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

This study has been completed.
Sponsor:
Collaborator:
Information provided by:
National Cancer Institute (NCI)
ClinicalTrials.gov Identifier:
NCT00765479
First received: October 2, 2008
Last updated: September 19, 2013
Last verified: August 2009
  Purpose

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.


Condition Intervention Phase
Prostate Cancer
Dietary Supplement: soy protein isolate
Other: placebo
Phase 2
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Masking: Double-Blind
Primary Purpose: Treatment
Official Title: Randomized Placebo-Controlled Adjuvant Study of Prevention of Prostate Cancer Recurrence After Radical Prostatectomy by Soy Protein Isolate

Resource links provided by NLM:


Further study details as provided by National Cancer Institute (NCI):

Primary Outcome Measures:
  • Two-year PSA failure rate (as surrogate for recurrence) [ Designated as safety issue: No ]
  • Time to PSA failure [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Isoflavone uptake or compliance as measured by serum isoflavone concentration [ Designated as safety issue: No ]
  • Serum total cholesterol levels [ Designated as safety issue: No ]
  • Steroid hormone axis as measured by serum testosterone, estradiol, and SHBG levels [ Designated as safety issue: No ]
  • Thyroid activity as measured by serum T3 and T4 levels [ Designated as safety issue: No ]
  • Apoptotic activity as measured by serum soluble Fas and Fas-ligand levels [ Designated as safety issue: No ]
  • Angiogenesis as measured by serum VEGF and bFGF levels [ Designated as safety issue: No ]
  • Oxidative stress as measured by serum 8-isoprostane levels [ Designated as safety issue: No ]
  • IGF axis as measured by serum IGF-1 and IGFBP-3 levels [ Designated as safety issue: No ]
  • Equol production as measured by serum equol concentration [ Designated as safety issue: No ]

Estimated Enrollment: 284
Study Start Date: December 2006
Study Completion Date: July 2013
Primary Completion Date: September 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Arm I
Patients receive an oral soy protein isolate beverage once daily.
Dietary Supplement: soy protein isolate
Given orally
Placebo Comparator: Arm II
Patients receive an oral casein placebo beverage once daily.
Other: placebo
Given orally

Detailed 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.

  Eligibility

Ages Eligible for Study:   40 Years to 75 Years
Genders Eligible for Study:   Male
Accepts Healthy Volunteers:   No
Criteria

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
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00765479

Locations
United States, Illinois
University of Illinois Cancer Center
Chicago, Illinois, United States, 60612-7243
Sponsors and Collaborators
University of Illinois at Chicago
Investigators
Principal Investigator: Maarten C. Bosland, DVSc, PhD University of Illinois at Chicago
Investigator: Roohollah Sharifi, MD University of Illinois at Chicago
  More Information

Additional Information:
No publications provided by National Cancer Institute (NCI)

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
ClinicalTrials.gov Identifier: NCT00765479     History of Changes
Other Study ID Numbers: CDR0000615902, UIC-2006-0706
Study First Received: October 2, 2008
Last Updated: September 19, 2013
Health Authority: Unspecified

Keywords provided by National Cancer Institute (NCI):
stage IIB prostate cancer
stage IIA prostate cancer

Additional relevant MeSH terms:
Prostatic Neoplasms
Genital Neoplasms, Male
Urogenital Neoplasms
Neoplasms by Site
Neoplasms
Genital Diseases, Male
Prostatic Diseases

ClinicalTrials.gov processed this record on October 19, 2014