily. Treatment in both arms continues for up to 2 years in the absence of disease progression or unacceptable toxicity.

Blood samples are collected periodically for biomarker laboratory studies. Samples are analyzed to measure PSA levels by Tosoh PSA assay; cholesterol levels; isoflavone and equol concentrations by HPLC and ESA; and indicators of steroid hormone axis (testosterone, estradiol, and SHBG), indicators of thyroid activity (T3 and T4), indicators of apoptosis (soluble Fas and Fas-ligand), indicators of angiogenesis (VEGF and bFGF), indicators of oxidative stress (8-isoprostanes), and indicators of IGF axis (IGF-1 and IGFBP-3) by ELISA.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 284
• Est. completion date: July 2013
• Est. primary completion date: September 2011
• Accepts healthy volunteers: No
• Gender: Male
• Age group: 40 Years to 75 Years

Eligibility

DISEASE CHARACTERISTICS:

• Diagnosis of prostate cancer

• Clinically localized (T1c or T2) disease

• At high risk for recurrence, as defined by = 1 of the following:

• Preoperative PSA > 20.0 ng/mL

• Seminal vesicle invasion

• Extracapsular extension (excluding the bladder neck)

• Positive surgical margins (excluding apical margins)

• Micrometastases in any removed pelvic lymph nodes

• Final Gleason score of = 8

• Must have undergone radical prostatectomy for prostate cancer within the past 4 months

• Must have an undetectable PSA (< 0.07 ng/mL) at baseline, as measured by Tosoh PSA assay

• No clinical evidence of locally recurrent or metastatic disease

PATIENT CHARACTERISTICS:

• No significant intake of soy (i.e., more than once a week) at baseline including, but not limited to, any of the following:

• Vegetarians who regularly consume soy products (e.g., tofu)

• Individuals with customary Asian dietary habits, including regular intake of soy products

• Individuals who use soy-based milk replacements

• No anemia, iron deficiency problems, or subclinical iron deficiency at baseline

• No diabetes

• No thyroid disease

• No requirement for a sodium-free diet

• No substantive tendency to be constipated (i.e., = grade 2 constipation experienced regularly)

• No medical problem that would preclude the consumption of the soy containing beverage powder, including allergies against soy (or milk protein)

• No concurrent major disease, including major mental disease or major substance abuse problems

• No significant side effects from medication

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics

• No concurrent radiotherapy or hormonal therapy

• No other concurrent adjuvant therapy for prostate cancer

Study Design

Allocation: Randomized, Masking: Double-Blind, Primary Purpose: Treatment

Related Conditions & MeSH terms

• Prostate Cancer
• Prostatic Neoplasms

Intervention

Dietary Supplement:
• soy protein isolate
Given orally

Other:
• placebo
Given orally

Locations

Country	Name	City	State
United States	University of Illinois Cancer Center	Chicago	Illinois

Sponsors (2)

Lead Sponsor	Collaborator
University of Illinois at Chicago	National Cancer Institute (NCI)

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Two-year PSA failure rate (as surrogate for recurrence)			No
Primary	Time to PSA failure			No
Secondary	Isoflavone uptake or compliance as measured by serum isoflavone concentration			No
Secondary	Serum total cholesterol levels			No
Secondary	Steroid hormone axis as measured by serum testosterone, estradiol, and SHBG levels			No
Secondary	Thyroid activity as measured by serum T3 and T4 levels			No
Secondary	Apoptotic activity as measured by serum soluble Fas and Fas-ligand levels			No
Secondary	Angiogenesis as measured by serum VEGF and bFGF levels			No
Secondary	Oxidative stress as measured by serum 8-isoprostane levels			No
Secondary	IGF axis as measured by serum IGF-1 and IGFBP-3 levels			No
Secondary	Equol production as measured by serum equol concentration			No